Multiple myeloma: a clinicopathologic study of 62 consecutively autopsied cases.

The clinical, laboratory and pathologic findings were studied in 62 consecutively autopsied patients with multiple myeloma between 1954 and 1975. All patients were 40 years of age or older. Bone pain was the initial symptom in 2/3 of patients. Anemia (81%), thrombocytopenia (29%), azotemia (41%), hypercalcemia (46%) and hyperuricemia (52%), were common laboratory findings at diagnosis. Ninety-seven percent had a monoclonal protein in serum or urine. Extensive plasma cell replacement of marrow was invariably seen at autopsy although in 15% of patients no abnormality was found on skeletal survey. Extraskeletal spread (67%) was due to direct extension to paraosseous tissue resulting from cortical destruction and to distant organ involvement mainly of splenic red pulp and hepatic sinusoids. The patients were susceptible to bacterial infection, mainly gram-negative, of the lung (56%), urinary tract (35%), and blood (24%). Fungal infection was less frequent and usually consisted of superficial candidal overgrowth of gastrointestinal tract ulcerations (18%). Amyloidosis (10%) was perivascular and associated with light chain proteinuria. Renal failure as a cause of death (21%) was secondary only to infection (52%). Severity of histologic findings in the kidney at autopsy had little correlation to initial BUN concentration. The median survival was 11.5 months with alkylating agent therapy (responders, 29 months; non-responders, 6 months), and 6 months with urethan. Initial azotemia (greater than 80 mg/dl) and hypercalcemia (greater than 12 mg/dl) were important prognostic indicators (median survival, less than 1 month and 3 months, respectively). A good response to alkylating agent therapy, initial BUN less than 40 mg/dl and serum calcium less than 12 mg/dl were favorable to prognostic indicators.