Citation Nr: 1304463 Decision Date: 02/07/13 Archive Date: 02/19/13 DOCKET NO. 05-00 416 ) DATE ) ) On appeal from the Department of Veterans Affairs Regional Office in Manila, the Republic of the Philippines THE ISSUE Entitlement to service connection for the cause of the Veteran's death under 38 U.S.C. § 1310. REPRESENTATION Appellant represented by: Joseph R. Moore, Esq. ATTORNEY FOR THE BOARD K. A. Kennerly, Counsel INTRODUCTION The Veteran served on active duty in the United States Navy from May 1946 to May 1956. He died in September 2003; the Appellant is his surviving spouse. Procedural History This matter comes before the Board of Veterans' Appeals (Board) on appeal from a July 2004 rating decision of the Manila, Republic of the Philippines, Regional Office (RO) of the Department of Veterans Affairs (VA), which denied the Appellant's claim of entitlement to service connection for the cause of the Veteran's death. The Appellant submitted a Notice of Disagreement (NOD) with this determination in August 2004, and timely perfected her appeal in December 2004. In January 2007, Board remanded this claim to the Appeals Management Center (AMC) to afford the Appellant with proper notice of the Veterans Claims Assistance Act of 2000 (VCAA) and to forward her claim to the California Department of Veterans Affairs (CDVA) (her designated representative at that time) to provide the CDVA an opportunity to submit a VA Form 646 on the Appellant's behalf. Thereafter, in November 2009, the Board denied the Appellant's claim. The Appellant subsequently submitted a notice of appeal (NOA) to the United States Court of Appeals for Veterans Claims (Court), indicating her disagreement with the denial of her claim of entitlement to service connection for the cause of the Veteran's death. The Court issued a September 2011 Memorandum Decision vacating the November 2009 Board decision and remanding the appeal for additional evidentiary development. Independent Medical Examination In August 2012, the Board requested an Independent Medical Examiner (IME) opinion to assist in determining the nature and etiology of the Veteran's death. The IME opinion was provided to the Board in September 2012 and the Appellant was provided a copy of this opinion thereafter. Waiver The Appellant submitted a private medical opinion in June 2012, with an addendum dated in December 2012. The Appellant specifically waived agency of original jurisdiction (AOJ) consideration of these opinions. See 38 C.F.R. § 20.1304 (2012). Hearing The Board additionally observes that all appropriate due process concerns have been satisfied. See 38 C.F.R. § 3.103 (2012). The Appellant has been accorded the opportunity to present evidence and argument in support of the claim. In her December 2004 substantive appeal [VA Form 9] she declined the option of testifying at a personal hearing. Virtual VA Records The Board has also reviewed the Appellant's electronic Virtual VA file. No additional, relevant records have been added to the electronic file. Referred Issue The issue of entitlement to a disability rating in excess of 30 percent for pulmonary tuberculosis, for accrued benefits purposes, has been raised by the record, but has not yet been adjudicated by the AOJ. As such, the Board does not have jurisdiction over this claim and it is referred to the AOJ for appropriate action. FINDINGS OF FACT 1. All relevant evidence necessary for an equitable disposition of the Appellant's claim has been obtained. 2. The Veteran died in September 2003. His death certificate lists the immediate cause of death as respiratory failure due to pneumonia and acute myelogenous leukemia. No autopsy was performed. 3. A Physician's Amendment was filed in May 2004 to correct the Veteran's death certificate, to include "pulmonary tuberculosis" in the section of the death certificate identifying "other significant conditions contributing to death but not resulting in the underlying cause given." 4. At the time of the Veteran's death, service connection had been in effect for pulmonary tuberculosis, considered 30 percent disabling, since December 1997. 5. The preponderance of the evidence supports a finding that the Veteran's service-connected pulmonary tuberculosis contributed substantially or materially to cause the Veteran's death. CONCLUSION OF LAW Resolving all doubt in favor of the Appellant, service connection for the cause of the Veteran's death is warranted. 38 U.S.C.A. § 1310 (West 2002); 38 C.F.R. §§ 3.102, 3.312 (2012). REASONS AND BASES FOR FINDINGS AND CONCLUSION In the interest of clarity, the Board will discuss certain preliminary matters. The Board will then render a decision. The Court Remand As was described in the Introduction, this case was vacated and remanded by a Court decision dated in September 2011. The Board wishes to make it clear that it is aware of the Court's instructions in Fletcher v. Derwinski, 1 Vet. App. 394, 397 (1991), to the effect that a remand by the Court is not "merely for the purposes of rewriting the opinion so that it will superficially comply with the 'reasons or bases' requirement of 38 U.S.C.A. § 7104(d)(1). A remand is meant to entail a critical examination of the justification for the decision." The Board's analysis has been undertaken with that obligation in mind. The September 2011 Court decision essentially concluded that the Board had not provided adequate reasons and bases for its reliance on an October 2004 VA medical opinion, which failed to acknowledge that a Physician's Amendment had been filed to correct the Veteran's death certificate, which now reflected that pulmonary tuberculosis (PTB) contributed to the Veteran's death. The Board subsequently determined that additional development