Citation Nr: 9901537 Decision Date: 01/21/99 Archive Date: 02/01/99 DOCKET NO. 94-28 729 ) DATE ) ) On appeal from the Department of Veterans Affairs Regional Office in Huntington, West Virginia THE ISSUE Entitlement to service connection for hairy-cell leukemia, secondary to Agent Orange exposure in service. REPRESENTATION Appellant represented by: Richard P. Cohen, attorney at law WITNESS AT HEARING ON APPEAL Appellant ATTORNEY FOR THE BOARD D. P. Havelka, Associate Counsel INTRODUCTION The veteran’s active military service extended from February 1968 to February 1970. This matter comes before the Board of Veterans’ Appeals (Board) on appeal from an April 1994 rating decision by the Department of Veterans Affairs (VA) Regional Office (RO) in Huntington, West Virginia. That rating decision denied the veteran’s claim for entitlement to service connection for a hairy cell leukemia and a skin disorder, secondary to Agent Orange exposure in service. In January 1997 the Board upheld the denial, and the veteran appealed the Board's decision to the United States Court of Veterans Appeals (Court). In September 1997, counsel for the appellant and the Secretary filed a “Joint Motion for Remand and to Stay Further Proceedings,” pending a ruling on the motion. An Order of the Court dated in September 1997 granted the motion for remand and vacated the Board’s decision dated January 31, 1997 with respect to denying the veteran’s claim for service connection for hairy-cell leukemia, secondary to Agent Orange exposure in service. The case was remanded for further development, readjudication, and disposition in accordance with the Court’s order. [redacted]. Specifically, the case was remanded to obtain VA medical records. The required development has been completed. In December 1996, a hearing was held before Bettina S. Callaway, who is the Board member making this decision and who was designated by the Chairman to conduct that hearing, pursuant to 38 U.S.C.A. § 7102(b) (West 1991). FINDINGS OF FACT 1. The RO has obtained all relevant evidence necessary for an equitable disposition of the veteran’s appeal. 2. The veteran had active military service in the Republic of Vietnam during the Vietnam Era. 3. The service medical records do not show any diagnosis of hairy cell leukemia, during service or within the first year after separation from service. 4. The medical evidence subsequent to active service reveals diagnoses of hairy cell leukemia and vasculitis. 5. There is no credible medical evidence showing that the veteran has non-Hodgkin’s lymphoma. 6. Hairy cell leukemia was not present in service or manifested in the first post service year, and is not shown to be due to exposure to Agent Orange. CONCLUSION OF LAW Hairy cell leukemia was not incurred in, or aggravated by, active military service and may not be presumed to have been incurred in service. 38 U.S.C.A. §§ 101(16), 1101, 1110, 1112, 1137 (West 1991); 38 C.F.R. §§ 3.303, 3.307, 3.309 (1998). REASONS AND BASES FOR FINDINGS AND CONCLUSION The veteran contends that the RO committed error in denying service connection for hairy cell leukemia, secondary to Agent Orange exposure in service. He argues that he was exposed to Agent Orange during his service in Vietnam and. as a result of this exposure, he developed hairy cell leukemia. Generally, service connection may be granted for a disability resulting from disease or injury incurred in or aggravated by active military service. 38 U.S.C.A. §§ 101(16), 1110 (West 1991). In addition, service connection may be granted for any disease diagnosed after discharge, when all the evidence including that pertinent to service, establishes that the disease was incurred in service. 38 C.F.R. § 3.303(d) (1995). The law provides that “a person who submits a claim for benefits under a law administered by the Secretary shall have the burden of submitting evidence sufficient to justify a belief by a fair and impartial individual that the claim is well grounded.” 