Malignant Lymphoma with Intracytoplasmic IgM Crystalline Inclusions

Abstract

INTRACYTOPLASMIC crystalline inclusions occurring in circulating lymphocytes in chronic lymphocytic leukemia and in the neoplastic cells of plasma-cell tumors have been the subject of several case reports ^{1 2 3 4}; in all, electron microscopy and immunofluorescent studies have demonstrated the inclusions to be located within the cisternae of the rough endoplasmic reticulum and to represent synthesized but unreleased immunoglobulin.In the case of malignant lymphoma reported below, intracellular crystalline IgM inclusions were demonstrated in cells identified by conventional means as lymphocytes and "histiocytes." This finding merits discussion in the light of current knowledge about immunoglobulin biosynthesis by the cells of malignant "lymphoreticular" . . .