of the Appellant's claim was required. Specifically, as indicated above, the case was referred for IME opinion to render an opinion as to the cause of the Veteran's death. The development requested by the Board has been accomplished. Specifically, the requested IME opinion was provided in September 2012. That opinion will be discussed below. I. The Veterans Claims Assistance Act of 2000 The Board has given consideration to the provisions of the Veterans Claims Assistance Act of 2000 (VCAA). The VCAA includes an enhanced duty on the part of VA to notify a claimant as to the information and evidence necessary to substantiate a claim for VA benefits. The VCAA also redefines the obligations of VA with respect to its statutory duty to assist claimants in the development of their claims. VCAA notice letters were sent to the Appellant regarding her cause of death claim under 38 U.S.C.A. § 1310 in April 2004, January 2007, and May 2008. These letters appear to be adequate. These notice letters also provided the Appellant with appropriate notice regarding effective date, as is required by the decision of the Court in Dingess v. Nicholson, 19 Vet. App. 473 (2006). The Board need not, however, discuss in detail the sufficiency of the VCAA notice letters or VA's development of the claim in light of the fact that the Board is granting the cause of death claim. Any potential error on the part of VA in complying with the provisions of the VCAA has essentially been rendered moot by the Board's grant of the benefit sought on appeal. Additionally, the Board finds reasonable efforts have been made to assist the Appellant in obtaining evidence necessary to substantiate her claim of entitlement to service connection for the cause of the Veteran's death. The evidence of record includes the Veteran's death certificate, the Appellant's statements, service treatment records, and VA treatment records. In addition, the following medical opinions were obtained during the course of the appeal: a VA medical opinion in October 2004, a private medical opinion in June 2012, an IME opinion in September 2012, and a second private medical opinion in December 2012. The Appellant has been accorded ample opportunity to present evidence and argument in support of her claim. See 38 C.F.R. § 3.103 (2012). Accordingly, the Board will proceed to a decision. II. The Merits of the Claim The Appellant seeks entitlement to service connection for the cause of the Veteran's death under 38 U.S.C. § 1310. Relevant Law and Regulations In order to establish service connection for the cause of a veteran's death, the medical evidence must show that disability incurred in or aggravated by service either caused or contributed substantially or materially to cause death. See 38 U.S.C.A. § 1310 (West 2002); 38 C.F.R. § 3.312 (2012). The death of a veteran will be considered as having been due to a service-connected disability when the evidence establishes that such disability was either the principal or a contributory cause of death. The issue involved will be determined by exercise of sound judgment, without recourse to speculation, after a careful analysis has been made of all the facts and circumstances surrounding the death of the veteran, including, particularly, autopsy reports. See 38 C.F.R. § 3.312(a) (2012). The service-connected disability will be considered as the principal (primary) cause of death when such disability, singly or jointly with some other condition, was the immediate or underlying cause of death or was etiologically related thereto. See 38 C.F.R. § 3.312(b) (2012). A contributory cause of death is inherently one not related to the principal cause. In determining whether the service-connected disability contributed to death, it must be shown that it contributed substantially or materially; that it combined to cause death; that it aided or lent assistance to the production of death. It is not sufficient to show that it casually shared in producing death, but rather it must be shown that there was a causal connection. See 38 C.F.R. § 3.312(c)(1) (2012); see also Gabrielson v. Brown, 7 Vet. App. 36, 39 (1994). Generally, minor service-connected disabilities, particularly those of a static nature or not materially affecting a vital organ, would not be held to have contributed to death primarily due to unrelated disability. See 38 C.F.R. § 3.312(c)(2) (2012). However, service-connected diseases or injuries involving active processes affecting vital organs should receive careful consideration as a contributory cause of the death, the primary cause being unrelated, from the viewpoint of whether there were resulting debilitating effects and general impairment of health to an extent that would render the person materially less capable of resisting the effects of other disease or injury primarily causing death. See 38 C.F.R. § 3.312(c)(3) (2012). The regulations also state that there are primary causes of death which by their very nature are so overwhelming that eventual death can be anticipated irrespective of coexisting conditions, but, even in such cases, there is for consideration whether there may be a reasonable basis for holding that a service-connected condition was of such severity as to have a material influence in accelerating death. In this situation, however, it would not generally be reasonable to hold that a service-connected condition affected a vital organ and was of itself of a progressive and debilitating nature. See 38 C.F.R. § 3.312(c)(4) (2012). Standard of Review In general, after the evidence has been assembled, it is the Board's responsibility to evaluate the entire record. See 38 U.S.C.A. § 7104(a) (West 2002). When there is an approximate balance of evidence regarding the