T-cell lymphomas of large cell type. A variety of malignant lymphomas: "histiocytic" and mixed lymphocytic-"histiocytic".

Clinical and morphologic features of seven T-cell lymphomas of the large cell type are described. The tumors were grouped into those with irregular (3 cases) and those with round and regular nuclei (4 cases). In both groups, variation in cell size, numerous histiocytes and vessels, and many mitoses were distinguishing features. In only 1 case in the round and regular nucleus group was there relatively little variation in cell size and a paucity of histiocytes. Abundant polyribosomes, long strands of rough endoplasmic reticulum, and lysosomal granules were prominent electron microscopic features in both groups of tumors. The clinical presentations and courses varied considerably, especially in patients with tumors of the round nucleus type. One patient presented initially with chronic lymphocytic leukemia, 1 with Lennert's lymphoma, another with bone marrow infiltration, and a fourth with subcutaneous tumors. Two patients with the round nucleus type are still alive one and a half and two years after the original diagnosis. Two patients died two years after the onset of symptoms. Each of the 3 patients with tumors of the irregular nucleus type had a rapid clinical course and died within ten months.