[Richter's syndrome. A morphological study apropos of 3 cases]

The occurrence of a large cell lymphoma in the course of chronic lymphocytic leukemia is rare and its evolution is fatal at short term. This is the definition of Richter's syndrome. The authors report three cases documented by cytology, histology. The immunological study was performed for one of these by typing on a suspension of fresh bone marrow and lymph node cells. It showed the immunological identity of the chronic phase and the transformation phase (Richter's syndrome). These findings are in line with recent studies showing the immunocellular filiation of the two hemopathies despite the morphological differences, the transformation phase showing the differentiation of the B clone of the chronic phase.