38 U.S.C.A. § 5107(a) (West 1991). Establishing a well grounded claim for service connection for a particular disability requires more than an allegation that the disability had its onset in service or is service-connected; it requires evidence relevant to the requirements for service connection and of sufficient weight to make the claim plausible and capable of substantiation. See Franko v. Brown, 4 Vet. App. 502, 505 (1993); Tirpak v. Derwinski, 2 Vet. App. 609, 610 (1992); Murphy v. Derwinski, 1 Vet. App. 78, 81 (1990). The three elements of a “well grounded” claim are: (1) evidence of a current disability as provided by a medical diagnosis; (2) evidence of incurrence or aggravation of a disease or injury in service as provided by either lay or medical evidence, as the situation dictates; and (3) a nexus, or link, between the inservice disease or injury and the current disability as provided by competent medical evidence. See Caluza v. Brown, 7 Vet. App. 498, 506 (1995), aff’d per curiam, 78 F.3d 604 (Fed. Cir. 1996); see also 38 U.S.C.A. § 1110 (West 1991); 38 C.F.R. § 3.303 (1998). The veteran has a current disability and a medical opinion which relates this disability to exposure to Agent Orange during his military service. For the purpose of determining whether a claim is well-grounded, the evidence in support of the claim is presumed credible. Justus v. Brown, 5 Vet. App. 19 (1993). Thus, the claim is well-grounded. Certain chronic diseases, including malignant tumors, cancer, may be presumed to have been incurred during active military service if manifest to a degree of 10 percent within the first year following active service. 38 U.S.C.A. §§ 1101, 1112, 1137 (West 1991); 38 C.F.R. §§ 3.307, 3.309 (1998). VA regulations provide that, if a veteran was exposed to an herbicide agent during active service, presumptive service connection is warranted for the following disorders: chloracne or other acneform disease consistent with chloracne; Hodgkin’s disease; multiple myeloma; Non-Hodgkin’s lymphoma; acute and subacute peripheral neuropathy; porphyria cutanea tarda; prostate cancer; respiratory cancers (cancer of the lung, bronchus, larynx, or trachea); and, soft-tissue sarcoma (other than osteosarcoma, chondrosarcoma, Kaposi’s sarcoma, or mesothelioma). Presumptive service connection for these disorders as a result of Agent Orange exposure is warranted if the requirements of Sec. 3.307(a)(6) are met. 38 C.F.R. § 3.309(e) (1998). In the case of an Agent Orange related claim, when a veteran served in the Republic of Vietnam during the Vietnam era, competent medical evidence of the existence of a current presumptive disease with an open-ended presumptive period of time for service connection is sufficient to render the claim for service connection for the presumptive disease well- grounded. Brock v. Brown, 10 Vet. App. 155, 162 (1997). Put another way, “where 38 U.S.C. § 1116 and 38 C.F.R. §§ 3.307(d) and 3.309(e) are satisfied, the requirements for evidence of both service incurrence and causal nexus are satisfied.” Darby v. Brown, 10 Vet. App. 243, 246 (1997); Brock v. Brown, 10 Vet. App. 155, 162 (1997). The governing regulations also provide that a “veteran who, during active military, naval, or air service, served in the Republic of Vietnam during the period beginning on January 9, 1962, and ending on May 7, 1975 and has a disease listed at Sec. 3.309(e) shall be presumed to have been exposed during such service to an herbicide agent, unless there is affirmative evidence to establish that the veteran was not exposed to any such agent during that service.” 38 C.F.R. § 3.307(a)(6)(iii) (1998) (emphasis added). If the rebuttable presumptions of 38 C.F.R. § 3.307(d) (1995) are also not satisfied, then the veteran’s claim shall fail. The Secretary of the Department of Veterans Affairs has determined that a presumption of service connection based on exposure to herbicides used in the Republic of Vietnam during the Vietnam era is not warranted for any condition for which the Secretary has not specifically determined a presumption of service connection is warranted. See Notice, 61 Fed.Reg. 41442 (1996). A review of the veteran’s discharge papers, DD 214, reveals that he served in the Republic of Vietnam during the Vietnam era. The veteran’s service medical reports are of record and they appear to be complete. The service medical records contain entrance and separation examination reports and treatment records covering the intervening period of time. There is no indication in any of the service medical records that the veteran had any complaints, or diagnosis of leukemia. A large volume of medical evidence, both private and VA, has been obtained by the RO. The overwhelming weight of the medical evidence of record reveals that the veteran was diagnosed with hairy cell leukemia in 1990. The medical evidence of record reveals that the veteran was diagnosed with hairy cell leukemia in April 1990. In December 1996 the veteran presented sworn testimony at a hearing before the undersigned Member of the Board. The veteran testified that he was first diagnosed with hairy cell leukemia in April 1990. The veteran separated from active service in June 1970. He was first diagnosed with hairy cell leukemia in