[Chemotherapy-resistant CD7-positive stem cell lymphoma presenting with intra-abdominal mass]

We report a case of CD7+ stem cell lymphoma. A 47-year-old man presented with general malaise and lumbago in April 1997. The patient exhibited swollen left cervical lymph-nodes and an intra-abdominal bulky mass. He was referred to us because lymph-node biopsy specimens indicated a diagnosis of diffuse type malignant lymphoma. An abdominal CT scan disclosed large retroperitoneal, para-aortic, and mesenteric root masses. Bone marrow involvement was shown by bone marrow biopsy specimens, though no circulating blasts were detected at presentation. The patient was treated with high-dose CHOP therapy without any benefit. Though ESHAP therapy was performed as salvage chemotherapy, the abdominal masses did not shrink at all. The patient died of tumor progression in November 1997. In the terminal stage, the lymphoma cells emerged in the peripheral blood and thus became available for analysis. The cells expressed CD5, 7, 34, 38, 71, but were negative for CD1, 2, 3, 4, 8, 10, 13, 14, 16, 19, 20, 21, 25, HLA-DR, and EMA. An immunoglobulin heavy chain gene rearrangement band was detected by Southern blot analysis. However, no T cell receptor lambda or beta chain gene rearrangement bands were detected.