Non‐excretory Multiple Myeloma

Abstract

The clinical and laboratory features in five patients with non-excretory myeloma are described including plasma cell immunofluorescence and, in two cases, ultrastructure. Findings are compared with those in similar patients previously reported, and those in excretory disease. Clinical, haematological 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 is possible on the basis of immunofluorescence. Differing patterns of intermittent excretion occurred in three of these patients.

Nonsecretory Multiple Myeloma

“…The presence of cyto plasmic monoclonal immunoglobulins, as demon strated in 4 of our cases and in many other previously reported cases [1,10,15], indicates that plasma cells are most commonly able to synthesize immunoglobu lins, but not to excrete them (so-called 'true nonsecre tory' or 'nonexcretory myeloma'). There are two pos sible explanations for the failure in the release of im munoglobulins: first, a block in the excretory process, due either to the absence of the protein which carries immunoglobulins through the endoplasmic reticulum or to the presence of abnormal immunoglobulins which are not recognized by the carrier [14]; second, the intracellular degradation of immunoglobulins [10,15]. Furthermore, the recognition of structurally hom ogeneous proteins both in the cytoplasm and on the cellular surface has recently led to the hypothesis that plasma cells may also be able to excrete immunoglob ulins, which are then subsequently degraded [15].…”

“…8,16]. It still remains to be clarified whether in these cases plasma cells have either lost the capacity of synthesizing im munoglobulins or if they synthesize an antigenically unrecognizable product [10],…”

“…The data presented in the literature on nonse cretory myeloma are controversial. In some studies, no difference with M-protein-producing cases could be recognized [10], whereas other studies found a less advanced disease and/or less impaired immunoglob ulin values in nonsecretory patients [6,8,12,14,16]. Similarly, controversies also exist as to whether the clinical course and prognosis of this disease variant are different from those of typical myelomatosis [2,3,6,12], In order to investigate whether nonsecretory mye loma is a distinct clinical entity we analyzed a series 1 of 7 consecutive patients.…”

Non-secretory multiple myeloma with lytic bone lesions about a new observation

“…The pathogenesis of this lack of secretion has been the subject of much debate. In some cases intracellular immunoglobulins were found by immunofluorescence [9,10], indicating a defect in immunoglobulin secretion rather than production, while in other cases no intracellular immunoglobulin was found [7][8][9][10]. Putham and Miyake suggest that malignant cells in some cases synthesize or excrete a pathological immunoglobulin undetectable by conventional techniques [11].…”

Hypercalcaemia in a patient with non-secretory myeloma

“…It has been recognized that this so called non-secretory myeloma can cause hypercalcaemia.' 2 Radiographs of the skeleton have, however, always previously shown the typical lytic lesions of multiple myeloma in these circumstances.…”