April 1990, almost two decades after he separated from active service, and well beyond the one-year period during which presumptive service connection is warranted. Therefore the preponderance of the evidence is against a grant of service connection for the veteran’s hairy cell leukemia on the basis of having been incurred during service or presumed to have been incurred in service because of being shown to a degree of 10 percent within a year of separation from service. However, the veteran does not claim that his leukemia was shown during service or during the first postservice year. He claims that service connection is warranted based on the fact that he served in Vietnam during the requisite period and that his disease, hairy cell leukemia, is or should be one of the diseases that, if shown following such service, is presumed to have been caused by Agent Orange. The veteran has submitted private medical evidence from several sources to support his claim. In April 1990 the veteran was hospitalized by a private physician; bone marrow and skin biopsies were conducted. The resulting May 1990 skin pathology report reveals a final pathological diagnosis of subacute spongiotic dermatitis, nonspecific chronic inflammation, and mild fat necrosis and fibrosis. The hospital discharge summary was dictated in June 1990 by Rogelio Lim, M.D. The final diagnosis was hairy cell leukemia and vasculitis. A June 1990 notation from a Dr. Parsons reveals that the veteran “called today wanting to know what the chemical cause for hairy cell leukemia was. I told him that the etiology of this was not known and this is according to the latest information I have in Cecil’s Textbook of Medicine. He indicated that he had called the American Cancer Society and they told him it was due to an environmental agent and I asked him if they gave him any more information that that and he said no. I advised him that as far as physicians are concerned we do not know the cause of hairy cell leukemia.” The veteran was sent to The Cleveland Clinic for confirmation of the diagnosis. A July 1991 letter from The Cleveland Clinic states that the veteran “has a diagnosis of hairy cell leukemia with vasculitic skin rash secondary to the above lymphoproliferative disorder.” The letter goes on to say that “Non-Hodgkin’s lymphoma is the diagnosis for which compensation may be derived. Hairy cell leukemia is a variant of the non-Hodgkin’s lymphoma group. Perse [sic] it is a different diagnosis, however, it is very similar to this family of disorders.” A September 1993 letter from Dr. Lim states that the veteran’s diagnosis is “Hairy Cell leukemia and Vasculitis. I feel that this condition was probably caused by [the veteran’s] exposure to Agent Orange.” The diagnosis “has been confirmed by Cleveland Clinic.” However, in October 1993 Dr. Lim submitted another letter which was almost identical to the September letter but with key differences. This time Dr. Lim stated that the veteran’s “diagnosis is Non-Hodgkin’s Lymphoma and Vasculitis. I feel that this condition was caused by [the veteran’s] exposure to Agent Orange.” Dr. Lim again stated that the veteran’s diagnosis “has been confirmed by Cleveland Clinic.” This one letter is the only evidence of record which reveals a diagnosis of non-Hodgkin’s lymphoma. The October 1993 letter submitted by Dr. Lim is highly questionable. The letter states that the veteran’s “diagnosis is Non-Hodgkin’s Lymphoma and Vasculitis. I feel that this condition was caused by [the veteran’s] exposure to Agent Orange.” Dr. Lim also stated that the veteran’s diagnosis “has been confirmed by Cleveland Clinic.” The Board finds this letter, and the opinions expressed in it to not be credible. Specifically, Dr. Lim stated that the veteran was diagnosed with non-Hodgkin’s lymphoma and that this diagnosis was confirmed by the Cleveland Clinic. In all of the medical evidence submitted from the Cleveland Clinic there has never been a diagnosis of non-Hodgkin’s Lymphoma. Dr. Lim's letter is the only evidence of record which shows a diagnosis of lymphoma as opposed to leukemia. This diagnosis, and the claim of confirmation, is also specifically contradicted by a November 1993 letter from the Cleveland Clinic which confirms only the diagnosis of hairy cell leukemia. The overwhelming weight of the medical evidence of record reveals that the veteran has hairy cell leukemia which has been verified by the Cleveland Clinic; Dr. Shah, a private oncologist; and by the oncology department at VAMC Huntington. The Board concludes that Dr. Lim may have considered an alternate diagnosis of the veteran’s cancer from