Solitary myeloma with massive extracellular crystalline structures: a case report

We describe a case of solitary myeloma showing cystic change filled with massive crystalline structures in a 54-year-old woman. A bone X-ray showed a solitary cystic osteolytic lesion in the right iliac bone. Serum and urine protein electrophoresis showed no demonstrable M-protein, and bone-marrow aspirates did not show any myeloma cells. Histologic examination of the tumor revealed aggregation of plasma cells with massive extracellular infiltration of the rhomboid-shaped crystalline structures. In immunoperoxidase staining, both these crystalline structures and the cytoplasms of the myeloma cells demonstrated a positive reaction for lambda light chain. By electron microscope, the large extracellular crystalline structures were observed, and we found unique rhomboid or rectangular-shaped crystalline structures in the cytoplasms of the myeloma cells.

Reticulin antibodies: relationship with endocardium-vessel-interstitium antibodies and heterophilic antibodies

Indirect immunofluorescence was used to compare reticulin antibodies, endocardium-vessel-interstitium (EVI) antibodies and heterophilic antibodies in serum samples from patients with degenerative and inflammatory diseases, Chagas' disease, or paracoccidioidomycosis and from healthy blood donors. The antigen substrates used were rat, mouse and human liver for reticulin antibodies, mouse and human heart and skeletal muscle for EVI factor, and rat heart and rat, mouse and human kidney and stomach for heterophilic antibodies. The three antibodies produced extremely similar fluorescent patterns and were present simultaneously in a large proportion of reticulin-positive serum samples. The three antibodies were significantly absorbed by heterophilic antigens such as sheep and rat red blood cells and guinea pig kidney, by Trypanosoma cruzi (an antigen associated with EVI factor) and by Paracoccidioides brasiliensis. However, they did not react with several human tissues. These results suggest that reticulin and EVI antibodies can be considered to be heterophilic antibodies