Composite follicular lymphoma and classic Hodgkin lymphoma

Double trouble: insights from a rare case of extranodal composite lymphoma in an elderly man, with comprehensive literature review

Composite lymphoma (CL) is a rare cancer characterized by the concurrent occurrence of more than one type of lymphoma within the same organ or tissue in an individual. Its occurrence at extranodal sites is exceptional, with only a few cases documented in the literature. A 62-year-old gentleman presented with dystonia, dysphagia, and irregular enlargement of the right tonsil for the last three months. Based on a clinical suspicion of tonsillar malignancy, tonsillectomy was done. The histopathologic examination revealed effacement of the architecture by large irregular lymphoid nodules with interfollicular expansion. The nodules showed sheets of small atypical lymphoid cells, while the interfollicular areas showed large atypical lymphoid cells with scattered typical binucleate Reed-Sternberg cells. Immunohistochemistry confirmed mantle cell lymphoma (MCL) in the nodules and classical HL (cHL) in the interfollicular areas. Based on these features, a diagnosis of composite MCL with cHL was rendered. He was treated with bendamustine and rituximab chemotherapy and remained in complete remission for five years when he presented with significant right-sided neck swelling. Percutaneous fine needle aspiration and subsequent flow cytometry confirmed a relapse of the MCL component of the CL. The index report documents an exceptional case of CL, comprising MCL and cHL, presenting at an uncommon extranodal site. In addition, it also emphasizes the importance of adequate sampling and the simultaneous use of immunochemistry and/or flow cytometry to confirm the presence of more than a single type of lymphoma, which may be easily overlooked on microscopy alone.

T cell lymphoma and secondary primary malignancy risk after commercial CAR T cell therapy

We report a T cell lymphoma (TCL) occurring 3 months after anti-CD19 chimeric antigen receptor (CAR) T cell immunotherapy for non-Hodgkin B cell lymphoma. The TCL was diagnosed from a thoracic lymph node upon surgery for lung cancer. The TCL exhibited CD8+ cytotoxic phenotype and a JAK3 variant, while the CAR transgene was very low. The T cell clone was identified at low levels in the blood before CAR T infusion and in lung cancer. To assess the overall risk of secondary primary malignancy after commercial CAR T (CD19, BCMA), we analyzed 449 patients treated at the University of Pennsylvania. At a median follow-up of 10.3 months, 16 patients (3.6%) had a secondary primary malignancy. The median onset time was 26.4 and 9.7 months for solid and hematological malignancies, respectively. The projected 5-year cumulative incidence is 15.2% for solid and 2.3% for hematological malignancies. Overall, one case of TCL was observed, suggesting a low risk of TCL after CAR T.

Composite Lymphoma with Follicular Lymphoma Transformation to Clonally Related Epstein-Barr Virus (EBV) Positive Diffuse Large B-Cell Lymphoma and EBV-PositiveClassic Hodgkin Lymphoma

While the Epstein-Barr virus (EBV) is known to drive de novo lymphomagenesis, it may rarely contribute to transformation of indolent lymphoma as well. Some EBV-related lymphomas represent a diagnostic challenge with important prognostic and therapeutic implications. We describe a case of follicular lymphoma (FL) transformation to both EBV + diffuse large B-cell lymphoma (DLBCL) and EBV + classic Hodgkin lymphoma (cHL), the latter of which was only identified retrospectively after selective outgrowth during DLBCL therapy. Finally, we describe successful salvage therapy with brentuximab vedotin plus nivolumab. This is the first known case of composite lymphoma with FL, EBV + DLBCL, and EBV + cHL within a single lymph node. The disease course highlights the importance of careful morphologic examination and comprehensive immunophenotypic characterization of EBV + lymphomas to ensure proper clinical care and underscores the potential for novel therapies currently under investigation. This trial is registered with NCT01671813.

Plasticity in Classical Hodgkin Composite Lymphomas: A Systematic Review

The co-occurrence of several lymphomas in a patient defines composite/synchronous lymphoma. A common cellular origin has been reported for both contingents of such entities. In the present review, we aimed to gather the available data on composite lymphomas associating a classical Hodgkin lymphoma (cHL) with another lymphoma, to better understand the plasticity of mature B and T-cells. This review highlights that >70% of patients with a composite lymphoma are ≥55 years old, with a male predominance. The most reported associations are cHL with follicular lymphoma or diffuse large B-cell lymphoma, with over 130 cases reported. The cHL contingent is often of mixed cellularity type, with a more frequent focal/weak CD20 expression (30% to 55.6%) compared to de novo cHL, suggesting a particular pathophysiology. Moreover, Hodgkin cells may express specific markers of the associated lymphoma (e.g., BCL2/BCL6 for follicular lymphoma and Cyclin D1 for mantle cell lymphoma), sometimes combined with common BCL2/BCL6 or CCND1 rearrangements, respectively. In addition, both contingents may share similar IgH/IgK rearrangements and identical pathogenic variants, reinforcing the hypothesis of a common clonal origin. Finally, cHL appears to be endowed with a greater plasticity than previously thought, supporting a common clonal origin and a transdifferentiation process during lymphomagenesis of composite lymphomas.