hairy cell leukemia, a disease for which presumptive service connection on the basis of Agent Orange exposure is not warranted, to non-Hodgkin’s lymphoma, a disease which does warrant such a presumption, to advance his patient’s disability claim. As such, the Board finds that Dr. Lim's opinion that the veteran has non-Hodgkin's lymphoma lacks credibility, and the proper diagnosis is hairy cell leukemia. As we noted above, the following diseases warrant presumptive service connection on the basis of Agent Orange exposure during active service: chloracne or other acneform diseases consistent with chloracne, Hodgkin’s disease, multiple myeloma, non-Hodgkin’s lymphoma, acute and subacute peripheral neuropathy, porphyria cutanea tarda, prostate cancer, respiratory cancers, and soft-tissue sarcomas. 38 C.F.R. § 3.309(e) (1998). The record shows that the veteran has hairy cell leukemia, which is not one of the diseases listed above warranting a presumption of service incurrence if shown following the requisite service in Vietnam. The regulations provide that, if the veteran has the requisite Vietnam service and has one of the diseases on the list, then it is presumed that the disease resulted from exposure to Agent Orange. The Board notes that the veteran’s discharge papers, DD 214, reveal that he had approximately 3 months and 16 days of service in Vietnam during the Vietnam era. However, although the veteran served in Vietnam during the Vietnam era, he does not have one of the diseases specified in 38 C.F.R. § 3.309(e). As such, he is not presumed to have been exposed to Agent Orange during service. 38 C.F.R. § 3.307(a)(6)(iii) (1998). Notwithstanding the foregoing with respect to presumptive service connection for Agent Orange exposure, the United States Court of Appeals for the Federal Circuit has determined that the Veterans’ Dioxin and Radiation Exposure Compensation Standards (Radiation Compensation) Act, Pub. L. No. 98-542, § 5, 98 Stat. 2724, 2727- 29 (1984), does not preclude a veteran from establishing service connection with proof of actual direct causation. Combee v. Brown, 34 F.3d 1039 (Fed.Cir. 1994). The Board has determined that the leukemia was not shown until 1990, so, in order to prevail, the veteran must show that it developed years after service as a result of some incident of service. In this instance, the veteran claims that it is due to Agent Orange exposure. The record does not show that the veteran was exposed to Agent Orange during his short period of service in Vietnam and, because leukemia is not a disease which warrants the presumption of being due to Agent Orange exposure in Vietnam, there is no presumption that he was, in fact, exposed to Agent Orange. The Board believes that the veteran's claims are, in effect, that (1) hairy cell leukemia is due to exposure to Agent Orange (with the underlying assumption that such exposure must have been in Vietnam) or (2) that hairy cell leukemia is basically the same disease as non-Hodgkin's lymphoma and to extend the presumption to non-Hodgkin's lymphoma is tantamount to extending the presumption to hairy cell leukemia. A June 1990 notation from a Dr. Parsons reveals that the veteran “called today wanting to know what the chemical cause for hairy cell leukemia was. I told him that the etiology of this was not known and this is according to the latest information I have in Cecil’s Textbook of Medicine. He indicated that he had called the American Cancer Society and they told him it was due to an environmental agent and I asked him if they gave him any more information that that and he said no. I advised him that as far as physicians are concerned we do not know the cause of hairy cell leukemia.” The veteran was sent to The Cleveland Clinic for confirmation of the diagnosis. A July 1991 letter from The Cleveland Clinic states that the veteran “has a diagnosis of hairy cell leukemia with vasculitic skin rash secondary to the above lymphoproliferative disorder.” The letter goes on to say that “Non-Hodgkin’s lymphoma is the diagnosis for which compensation may be derived. Hairy cell leukemia is a variant of the non-Hodgkin’s lymphoma group. Perse [sic] it is a different diagnosis, however, it is very similar to this family of disorders.” (emphasis added). A September 1993 letter from Dr. Lim states that the veteran’s diagnosis is “Hairy Cell leukemia and Vasculitis. I feel that this condition was probably caused by [the veteran’s] exposure to Agent Orange.” The diagnosis “has been confirmed by Cleveland Clinic.” However, in October 1993 Dr. Lim submitted another letter which was almost identical to the