merits of an issue material to the determination of the matter, the benefit of the doubt in resolving each such issue shall be given to the claimant. See 38 U.S.C.A. § 5107 (West 2002); 38 C.F.R. § 3.102 (2012). In Gilbert v. Derwinski, 1 Vet. App. 49, 53 (1990), the Court stated that "a veteran need only demonstrate that there is an 'approximate balance of positive and negative evidence' in order to prevail." To deny a claim on its merits, the preponderance of the evidence must be against the claim. See Alemany v. Brown, 9 Vet. App. 518, 519 (1996), citing Gilbert, 1 Vet. App. at 54. Factual Background Service Connection The Veteran served in the United States Navy from May 1946 to May 1956. He was granted entitlement to service connection for PTB on December 18, 1997, considered 30 percent disabling. The Veteran filed subsequent claims of entitlement to increased disability ratings for this condition in February 2002 and September 2003. The previously assigned 30 percent disability rating was continued by way of a September 2002 rating decision. The September 2003 rating decision was deferred shortly after the Veteran's death. The question of entitlement to an increased disability rating for accrued benefits purposes has been referred back to the AOJ for appropriate action. Post-Service Medical Records Following his 1955 diagnosis and treatment for PTB, the Veteran suffered several episodes of reactivation, the last documented in 1990. In June 2002, the Veteran participated in a general VA examination in conjunction with his claim for increased disability benefits for PTB. The Veteran's claims file was not reviewed in conjunction with the examination. At the time of the examination, the Veteran complained of having a cough and fever for the prior five days, associated with headache, shortness of breath, and chest, joint and back pain. His phlegm was noted as yellowish in color. The mycobacteriology preliminary report noted that the Veteran's concentrate acid fast stain was negative. There was no growth in two weeks. The VA examiner diagnosed the Veteran with minimal to moderate PTB, buls with pulmonary emphysema, activity undetermined. See VA General Examination Report, June 17, 2002. Periapical and apical views of the Veteran's chest also revealed minimal to moderate, mostly interstitial, infiltrates in buls, fine linear fibrotic strands at the lung bases, and thickened perihilar markings. The lung fields were hyperlucent, with low diaphragmatic domes and a narrow mediastinal shadow. The aorta was slightly tortuous, with minimal intimal calcification at the arch. The impression was: minimal to moderate infiltrates, buls; chronic bronchitic changes; pulmonary emphysema; and atheromatous aorta with possible slight continuous murmur. See VA X-ray Report, June 17, 2002. On September 8, 2003, the Veteran reported to the VA Emergency Room (ER) with complaints of a three-week history of chills, back and chest pain, cough with tinged hemoptysis, rigors and night sweats. He reported that after returning from a year in the Philippines, he began to feel ill on approximately August 16, 2003. Over the next week, he experienced worsening of the aforementioned symptoms. He noticed severe submandibular pain approximately one week prior to his ER visit, as his cough and hemoptysis worsened. His chest pain occurred only when he coughed. The Veteran stated that he believed his illness was a TB infection. A blood smear revealed numerous immature, lymph-like cells in all high power fields. Chest X-ray revealed infiltrate near the center line along the diaphragm of the right lung and infiltrate in the basilar portion of the left lung. The impression was severe lympho-proliferative diagnosis (lymphoma vs. leukemia) with B-symptoms, panlymphadenopathy, and numerous blast-like cells in peripheral blood (extremely high white count). It was noted that acute leukemia and TB should be ruled out. See VA Treatment Records, September 8, 2003. On September 9, 2003, a VA hematology consult noted that upon admission, the Veteran's white blood cell (WBC) count was 102,000 with about 90 percent blasts and lymphocytes. One year prior, the Veteran's WBC count was 309 and his hematocrit and platelets were normal. It was noted that the Veteran had a history of PTB and was hospitalized for treatment in the 1950s. He was a 50 pack per year smoker and had a history of hemaptysis in 2002. Chest X-rays revealed mild blunting of the left costophrenic angle, which suggested a small pleural effusion. New strand opacity in the right lung base was concerning for infection. TB could not be excluded. There was also vague, slightly reticulonodular opacity seen throughout the mid-right lung zone, which was also noted to possibly represent a component of infection. Finally, there was pleural thickening at the right lung apex, as compared to the previous study. The Veteran was diagnosed with acute leukemia, diffuse lymphadenopathy, pneumonia and/or TB, and hypertension. See VA Treatment Record, Hematology Consult, September 9, 2003. The Veteran was discharged from the VA hospital on September 16, 2003. Following bone marrow biopsy, lymph node biopsy, daunorubicin chemotherapy and packed red blood cell transfusion, the Veteran was diagnosed with acute biphenotypic (myeloid/T) leukemia, pneumonia and a history of PTB, treated; active TB was ruled out. See VA Treatment Record, Discharge Summary, September 8, 2003 - September 16, 2003. The Veteran again sought treatment from VA on September 19, 2003, his chief complaint that he was unable to swallow well for the prior three days. The Veteran's son also noticed white spots near the uvula. It was noted the Veteran had singular intravenous chemotherapy treatment to