title: Immunoglobulin crystals in reactive plasma cells in a dog.
abstract: Intracellular crystalline deposits of immunoglobulin are occasionally seen in human B-cell lymphoproliferative disorders such as multiple myeloma, chronic lymphocytic leukemia, and various forms of lymphoma. Even more uncommon is the occurrence of immunoglobulin crystals in benign plasma cells or reactive lymphocytes. Here we describe the histologic, immunohistochemical, and ultrastructural features of intracellular immunoglobulin crystals in nonneoplastic plasma cells in a chronic inflammatory lesion in a dog. Microscopically, the intracellular, nonbirefringent eosinophilic crystals were square to rectangular, 2-20 microm long, and caused nuclear displacement to the periphery. The crystal-containing cells, as well as some of the crystals themselves, were positive for lambda light chain. Ultrastructural findings were consistent with a lattice network of protein-molecule alignment. The cause and significance of the crystals is unknown.
authors.affiliation: Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA.
authors.forename: B
authors.initials: B
authors.lastname: Zimmerman
authors.forename: M I
authors.initials: MI
authors.lastname: Yamaguchi
authors.forename: L J
authors.initials: LJ
authors.lastname: Rush
mesh_terms: D000818:Animals; D002908:Chronic Disease; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D004427:Ear Diseases / Q000473:pathology / Q000662:veterinary*; D005260:Female; D007136:Immunoglobulins / Q000378:metabolism*; D007249:Inflammation / Q000473:pathology / Q000662:veterinary; D010950:Plasma Cells / Q000378:metabolism*
chemical_list: D007136:Immunoglobulins