September letter but with key differences. This time Dr. Lim stated that the veteran’s “diagnosis is Non-Hodgkin’s Lymphoma and Vasculitis. I feel that this condition was caused by [the veteran’s] exposure to Agent Orange.” Dr. Lim again stated that the veteran’s diagnosis “has been confirmed by Cleveland Clinic.” In February 1997 Dr. Lim submitted another letter on the veteran’s behalf. The letter states that the veteran “has been a patient of mine since 1990, when he was diagnosed with hairy cell leukemia. Hairy cell leukemia is a B-cell neoplasm related to non-Hodgkin’s lymphoma and chronic lymphocytic leukemia. Exposure to Agent Orange is the probable cause in the development of [the veteran’s] hairy cell leukemia.” Dr. Lim provides no scientific basis for his proposition that Agent Orange probably caused the veteran's leukemia. In addition, if he reached this conclusion because he found the veteran had been exposed to Agent Orange, which probably caused leukemia because there is no other likely cause, the Board notes that there is no evidence that the veteran was, indeed, exposed to Agent Orange, and the presumption of Agent Orange exposure is not applicable because he does not have a disease which warrants the presumption. As noted above, the Board found the October 1993 letter submitted by Dr. Lim is highly questionable. It appears that Dr. Lim may have considered an alternate diagnosis of the veteran’s cancer from hairy cell leukemia, a disease for which presumptive service connection on the basis of Agent Orange exposure is not warranted, to non-Hodgkin’s lymphoma, a disease which does warrant such a presumption, to advance his patient’s disability claim. As such, the Board finds the medical opinions expressed by Dr. Lim to lack credibility. A November 1993 letter from the Cleveland Clinic states that the veteran “has been evaluated at the Cleveland Clinic and found to have hairy cell leukemia. Hairy cell leukemia is a B-cell neoplasm akin to non-Hodgkin’s lymphoma and chronic lymphocytic leukemia. It is an entity all unto itself; however aspects of causation are similar for all three illnesses. I would consider Agent Orange exposure as etiologic in the development of [the veteran’s] hairy cell leukemia.” The Board notes that there is no medical data submitted in support of this opinion regarding causation. An April 1996 letter from Arvind B. Shah, M.D., a private oncologist, states that the veteran “was diagnosed with Hairy Cell Leukemia in 5/90. He is now stable and on a yearly follow-up with routine lab work every three month[s].” In November 1998 the veteran’s attorney submitted a photocopy of a 1985 medical journal article which found an “association between hairy cell leukemia and exposure to organic chemicals” in the farming and woodworking occupations. In September 1998 a VA examination of the veteran was conducted. The examining physician reviewed the veteran’s medical history and all of the medical evidence of record. The diagnosis was hairy cell leukemia. The examining physician provided the following discussion in his examination report: In the strictest sinse (sic), hairy cell leukemia is not classified as a non-Hodgkin’s lymphoma, though by definition it literally is non-Hodgkin’s lymphoma in the sense that it is a B cell dyscrasia, a neoplasm of the B cells just as certain other non-Hodgkin’s lymphoma. It has enough differences biochemically with surface markers and products produced, that it is not classed as a non-Hodgkin’s lymphoma. . . . (Hairy cell leukemia) and (chronic lymphocytic leukemia) are separate disease entities whereas non-Hodgkin’s lymphoma is an umbrella covering several of the B cell dyscrasias. Again, each of these have their own particular characteristics, but they are so closely interlinked that most anyone would tend to feel that what causes one may cause another. I think this is what the Cleveland Clinic based their statements on at that time they rendered their opinion that they would feel hairy cell is likely secondary to herbicide exposure, not so much based on the preponderance of medical evidence, but rather along the lines of thinking such as “it would follow that . . .", basically if you are going to include non-Hodgkin’s then this would have to have the same etiology . . . is the type of thinking that has rendered statement in support and including hairy cell, again rather than based on actual hard core medical data. Further, I think in consideration for his age at the onset, generally the median age of onset is around 50 for hairy cell and around 60 for chronic lymphocytic leukemia. He developed his hairy cell