Multiple myeloma is characterized by either a focal or a diffuse abnormal overgrowth of plasma cells, occurring predominantly in the 40- to 70-year age group.
Features of this disease, not dermatological, are (1) pain in the bones, (2) pathological fracture, (3) neurologic manifestations, (4) gastrointestinal symptoms, (5) fever, (6) splenomegaly and hepatomegaly, (7) lymphadenopathy, (8) extramedullary lesions, (9) roentgen abnormalities, (10) kidney abnormalities, and (11) pulmonary involvement.
The characteristic cells of the relatively benign, chronic multiple myelomas are the "typical" plasma cells, according to Campbell and Good.1 They are characterized by four simultaneous structural features: 1. Heavy plaque-like chromatin aggregations in the nucleus, with sharp boundaries (in contradistinction to the chromatin lumps seen in lymphocytes); these account for the well-known cartwheel nucleus. 2. Intense basophilia of the cytoplasm. 3. The presence of a clear space in the nucleus, usually in the widest