Hepato-splenic gammadelta T-cell lymphoma: a rare entity mimicking the hemophagocytic syndrome.

Hepatosplenic gammadelta T-cell lymphoma is a rare histologic type of the peripheral T-cell lymphomas, clinically characterized by predominant involvement of liver and spleen, no or little adenopathy, and an often aggressive course; it affects mainly adolescents and young adults, with a male predominance. Postthymic T-cell malignancies are heterogeneous in their clinical and laboratory features. Among the gammadelta postthymic T-cell lymphomas, two distinct entities (cutaneous and hepatosplenic, respectively) are reported in the literature. The former shows predominant multiple involvement of the skin and subcutaneous tissue; it occurs mostly in older patients and the phenotype is CD3-, CD4-, CD8-. Because of the small number of reports, the course of the disease was unknown. The latter shows a clinical picture characterized by hepatosplenomegaly, no or little adenopathy, and sometimes systemic symptoms (fever, cytopenias likely due to hypersplenism); it presents a peculiar sinusoidal involvement of liver and spleen. The bone marrow histologic feature often reveals a little infiltration, especially sinusoidal and easily underestimated phenotype: CD2+, CD3+, CD7+, CD5-, CD4-, CD8-, CD44+. Few cases of this lymphoma associated by hemophagocytic syndrome are described (Sun, 1990; Kadin, 1981; Jaffe, 1983). We report a case of a young man with a rapid and fatal course in which the more important clinical feature was hemophagocytosis. The diagnosis of lymphoma was very difficult because of paucity of histologic involvement, and only the rearrangement of TCR gamma chain gene by polymerase chain reaction on paraffin sections confirmed a clonal T-cell proliferation.