Monoclonal gammopathy--a diagnostic challenge. Illustrated by four cases of multiple myeloma with an unusually indolent (smoldering) course.
Four patients with IgG multiple myeloma (MM) and an unusually indolent course are presented. They had received no cytostatic therapy for 12--23 years. The M-component was initially 25--33 g/l, the bone marrow plasma cell percentage was 4--6%, but bone lesions were not demonstrated. A marked increase in size of the M-component and in the plasma cell percentage was noted in all patients, but a definitely neoplastic proliferation in only one patient. Spontaneous regression of the M-component was observed in two patients. In the light of the present cases we believe that neither a high level of the M-component nor an increase in its size should be used alone as indicators of a malignant course in MM patients. An indolent, non-progressive variant obviously occurs as one extreme in the clinical spectrum of this disorder with a course sometimes extended over 10--20 years.
D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000175:diagnosis*
D007074:Immunoglobulin G