Extramedullary plasmacytoma of stomach.

A single case of gastric plasmacytoma showing unusual clinical and pathological features is described. The patient had gluten sensitive enteropathy, and showed increased circulating IgA levels prior to gastrectomy. Progression of the disease was associated with both K and L light chain proteinuria, hypoalbuminaemia, and vasopressin resistant polyuria. Pathological investigation revealed the coexistence of IgA secreting soft tissue plasmacytoma, with IgG secreting myeloma. The significance of these findings is discussed.