at an early age of 40 to 41. It is already 4 to 1 more common in men than women, so that was in and of itself not an anomaly. There is not data that has suggested a presumptive development; rather the only argument being that of causal relation to Agent Orange exposure, “piggyback” to that body of evidence that links non-Hodgkin’s with prior Agent Orange exposure. Again the thinking is more along the lines of “gee, they are so closely related, if non- Hodgkin’s has been shown to have an association then certainly this one would too, or it would stand to reason that this one would too.” The etiologic agents of all three illnesses are uncertain even to date. Going against him and ruling in his favor is that VA has determined that leukemia is a disability which has been specifically determined not to warrant service connection on the basis of Agent Orange exposure. Also, an NAS report noted in the file from 1993 was evaluating herbicide exposure with subsequent development of leukemias in studies of farmers in Italy and they found the incidence of leukemia was not elevated in this group. In 1996 the NAS revealed seven new studies, six of which showed no associated [sic] between the two. . . . To answer the questions specifically, the veteran’s hairy cell leukemia is not a form of non-Hodgkin’s lymphoma. It is not a variant of non-Hodgkin’s lymphoma, but these are all semantics. . . . I would like to note again that I have no studies to offer, nor does Cleveland Clinic have studies to offer that would show an association or medical documentation of herbicide exposure and hairy cell leukemia. We are making a statement that given his young age and given the similarities between certain of the non-Hodgkin’s lymphomas and hairy cell, that if it causes one it likely would cause the other. This is not a statement that we would make if they were clinically distinct entities with few similarities, if the age of onset were a typical age of onset or if the etiology were known or felt to be more associated with genetic factors or otherwise, all of which do not apply in this setting. The October 1998 VA examination report echoes the opinions expressed by the Cleveland clinic. However, the VA oncologist admitted that the medical opinion that the veteran’s hairy cell leukemia was related to Agent Orange exposure was not based on hard medical evidence but was “piggybacked” on the regulatory presumptions accorded non- Hodgkin’s lymphoma and Agent Orange exposure. The VA physician also admitted that there was a large volume of medical evidence in the form of medical studies which showed no causal relationship between herbicide exposure and the development of leukemia. VA has entered into an agreement with the National Academy of Sciences (NAS) to review and summarize the scientific evidence concerning the association between exposure to herbicides used in support of military operations in the Republic of Vietnam during the Vietnam era and each disease suspected to be associated with such exposure. NAS submits reports on these activities every two years. Whenever VA determines, based on sound medical and scientific evidence, that a positive association (i.e., the credible evidence for the association is equal to or outweighs the credible evidence against the association) exists between exposure of humans to an herbicide agent (i.e., a chemical in an herbicide used in support of the United States and allied military operations in the Republic of Vietnam during the Vietnam era) and a disease, regulations are published establishing presumptive service connection for that disease. If the Secretary determines that a presumption of service connection is not warranted, he is to publish a notice of that determination, including an explanation of the scientific basis for that determination. The Secretary’s determination is based on consideration of the NAS reports and all other sound medical and scientific information and analysis available to the Secretary. See Notice, 61 Fed.Reg. at 41442 (1996). NAS, in its 1993 report, found that the potential evidence for an association between herbicide exposure and leukemia came from studies of farmers and residents of Seveso, Italy. When farmers were stratified by suspected herbicide exposure, the incidence of leukemia was generally not elevated, and in some cases elevation appeared to be due to factors other than herbicide exposure. Those studies generally did not adequately control for other significant confounding exposures. The suggestive evidence of increased risk concerning Seveso, Italy, was not significant because of the small number of actual