Cutaneous low-grade marginal zone lymphoma; This literature case, derived from a full text article, was received on 27APR2022.   A 38-year-old male developed "cutaneous low-grade marginal zone lymphoma" (PT: Cutaneous lymphoma) following the administration of BioThrax (anthrax vaccine adsorbed) for immunization.  Case report: A 38-year-old male was referred to dermatology for a 1-cm tender pink nodule on his upper arm at the site of an anthrax vaccination administered 14 months prior. He reported that the nodule was preceded by "swelling the size of a baseball" at the anthrax vaccine injection site that developed after receiving the fifth dose of the vaccine series. He did not have a sustained reaction to the previous injections. The patient denied systemic symptoms including fever, weight loss, night sweats, or lymphadenopathy. His past medical and family history was unremarkable.  Due to persistence of the lesion, a skin biopsy was performed followed by excision. Histopathology revealed an unremarkable epidermis with a dense dermal lymphoid infiltrate without germinal center formation, predominantly composed of small to medium sized lymphocytes with abundant plasma cells that were perivascular, perifollicular and periadnexal in distribution. A CD3 immunostain highlighted a dense T cell infiltrate, while CD20 highlighted B cells in a nodular distribution. A CD138 immunostain highlighted numerous plasma cells, predominantly present at the periphery of the lymphoid infiltrate that were monoclonal with kappa-restriction by kappa and lambda immunostains. Peripheral blood counts were within normal limits and peripheral blood flow cytometry did not reveal any circulating lymphoma cells. In addition, Computerised tomogram (CT) chest/abdomen/pelvis did not reveal lymphadenopathy. Overall findings were consistent with a cutaneous low-grade marginal zone lymphoma. Solitary primary cutaneous marginal zone lymphomas were generally treated with local radiation therapy and/or excision. In this patient's case, definitive excision was performed, and radiation therapy was reserved in case of recurrence. The patient currently was asymptomatic and doing well.  Author's comment: This was the first case report of a lymphoma developing at the site of an anthrax vaccination. While, cutaneous pseudolymphoma was considered in this case, the presence of kappa-restricted plasma cells indicated a monoclonal proliferation consistent with extranodal marginal zone lymphoma (ENMZL). Given the patient's significant ongoing inflammatory response and nodule formation corresponding to the time frame of his vaccine administration, it was postulated that his Anthrax vaccination led to the development of his localized cutaneous lymphoma.  Company comment:   Despite the attribution of the lymphoma to the BioThrax vaccine, the cause cannot be proven. As it is known, the cause of T-cell cutaneous lymphoma, a form of non-Hodgkin lymphoma or any form of cancer is not known. It is not known why a cancer cell begins to mutate and multiply. Despite the attribution of cutaneous lymphoma to exogenous/endogenous agents like bacteria or hepatitis C including influenza and hepatitis vaccines, the attribution is vague. Our data shows that in more than 16.000.000 doses of BioThrax there have been no cases of cutaneous lymphoma. It is possible that the origin was caused by the initial induration at the vaccine site but not by the vaccine itself; however, the Company agrees with the reporter that the cutaneous lymphoma was possible related to BioThrax, complete exclusion of the cause is not possible. The case is considered serious due to medical significance of the event and the required intervention. Cutaneous lymphoma is unlisted as per USPI of BioThrax.; Sender's Comments: Despite the attribution of the lymphoma to the BioThrax vaccine, the cause cannot be proven. As it is known, the cause of T-cell cutaneous lymphoma, a form of non-Hodgkin lymphoma or any form of cancer is not known. It is not known why a cancer cell begins to mutate and multiply. Despite the attribution of cutaneous lymphoma to exogenous/endogenous agents like bacteria or hepatitis C including influenza and hepatitis vaccines, the attribution is vague. Our data shows that in more than 16.000.000 doses of BioThrax there have been no cases of cutaneous lymphoma. It is possible that the origin was caused by the initial induration at the vaccine site but not by the vaccine itself; however, the Company agrees with the reporter that the cutaneous lymphoma was possible related to BioThrax, complete exclusion of the cause is not possible. The case is considered serious due to medical significance of the event and the required intervention. Cutaneous lymphoma is unlisted as per RA of BioThrax.