title: A case of aggressive multiple myeloma with cleaved, multilobated, and monocytoid nuclei, and no serum monoclonal gammopathy.
abstract: Multiple myeloma is a B-cell malignancy characterized by proliferation of neoplastic plasma cells. A few cases have been reported identifying variant forms of neoplastic plasma cells with atypical nuclei that secrete myeloma protein. We report a highly unusual case of plasma cell myeloma that presented with cleaved, multilobated, and monocytoid nuclei, without detectable myeloma protein in the serum or urine. The bone marrow contained sheets of plasma cells exhibiting pleomorphic nuclei with cleaved, multilobated, and monocytoid features that were negative for myeloperoxidase and dual esterase. Flow cytometric analysis revealed CD38high/CD45low cells expressing cytoplasmic kappa light chain, without evidence of myeloid or lymphoid differentiation. Following chemotherapy, the patient developed secondary plasma cell leukemia. A high plasma cell labeling index was obtained from bone marrow and peripheral blood, indicating a poor prognosis. In addition to quantitative immunoglobulins, serum protein electrophoresis, and immunofixation electrophoresis of serum and urine, we recommend cytochemical and flow cytometric studies for evaluation of suspected plasma cell myeloma with atypical cellular features.
authors.affiliation: Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, USA.
authors.forename: Y A
authors.initials: YA
authors.lastname: Yeh
authors.forename: A A
authors.initials: AA
authors.lastname: Pappas
authors.forename: J T
authors.initials: JT
authors.lastname: Flick
authors.forename: A W
authors.initials: AW
authors.lastname: Butch
mesh_terms: D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001854:Bone Marrow Cells / Q000276:immunology / Q000473:pathology; D002453:Cell Cycle; D002945:Cisplatin / Q000008:administration & dosage; D003520:Cyclophosphamide / Q000008:administration & dosage; D003907:Dexamethasone / Q000008:administration & dosage; D005047:Etoposide / Q000008:administration & dosage; D005434:Flow Cytometry; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000032:analysis; D007146:Immunoglobulin lambda-Chains / Q000032:analysis; D007952:Leukemia, Plasma Cell / Q000175:diagnosis; D008297:Male; D009101:Multiple Myeloma / Q000097:blood / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology*; D016609:Neoplasms, Second Primary / Q000175:diagnosis; D011379:Prognosis; D013792:Thalidomide / Q000008:administration & dosage
chemical_list: D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains; D013792:Thalidomide; D005047:Etoposide; D003907:Dexamethasone; D003520:Cyclophosphamide; D002945:Cisplatin