cases in which leukemia was found. (See 59 FR 343-44 for study citations.) In its 1996 report, NAS reviewed seven new studies (Kogevinas et al., 1993; Asp et al., 1994; Blair et al., 1993; Bertazzi et al., 1993; Visintainer et al., 1995; Semenciw R.M., Morrison H.I., Morrison D., Mao Y., 1994. Leukemia mortality and farming in the prairie provinces of Canada. Canadian Journal of Public Health 85:208-211; and Dean G., 1994. Deaths agricultural workers in the Republic of Ireland. Journal of [??] in Epidemiology and Community Health 48:364-368). Six of these studies showed no association between herbicide exposure and leukemia or a nonsignificant elevated risk. Blair et al. (1993), a mortality study of farmers, showed a significantly increased PCMR for leukemia. The Blair study, however, did not correlate the increased PCMR to suspected herbicide exposure and did not control for other confounding factors. Accordingly, the Secretary has found that the credible evidence against an association between leukemia and herbicide exposure outweighs the credible evidence for such an association, and he has determined that a positive association does not exist. See Notice, 61 Fed.Reg. at 41445 (1996). The veteran has submitted medical opinions that relate his hairy cell leukemia to Agent Orange exposure during active service. However, these opinions do not appear to be based on scientific evidence showing that exposure to this particular environmental substance, Agent Orange, has been shown to cause hairy cell leukemia. Rather, when viewed in their entirety, these opinions tend to express the sentiment that, if VA has determined that non-Hodgkin's lymphoma warrants the presumption, then it would logically follow that hairy cell leukemia should also warrant the presumption, taking into account the similarities of the nature of the two diseases. However, the Secretary of VA, by regulation, determined which diseases warranted the presumption, and leukemia, after a review and consideration of the medical and scientific evidence, was specifically excluded from the list of diseases entitled to the presumption. 61 Fed.Reg. 41442- 49 (1996). As such, the preponderance of the evidence is against service connection for hairy cell leukemia, secondary to Agent Orange exposure in service. In November 1996 the veteran submitted a copy of a prior Board decision, docket number 91-47 197. This decision granted service connection for hairy cell leukemia due to exposure to Agent Orange and multiple toxic chemicals. This decision based the grant of service connection on “reasonable doubt” between conflicting medical opinions. The veteran’s assertion is that such reasoning should be applied in his case. In this regard, we note that decisions by the Board are not precedential in nature. Although the Board strives for consistency in issuing its decisions, previously issued Board decisions will be considered binding only with regard to the specific case decided. 38 C.F.R. § 20.1301 (1998). Moreover, the prior Board decision specifically found “a reasonable probability that the veteran was exposed to multiple toxic chemicals and to herbicides in service . . . and that there are medical opinions to the effect that that exposure caused the veteran’s hairy cell leukemia . . . ." (emphasis added). This decision did not specifically relate the leukemia only to Agent Orange, but also to various toxic chemicals. Again, we note that “the Secretary has found that the credible evidence against an association between leukemia and herbicide exposure outweighs the credible evidence for such an association, and he has determined that a positive association does not exist.” See Notice, 61 Fed.Reg. at 41445 (1996). ORDER Service connection for hairy cell leukemia is denied. BETTINA S. CALLAWAY Member, Board of Veterans’ Appeals NOTICE OF APPELLATE RIGHTS: Under 38 U.S.C.A. § 7266 (West 1991 & Supp. 1998), a decision of the Board of Veterans’ Appeals granting less than the complete benefit, or benefits, sought on appeal is appealable to the United States Court of Veterans Appeals within 120 days from the date of mailing of notice of the decision, provided that a Notice of Disagreement concerning an issue which was before the Board was filed with the agency of original jurisdiction on or after November 18, 1988. Veterans’ Judicial Review Act, Pub. L. No. 100-687, § 402, 102 Stat. 4105, 4122 (1988). The date which appears on the face of this decision constitutes the date of mailing and the copy of this decision which you have received is your notice of the action taken on your appeal by the Board of Veterans’ Appeals. - 2 -