reduce his WBC count without good results. Accordingly, it was determined that he would receive no further chemotherapy. Chest X-rays revealed interval development of consolidation involving the left lower lobe and lingual, possibly representing worsening infection or pulmonary edema. There was a moderate sized loculated left pleural effusion. There were stable diffuse reticular opacities, possibly representing pulmonary edema versus chronic interstitial lung disease. Finally, there was a stable partial consolidation of the right lung base. The Veteran was diagnosed with thrush, pneumonia, severe mucositis and dyspnea/tachypnea and was admitted for palliative care. See VA Treatment Record, September 19 & 20, 2003. The Veteran's Death The Veteran died shortly thereafter. The death certificate listed the immediate cause of death as respiratory failure due to pneumonia and acute myelogenous leukemia. No autopsy was performed. In October 2003, the Appellant filed her claim of entitlement to service connection for the cause of the Veteran's death under 38 U.S.C.A. § 1310. In June 2004, VA received a copy of a May 2004 Physician's Amendment, which was filed to correct the Veteran's death certificate, to include "pulmonary tuberculosis" in the section of the death certificate identifying "other significant conditions contributing to death but not resulting in the underlying cause given." See Physician's Amendment, June 4, 2004. In July 2004, the RO denied the Appellant's claim, stating that the record did not contain competent medical evidence that the Veteran's cause of death was related to service or due to an event or experience that originated in military service. There was also no evidence that the Veteran suffered from leukemia at a compensable degree within one year after discharge from his military service. The RO noted the Appellant's contentions that the Veteran's death was related to his service-connected PTB. It was noted however, that the Veteran's VA treatment records did not show diagnosis or treatment for PTB immediately prior to his death. See Rating Decision, July 7, 2004. The Appellant submitted her NOD with this determination in August 2004. During the RO's continued development of the Appellant's claim, a VA medical opinion was obtained to determine the cause of the Veteran's death. The October 2004 VA medical opinion determined that it was less likely than not that the Veteran's PTB contributed to his death. In support of this opinion, the VA physician noted that the Veteran had been service-connected for TB with a history of reactivation in 1990. Chest X-rays dated in August 1991 revealed persistent right upper lobe scarring with fibrosis and retraction associated right hilar elevation and rightward mediastinal shift, consistent with old inflammatory disease, unchanged from the November 1990 associated right apical pleural thickening. Other than scattered strand areas of scar or atelectasis through both lungs, no new pulmonary air space disease was identified. The VA physician also reviewed the VA treatment records prior to the Veteran's death, as detailed above. See VA Medical Opinion, October 1, 2004. Ultimately, the VA physician concluded that the Veteran had been diagnosed with PTB in the 1950s with a history of reactivation in 1990. Reports of PTB inactivity prior to 2003 were based on a negative sputum acid-fast bacilli (AFB) culture and stable lung infiltrates. The Veteran's serial chest X-rays during confinement in September 2003, showed rapid changes in his lung infiltrates, making the etiology of these findings likely bacterial or vascular and not from PTB. Worsening of the infiltrates was noted on repeat chest X-ray five days after his release from the hospital. The VA physician stated that active PTB lesions were slow growing and did not progress at that rate, even if left untreated. The sputum AFB culture result for the 2003 confinement was negative after eight weeks. It was also reported in the Veteran's medical summary that his respiratory complaints were from a pneumonia, secondary to his immunocompromised state. He had leukemia and was given chemotherapy during his confinement, with reactivation of PTB lesions not found on chest X-ray. His death certificate stated respiratory failure as the immediate cause, with leukemia as the underlying cause. The Veteran's lung infiltrates were likely caused by pneumonia and not active PTB, and this infection was secondary to his leukemia and its complications. Id. In November 2009, the Board denied the Appellant's claim. Shortly thereafter, the Appellant submitted her NOA to the Court. A September 2011 Memorandum Decision vacated the Board's November 2009 decision, stating that the Board relied on the October 2004 VA medical opinion, which did not address the June 2004 submission of the Physician's Amendment, adding PTB to the Veteran's death certificate. As such, the claim was remanded back to the Board for further evidentiary development. In June 2012, the Appellant submitted a private medical opinion addressing the cause of the Veteran's death. Dr. P.C. noted that he had reviewed the Veteran's medical records. Initially, it was noted that primary PTB often did not cause symptoms and could go undiagnosed until it was found or it reactivated. In the case of reactivated PTB, the symptoms often started insidiously and could be quite variable although cough, weight loss, fatigue, fever and night sweats were present in half or more patients. (See Barnes, P.F.; Verdegem, T.D.; Vachon, L.A.; Leedom, J.M.; Overturf, G.D.; Chest roentgenogram in pulmonary tuberculosis. New data on an old test. Chest, 1988 Aug; 94(2): 316 - 20. PubMed PMID: 2456183. See also MacGregor, R.R.; A year's experience with tuberculosis in a private urban teaching hospital in the postsanatorium era. Am J Med. 1975 Feb; 58(2): 221 - 8. PubMed PMID: 1115069.) As the disease progresses, a cough could become productive of purulent sputum and hemoptysis could be present. If chest pain was present, it likely represented inflammation of the pleura with or without an effusion. (See Basboz, N. Clinical manifestations of pulmonary tuberculosis. In: UpToDate, Basow, D.S. (Ed), UpToDate, Waltham, MA, 2012.) Chest X-rays typically demonstrated involvement of the apical segments of the upper lobes but radiographs could also be normal in active TB. (See Marciniuk, D.D.; McNab, B.D.; Martin, W.T.; Hoeppner, V.H. Detection of pulmonary tuberculosis in patients with a normal chest radiograph. Chest. 