Non‐excretory Multiple Myeloma

Abstract
The clinical and laboratory features in 5 patients with non-excretory myeloma were described including plasma cell immunofluorescence and, in 2 cases, ultrastructure. Findings were compared with those in similar patients previously reported and those in excretory disease. Clinical, hematological and biochemical features were similar to those found in excretory myeloma, showing differences only in relation to the absence of serum or urinary monoclonal immunoglobin. Cellular cytological and ultrastructural features allowed no differentiation from excretory cells. Within this non-excretory group distinction between secretory and non-secretory myeloma cells was possible on the basis of immunofluorescence. Differing patterns of intermittent excretion occurred in 3 of these patients.