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

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.