1999 Feb; 115(2); 445 - 52. PubMed PMID: 10027446. See Private Medical Opinion, P.C., M.D., June 7, 2012. In the Veteran's case, it was noted that subsequent records demonstrated reactivation and treatment for TB on multiple occasions, with the last active period documented in 1990 and 1991. Pulmonary clinic notes from that time indicated that his infection was isoniazid resistant and sputum cultures for AFB were negative on multiple samples. In June 2002, the Veteran presented to a VA clinic with complaints of joint, chest, and back pain, shortness of breath, fatigue, and cough for the prior five days. At that time, his diagnosis was minimal to moderate PTB, buls with pulmonary emphysema activity undetermined. Dr. P.C. stated that based on this description, the Veteran's symptoms were consistent with reactivation of PTB. Id. Dr. P.C. recounted that the Veteran presented to the ER on September 8, 2003, with complaints of a one-month history of hemoptysis, fever, chills, sweats and weight loss. Laboratory work at that time revealed a WBC count of 102,500, hemoglobin of 10.4, and platelets of 116,000, all of which were concerning for an acute leukemia. A chest X-ray revealed mild blunting of the left costophrenic angle, which suggested a small pleural effusion. New strand opacity in the right lung base was concerning for infection. It was also noted that TB could not be ruled out. Vague slightly reticulonodular opacity was seen throughout the mid-right lung zone, which could have also been representative of infection. There was also progressive pleural thickening at the right apex as compared to the previous chest X-ray. Id. The Veteran was admitted to the hospital and underwent lymph node biopsy, bone marrow biopsy and flow cytometry on his peripheral blood, which revealed an acute biphenotypic leukemia which carried a very poor prognosis. He also had sputum cultures obtained that were eventually negative for mycobacterium presence after eight weeks of incubation. Dr. P.C. noted that the Veteran's sputum and blood cultures were also negative for any other bacterial pathogens that could cause pneumonia as well. The VA heme-oncology team determined that the Veteran's leukemia was so severe that he was not a candidate for therapeutic chemotherapy. He was discharged from the hospital with hospice services one week later with a diagnosis of acute leukemia and pneumonia that was treated with levofloxacin. Id. Dr. P.C. stated that despite the Veteran's presenting complaints of a one month history of hemoptysis, fevers, chills, sweats and weight loss and a chest X-ray that showed evidence of apical changes and concluded tuberculosis could not be ruled out, the discharge summary inexplicably stated, "...active TB ruled out." Dr. P.C. stated that if this conclusion was based on the results of sputum smears, it should be noted that microscopy only detects 53 percent of true positive TB infections. Although the Veteran's culture results were eventually negative for mycobacterium as well, sputum culture has only around 80 percent sensitivity, that is, one in five patients with active TB will have a negative culture. (See Levy, H.; Feldman, C.; Sacho, H.; van der Meulen, H.; Kallenbach, J.; Koomhof, H.; A reevaluation of sputum micrX-rayscopy and culture in the diagnosis of pulmonary tuberculosis. Chest. 1989 Jun; 95(6): 1193 - 7. PubMed PMID 2656111. Dr. P.C. noted that as is the case in almost every other pathologic state, the entire clinical picture must be correlated with the findings on laboratory and radiographic testing before diagnostic conclusions are made. Id. Unfortunately, after his September 16, 2003, discharge, the Veteran's symptoms continued to worsen and he was readmitted to the hospital four days later. He was noted to be afebrile with a WBC count of 102,600. A chest X-ray revealed, "interval development of consolidation involving the left lower lobe and lingula, may represent worsening infection or pulmonary edema." There was also a left pleural effusion and stable reticular opacities noted. Dr. P.C. stated that although these radiographic findings may have been due to active pneumonia, the Veteran had just completed 10 days of antibiotic therapy, had recent negative sputum and blood cultures and was afebrile upon arrival. As noted by the radiologist, it was likely that his X-ray findings were due to pulmonary edema as a result of his leukemia and leukostasis. He further noted that it is well known that pulmonary leukemic infiltration can cause X-ray findings of diffuse reticulonodular opacity, which would resemble the findings of progressive opportunistic infection or pulmonary edema. (See Kakihana, K.; Ohashi, K.; Akiyama, H. Pulmonary Complications Caused by Acute Leukemia. Journal of Coagulation Disorders. 