The management of disordered immunoglobulin metabolism is generally difficult. Features of diagnosis and evaluation have slowly accumulated through years of observation. Crystalline inclusions may be seen in patients with a protracted course of myeloma, and their presence indicates that the patients may not require chemotherapy.
A 59-year-old laundry worker had a prolonged course of myeloma from August 1976 to February 1984. Crystals were present in the bone marrow biopsy specimen. He was found to have an elevated level of monoclonal IgG of K type in his serum. Chemotherapy for myeloma was instituted in the last few months of his life, without improvement of status. His terminal serum urea nitrogen level was 58 mg/dL; creatinine, 3.8 mg/dL.
Aspirate smears obtained in 1976, 1977, 1978, and 1982 showed similar morphological features. There were approximately 10% to 15% large cells with oval nuclei and prominent blue to slate-gray cytoplasm containing variably sized, poorly