[Primary hepatosplenic T-cell (gamma delta) lymphoma: morphology and immunohistochemistry in 3 cases].

We analyzed one autopsy case and two biopsy cases of primary (hepato-)splenic lymphoma, diagnosed in numerous trephine bone marrow, spleen and liver biopsies. It is a distinctive "new" type of a rare T-cell lymphoma characterized usually by rearrangement of gamma delta chains of T-cell receptor. Morphologically, the lymphoma is composed of a cytologically monotonous proliferation of small to medium sized lymphocytes, with diagnostically characteristic intrasinusoidal spread in the bone marrow, spleen and liver. The involvement of the lymph nodes is always absent. Immunohistochemically, the tumor cells expressed constant CD3 positivity and negativity for B- and myelomonocytic antigens, together with an inconstant coexpression of CD43 and CD45RO. In contrast to other and more common primary B-cell splenic lymphomas, its biological behaviour is more aggressive.