title: J-chain-producing immunoblastic lymphoma in a case of Richter's syndrome. Immunohistochemical evidence for a gradual malignant transformation of a single B-cell clone and flow cytophotometric data.
abstract: A 66-year old male with Richter's syndrome died 52 month after diagnosis of chronic lymphocytic leukaemia (CLL). The clinical course was characterized by a marked IgM hypoglobulinaemia which paralleled a chronically relapsing Herpes simplex infection. Autopsy showed a large retroperitoneal and intraabdominal tumour mass and well defined supradiaphragmatic lymphomas. Histological examination revealed a composite tumour consisting of CLL B-cell type (B-CLL) and immunoblastic malignant lymphoma of B-cell type (B-IbL). The lymphocytes bear mu-chains on their surface and to a lesser extend within their cytoplasm, the obviously defective immunoblasts produce J chains exclusively. Flow cytophotometric data seem to indicate an identical diploid stem line of the two tumours. The majority of the cells are in G0/1 phase. The CLL rarely produces mitoses, however, the IbL has a mitotic rate of 7% and a considerable proportion (33%) of cells in the phase of DNA-synthesis. This is the fourth malignant lymphoma and the second immunoblastic lymphoma to be reported that produces J chain in the absence of immunoglobulin.
mesh_terms: D000008:Abdominal Neoplasms / Q000150:complications* / Q000473:pathology; D002453:Cell Cycle; D005434:Flow Cytometry; D006801:Humans; D007144:Immunoglobulin J-Chains / Q000096:biosynthesis*; D007945:Leukemia, Lymphoid / Q000150:complications* / Q000473:pathology; D008198:Lymph Nodes / Q000473:pathology; D008228:Lymphoma, Non-Hodgkin / Q000150:complications / Q000276:immunology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary; D013577:Syndrome
chemical_list: D007144:Immunoglobulin J-Chains