2010 Oct; 2(3): 1 - 6.) Id. Dr. P.C. noted that the Veteran's original death certificate indicated his cause of death was respiratory failure with leukemia listed as a contributing cause. This certificate was later amended by the Veteran's treating physician and PTB was added as a contributing cause to the Veteran's death. After review of the medical records, Dr. P.C. opined that it was clear the Veteran's initial presenting symptoms as well as his radiographic studies were likely indicative of reactivation of PTB. Although the Veteran's sputum cultures were eventually negative, Dr. P.C. stated the poor sensitivity of that test does not rule out active PTB as a contributing case to the Veteran's death. Id. Dr. P.C. concurred with the 2004 VA medical opinion that the radiographic findings mentioned in the records were due to pulmonary leukemic infiltration from the Veteran's recently diagnosed acute leukemia, as opposed to some other bacterial pneumonia - especially given his lack of other signs or symptoms of infection and negative culture results. Notably however, Dr. P.C. stated that the 2004 VA medical opinion failed to consider the Veteran's original presenting complaints of fever, sweats and weight loss, as well as the initial radiographic findings suggestive of active PTB. After a thorough review of the medical records and in light of the fact that culture tests were noted as typically sensitive and other factors in the Veteran's clinical picture indicating reactivated PTB, Dr. P.C. stated that it was at least as likely as not that the Veteran suffered from active TB in September 2003, which contributed to respiratory failure and ultimately his death. Id. In August 2012, due to the complexities of the medical issues involved, the Board requested an IME opinion, pursuant to 38 C.F.R. § 20.901(d). The medical expert was to provide an opinion as to: (1) whether it is at least as likely as not (50 percent or greater probability) that the service-connected PTB caused or contributed substantially or materially to cause the Veteran's death and (2) whether it is at least as likely as not that the service-connected PTB accelerated the non-service connected conditions that ultimately caused the Veteran's death. See Board's IME Request, August 9, 2012. In September 2012, Dr. H.S. submitted his IME opinion. Initially, Dr. H.S. summarized the Veteran's medical history, dating from November 1955 through May 2002. He noted that chest X-rays from May 21, 2002 were compared to those obtained on August 29, 1991. Changes included right upper lobe scarring, retraction right hilum and shift of mediastinum. In summarizing the Veteran's September 2003 VA hospitalization, Dr. H.S. stated that the presenting complaints of fever, sweats and weight loss were common to many diseases; not only to TB but also to leukemia. Pertinent laboratory findings included a WBC count greater than 100,000 with a marked predominance of "blasts". A chest X-ray, when compared to the May 21, 2002, X-ray, revealed new stranding opacity at the right lung base, vague reticular nodular opacities in the right mid-lung zone and increased pleural thickening at the right apex. There was blunting of the left costophrenic angle. Dr. H.S. stated that the initial X-ray findings and the subsequent evolution of the abnormalities were not at all typical of TB. See IME Opinion, September 28, 2012. The Veteran was treated with hydration, ceftriazone and azithromycin for possible pneumonia and metoprolol for elevated blood pressure. A diagnosis of biphenotypic leukemia (myeloid/T-cell) was promptly made following a bone marrow aspirate and supraclavicular node biopsy. Within several days of admission there was an agreement between the Veteran and his physicians to pursue palliative care since the leukemia carried a very poor prognosis. He was treated with daunorubicin and hydroxyurea without effect. Since the Veteran wished to return to the Philippines, he left the hospital prematurely, only to return within four days with an overwhelming infection characterized as mucositis involving his mouth, throat and probably esophagus, as well as a rapidly progressing pneumonia. The September 20, 2003 chest X-ray showed consolidation of the left lower lobe, lingual and a loculated left pleural effusion with stable findings in the right lung. He died within two weeks of the original diagnosis of leukemia. Id. Dr. H.S. noted that from September 8, 2003 to September 21, 2003, the Veteran's WBC count varied from 102,000 to 122,000, with leukemic cells in the periphery accounting for up to 93 percent of the white cells. His neutrophils (cells required to fend off bacterial infection) ranged from one to four percent of the total cells. By September 20, 2003, the Veteran had developed consolidation in his left lower lobe and lingula and a loculated left pleural effusion. Dr. H.S. stated that the Veteran died due to an aggressive leukemia that resulted in an immunocompromised state. The rapidity and pattern of the pneumonia was not considered at all typical of TB but rather suggested an opportunistic fungal, gram-negative or gram-positive bacterial infection of the lung and a probable fungal infection causing the mucositis. As a result, Dr. H.S. concluded that the Veteran's service-connected PTB did not cause or contribute substantially or materially to cause the Veteran's death, nor did it accelerate the non-service connected conditions that ultimately caused the Veteran's death. Id. In response to the September 2012 IME report, the Appellant submitted a December 2012 addendum to Dr. P.C.'s original June 2012 medical opinion. Dr. P.C. noted that he had again reviewed the Veteran's service and medical records as well as the September 2012 IME report. Dr. P.C. briefly reiterated that the Veteran had a history of PTB that was diagnosed and initially treated in 1955. His service-connected PTB had several episodes