# Uncommon Bedfellows: Coexistent T-Cell Large Granular Lymphocytic Leukaemia and Hodgkin Lymphoma—A Case Report

## TL;DR

A rare case of two blood cancers, Hodgkin lymphoma and T-cell large granular lymphocytic leukemia, occurring together in one patient is reported, highlighting unusual diagnostic and treatment challenges.

## Contribution

This case report documents the rare coexistence and evolution of Hodgkin lymphoma and T-LGLL, offering insights into their potential therapeutic interplay.

## Key findings

- A patient with Hodgkin lymphoma developed T-LGLL after treatment, suggesting therapy-induced clonal selection.
- Bone marrow analysis revealed biclonal T-cell populations at diagnosis, evolving to monoclonality over time.
- The case highlights the complexity of managing dual lymphoid neoplasms and the need for further research into their co-occurrence.

## Abstract

This case describes an exceptionally rare co-occurrence of Hodgkin lymphoma (HL) and T-cell large granular lymphocytic leukaemia (T-LGLL), highlighting the diagnostic and therapeutic complexity of dual lymphoid neoplasms. A 39-year-old African man presented with B symptoms and was diagnosed with stage IIIB HL and achieved remission following six cycles of doxorubicin (adriamycin), bleomycin, vinblastine and dacarbazine (ABVD) chemotherapy with external beam radiotherapy. At diagnosis, bone marrow evaluation revealed lymphocytosis with aberrant T-cell phenotypes and biclonality in the T-cell receptor rearrangements, suggestive of a coexistent clonal T-cell process. Following treatment, he developed persistent lymphocytosis with conversion to a monoclonal T-cell population, indicating clonal selection. Nearly 3 years later, the patient relapsed with HL, accompanied by bone marrow infiltration by large granular lymphocytes with a monoclonal, aberrant cytotoxic T-cell phenotype, consistent with T-LGLL. This case is notable for the evolution of T-LGLL in the context of relapsed HL, possibly due to therapy related selection of a pre-existing T-cell clone. Literature on the coexistence of HL and T-LGLL is sparse, underscoring the rarity of this presentation.