Gamma heavy chain disease associated with large granular lymphocytic leukemia: A report of two cases and review of the literature.

Objective and Importance: Gamma heavy chain diseases (γHCD) and large granular lymphocyte (LGL) leukemia are two rare lymphoproliferative diseases, respectively with B and T phenotype. Both γHCD and LGL leukemia share some similar clinical features, such as cytopenias, splenomegaly, and recurrent infections. Association of these two diseases is exceptional and suggest pathogenic link. We report two cases of γHCD associated with T-LGL leukemia.
Clinical Presentation: Patient 1 was a 70-year-old woman, with lymphoplasmacytic lymphoma, refractory to chlorambucil-rituximab treatment. She developed during the follow up a γHCD with T-LGL leukemia, unresponsive to melphalan, thalidomide, and steroids, requiring supportive care. Patient 2 was a 40-year-old man with chronic severe asymptomatic neutropenia, revealing both γHCD and T-LGL leukemia. He is still well without any treatment nor complications, with 7 years follow up.
Conclusion: Several types of B lymphoproliferative disease are associated with LGL leukemia. Although exceptional, this association of two rare lymphoproliferative disorders, with a different phenotype, does not seem fortuitous.