of reactivation, with the last documented in 1990. In June 2002, the Veteran presented to a VA clinic with complaints of joint, chest and back pain, shortness of breath, fatigue and cough of five days duration. His diagnosis at that time was minimal to moderate PTB, buls with pulmonary emphysema activity undetermined. Based on this description, Dr. P.C. stated that the Veteran's symptoms were consistent with reactivation of PTB. It was noted that in the IME report, this encounter was not mentioned and there was no mention that the Veteran may have had recent reactivation of his TB at the time of his death. See Private Medical Opinion Addendum, P.C., M.D., December 14, 2012. Dr. P.C. again recounted that the Veteran presented to the ER on September 8, 2003, with complaints of a one-month history of hemoptysis, fever, chills, sweats and weight loss. A chest X-ray revealed mild blunting of the left costophrenic angle, which suggested a small pleural effusion. New strand opacity in the right lung base was concerning for infection. It was also noted that TB could not be ruled out. Vague slightly reticulonodular opacity was seen throughout the mid-right lung zone, which could have also been representative of infection. There was also progressive pleural thickening at the right apex as compared to the previous chest X-ray. Dr. P.C. stated that although the September 2003 attending radiologist went to the effort of adding the phrase, "tuberculosis cannot be excluded," the IME report omitted this phrase and stated that "...abnormalities were not at all typical of tuberculosis." Id. At the time of the Veteran's hospitalization and eventual death, his sputum and blood cultures were negative for mycobacterium, but as mentioned in the June 2012 medical opinion, Dr. P.C. stated that blood and sputum cultures are imperfect in detecting active mycobacterium infection. The IME report stated "[t]he patient died because an aggressive leukemia resulted in an immunocompromised state. The rapidity and pattern of the pneumonia is not at all typical of tuberculosis but rather suggests an opportunistic fungal, gram-negative or gram-positive bacterial infection of the lung and a probable fungal infection causing the mucositis." Review of the medical records revealed that the Veteran's blood and sputum cultures were indeed negative for these other pathogens as well. Id. The IME report also stated that the last positive mycobacterium TB isolated in culture occurred in May 1990 and the Veteran received two years of adequate triple therapy to cure this disease. As previously noted by Dr. P.C., culture results may not always be indicative of reactivation. The Veteran's presenting symptoms at the time of his June 2002 VA examination were considered highly suggestive of reactivated PTB. Additionally, it was noted that due to DNA mapping, it is becoming clear that patients previously treated for PTB may have reactivation of latent TB or reinfection or exogenous acquisition of new TB strains. (See Patients with previously treated tuberculosis no longer neglected, supra.) In fact, Dr. P.C. stated that in 2005, a study found that reinfection after successful treatment was more common than new TB infections. (See Rate of reinfection tuberculosis after successful treatment is higher than rate of new tuberculosis, supra.) Given the Veteran's symptoms and his history of living in the Philippines, Dr. P.C. concluded that it was at least as likely as not that his symptoms did indeed represent active infection, possibly with a strain different from that, which was treated in 1990. Id. As noted in the June 2012 private medical opinion, Dr. P.C. again concluded that the Veteran's chest X-rays at the time of his death were consistent with pulmonary leukemic infiltration and there was no debate as to the proximate cause of his death. However, it was Dr. P.C.'s opinion that the Veteran's service-connected PTB contributed to the disease process, which eventually caused his death. This conclusion was based upon the June 2002 VA examination findings, the Veteran's residence in a high burden TB environment such as the Philippines, and a review of the pertinent medical literature on the subject. Dr. P.C. disagreed with the IME conclusion that the Veteran was "cured" of PTB and that it did not accelerate or contribute to his death. Id. Analysis The Appellant in essence contends that that the Veteran's service-connected PTB contributed to the cause of his death. In order for service connection for the cause of the Veteran's death to be granted, three elements must be present: (1) evidence of death; (2) evidence of in-service incurrence of disease or injury and/or service-connected disability; and (3) medical nexus linking (1) and (2). Cf. Hickson v. West, 12 Vet. App. 247, 253 (1999). In this case, element (1) has obviously been met. The Veteran's death certificate has been obtained and associated with the VA claims file. Id. With respect to element (2), at the time of the Veteran's death service connection was in effect for PTB, evaluated as 30 percent disabling. Hickson element (2) is therefore met. Id. With respect to crucial element (3), nexus, there are conflicting medical opinions of record regarding the relationship between the Veteran's service-connected PTB and his fatal respiratory failure, due to leukemia. In the Appellant's favor are the June 2012 and December 2012 private medical opinions of Dr. P.C., which pertinently state that it is at least as likely as not that the Veteran's service-connected PTB contributed to the cause of his death. This opinion was based on a finding that the May 2004 addition of PTB to the Veteran's death certificate was proper, and that the negative cultures obtained