Pathological and molecular analysis of a composite lymphoma of mantle cell lymphoma and Epstein-Barr virus-positive follicular lymphoma.

Composite lymphoma (CL) is a very rare clinical entity defined by the presence of two or more different subtypes of lymphoma in the same lymph node. We report a case of CL in a 78-year-old male presenting with leukocytosis and swelling of multiple lymph nodes. A left axillary node biopsy showed atypical lymphocytes in both the interfollicular and follicular areas. Immunohistochemistry revealed that mantle cell lymphoma (MCL) was mainly present in the interfollicular area and follicular lymphoma (FL) was present in the follicular area. Polymerase chain reaction analysis of immunoglobulin heavy chain gene rearrangements confirmed that they were clonally related neoplasms. However, Epstein-Barr virus (EBV) DNA was detected in only FL cells, suggesting that MCL and FL had split into two clones in the early steps of pathogenesis. This is the first reported case of CL with EBV-negative B-cell non-Hodgkin lymphoma (NHL) and EBV-positive B-cell NHL with a clonal relationship. We discuss the developmental processes of these two lymphomas.

Discordant lymphocyte-depleted classical Hodgkin's and peripheral T-cell lymphoma arising in a patient 11 years after diagnosis of multicentric Castleman's disease.

Castleman's disease (CD) is thought to be related with an initially benign viral disease with cytokine-driven propagation and malignant transformation. This paper reports the first case of a simultaneous discordant lymphoma consisting of lymphocyte-depleted classical Hodgkin's lymphoma (LDCHL) and peripheral T-cell lymphoma (PTCL) arising in a patient with multicentric CD (MCD). PTCL occurred 4 years after the diagnosis of MCD, and LDCHL was developed 6 years after the treatment of PTCL, sequentially. The following year, the patient presented with a relapse of a simultaneous discordant lymphoma. On excisional cervical LN biopsy, immunohistochemical stain pattern was identical with previously diagnosed LDCHL, which expressed CD30, CD15, PAX5, and Epstein-Barr virus (EBV)-encoded RNA. PTCL was positive for CD3, CD4, CD5, CD10, and CD56, and showed identical TCRB and TCRG gene rearrangements to those detected initially. MCD was thought to be the major contributing factor leading to initial PTCL, while EBV-positive LDCHL is thought to have promoted the development of PTCL, as a persistently abnormal immune microenvironment may induce the recurrence of PTCL. MCD runs a more aggressive course and can progress to Hodgkin's lymphoma (HL), non-Hodgkin's lymphoma (NHL), or combined HL/NHL. Due to its malignant potential, prompt recognition and therapy is critical for these situations, which may be life threatening.