"Myeloma lung"--a previously unreported complication of multiple myeloma.

A 52-year-old man with known lambda light-chain multiple myeloma developed chronic renal failure, which was proven by renal biopsy to be the result of "myeloma kidney." Terminally, disseminated pulmonary infiltrates developed. Postmortem examination showed the infiltrates to consist of neoplastic plasma cells with crystalline casts, strikingly similar to those found in the kidneys. The term "myeloma lung" is proposed to describe this unusual and heretofore unreported complication of multiple myeloma.