EBV‐positive low‐grade marginal zone lymphoma in the breast with massive amyloid deposition arising in a heart transplant patient: A report of an unusual case

According to the 2008 World Health Organization classification, low‐grade lymphomas arising in transplant recipients are not considered as specific types of PTLD. Most such cases are not associated with EBV infections, although rare reports of post‐transplant marginal zone lymphoma have been described. We describe the case of an 18‐yr‐old female with history of heart transplant who developed a breast mass, but was otherwise completely asymptomatic. Surgical excision of the mass and histopathologic examination showed a low‐grade B‐cell lymphoma most consistent with marginal zone lymphoma with massive amyloid deposition; furthermore, numerous tumor cells were positive for EBV by in situ hybridization for EBV‐encoded RNA. The patient was treated with reduction in immunosuppression, and no additional lesions developed. This case describes an atypical presentation of post‐transplant low‐grade B‐cell lymphoma, unusual in its location, histopathologic features, and association with EBV, thereby adding to the rare previous accounts of such an entity, suggesting the need to include post‐transplant marginal zone lymphomas in the current classification of PTLD, and helping in determining the optimal treatment modalities for such tumors.