Intracellular immunoglobulin G ‘Pseudocrystals’ in a patient with chronic B-cell leukemia

Abstract

A patient with chronic B-cell leukemia in whom the malignant lymphocytes showed intracellular inclusions of immunoglobulin (Ig) G kappa molecules is described. Electron microscopy revealed filamentous material in the nuclear envelopes and in the cisternae of the rough endoplasmic reticulum. These in vivo surface Ig-negative, nonexcreting cells could be stimulated in vitro to excrete immunoglobulin-free light chain molecules into the supernatant, which were not found in the cytoplasm after stimulation.

Intracytoplasmic filamentous inclusions andIGHVrearrangements in a patient with chronic lymphocytic leukemia

“…These inclusions can present multiple morphologies including vacuoles, crystals, and pseudocrystals, and they are mainly localized within the rough endoplasmic reticulum (RER) compartment. Besides, most of the reported cases indicate that these inclusions represent immunoglobulin (Ig) deposits and usually the surface Ig, when it is demonstrable, is identical to the one found in the inclusion bodies [3][4][5][6]. However, the mechanism related to the inclusions formation remains to be determined.…”