during the last year of the Veteran's life were inaccurate, based upon his symptomatology. As such, it was determined that the Veteran suffered from reactivation of his PTB, which contributed to his death. See Private Medical Opinions, P.C., M.D., June 7, 2012 and December 14, 2012. Arguably against the Appellant's claim are the October 2004 VA medical opinion and the September 2012 IME report. The October 2004 VA medical opinion did not acknowledge that PTB had been added to the Veteran's death certificate in June 2004, and thus concluded that respiratory failure and leukemia were the causes of the Veteran's death. The VA physician relied on the 1990 findings of reactivation and treatment for the Veteran's PTB as the last evidence of active disease. As such, it was determined that the Veteran's service-connected PTB did not cause or contribute to cause his death. See VA Medical Opinion Report, October 1, 2004. The September 2012 IME report determined that the Veteran's service-connected PTB did not cause or contribute to cause his death because the testing performed in conjunction with the Veteran's treatment prior to his death (i.e. laboratory results) did not reveal a diagnosis of PTB. As such, it was determined that the Veteran's service-connected PTB did not cause or contribute to cause his death, nor did it accelerate the non-service connected conditions that ultimately caused his death. See IME Opinion, September 28, 2012. In adjudicating a claim, the Board is charged with the duty to assess the credibility and weight given to evidence. See Madden v. Gober, 125 F.3d 1477, 1481 (Fed. Cir. 1997), cert. denied, 523 U.S. 1046 (1998). Indeed, in Jefferson v. Principi, 271 F.3d 1072, 1076 (Fed. Cir. 2001), the United States Court of Appeals for the Federal Circuit, citing its decision in Madden, recognized that the Board had inherent fact-finding ability. The Board may appropriately favor the opinion of one competent medical authority over another. See Owens v. Brown, 7 Vet. App. 429, 433 (1995); Wensch v. Principi, 15 Vet. App. 362, 367 (2001). After reviewing the record, and for reasons stated immediately below, the Board finds the favorable opinion of Dr. P.C. to be of greater probative value than the opinions of the October 2004 VA examiner and the September 2012 IME report to the contrary. In his opinions, Dr. P.C. thoroughly reviewed the Veteran's medical records and clearly explained the symptomatology demonstrated by the Veteran, to include the X-ray findings during the June 2002 VA examination, which noted that TB could not be ruled out at that time. Thereafter, Dr. P.C. clearly supported his opinion that the Veteran suffered from PTB at the time of his death. He cited to specific medical authority in rendering his opinion, and explained in detail the possibility of misdiagnosis in cases such as the Veteran's. Further, Dr. P.C. was able to refute each of the conclusions rendered in the September 2012 IME report with reference to specific medical research in association with the Veteran's records. Whether a physician provides a basis for his or her medical opinion goes to the weight or credibility of the evidence in the adjudication of the merits. See Hernandez-Toyens v. West, 11 Vet. App. 379, 382 (1998). Here, the Board finds that Dr. P.C. provided a thorough and well-reasoned opinion in support of the Veteran's claim. As such, it is afforded great probative weight. As noted above, the October 2004 VA medical opinion failed to acknowledge the fact that PTB had been added to the Veteran's death certificate as a contributory cause to his death. The opinion focused only on respiratory failure and leukemia as the indicated causes of death. As this opinion did not take into account all of the relevant evidence, it is of little probative value. Id. With respect to the September 2012 IME report, the IME physician failed to acknowledge the Veteran's June 2002 VA examination report, which noted that (based on the X-ray evidence) TB could not be ruled out. Further, the IME physician failed to specifically address the symptoms the Veteran complained of upon admission to the hospital in September 2003, and question whether these symptoms were indicative of reactivated PTB. Furthermore, the IME physician's opinion was based entirely upon the negative laboratory testing results, revealing a negative sputum result, without addressing the medical literature that clearly notes that these results are never 100 percent accurate. The IME physician also did not account for the Veteran living most of his life in the Philippines and whether that location could affect his tuberculosis. In fact, the IME physician failed to reference any relevant medical literature in rendering his opinion. For all of the aforementioned reasons, the Board affords the IME report little probative value. See Nieves-Rodriguez v. Peake, 22 Vet. App. 295 (2008) [the probative value of a medical opinion comes from when it is the factually accurate, fully articulated, and sound reasoning for the conclusion, not the mere fact that the claims file was reviewed]. The Board accordingly finds that the most persuasive and competent evidence of record favors a finding that the Veteran's service-connected PTB contributed substantially or materially to the Veteran's death. Resolving all doubt in the Veteran's favor, the Board therefore concludes that element (3), nexus or relationship, is satisfied and a grant of service connection for the cause of the Veteran's death is warranted. ORDER Entitlement to service connection for the cause of the Veteran's death is granted. ____________________________________________ WAYNE M. BRAEUER Veterans Law Judge, Board of Veterans' Appeals Department of Veterans Affairs