Multiple pulmonary mucosa-associated lymphoid tissue lymphomas after living donor liver transplantation

Epstein-Barr Virus-negative Marginal Zone Lymphoma as an Uncommon Form of Monomorphic Posttransplant Lymphoproliferative Disorder

Monomorphic posttransplant lymphoproliferative disorders have been defined as lymphoid or plasmacytic proliferations that fulfill criteria for one of the B-cell or T/NK-cell neoplasms recognized in immunocompetent hosts in the current WHO Classification. Low-grade B-cell neoplasms have historically been excluded from this category, although rare reports of marginal zone lymphoma (MZL) have been described. We report 9 cases of posttransplant Epstein-Barr virus-negative MZL, all arising in solid organ transplant recipients (4 renal, 3 liver, 1 cardiac, and 1 liver, pancreas, and small bowel). Seven were extranodal MZL of mucosa-associated lymphoid tissue type, all of which had gastrointestinal involvement (4 colon, 1 duodenum, 1 stomach, and 1 oropharynx/base of tongue). Notably, the preferential involvement of intestine distinguishes posttransplant extranodal MZL from sporadic cases. Immunoglobulin light-chain restriction was seen in all cases, with polymerase chain reaction showing a monoclonal pattern in 7 of 8 cases with successful amplification of polymerase chain reaction products. A clonally unrelated recurrence was seen in one case. Next-generation sequencing identified recurrent mutations previously reported in MZL in 3/5 cases. MZL was diagnosed at least 1 year after solid organ transplant (median time to presentation, 84 mo; range, 13 to 108 mo). The median age was 44 (range, 9 to 73 y); the male: female ratio was 5:4. The mean follow-up was 33.4 months, with an indolent clinical course observed. A subset responded to reduction in immunosuppression and anti-CD20 therapy alone. These data support the designation of Epstein-Barr virus-negative MZL as an uncommon form of monomorphic posttransplant lymphoproliferative disorders.

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.