Crystalglobulin-induced vasculopathy accompanying ischemic intestinal lesions of a patient with myeloma.

A 37 year old man with multiple myeloma (IgG lambda) developed perforation of the small intestine and had gangrene in his feet. In the resected small intestine and below-knee amputated feet, intravascular deposition of crystals, immunohistochemically positive for IgG and a lambda light chain, were found. Although paraproteins produced in the course of plasma cell dyscrasia may crystallize and cause systemic occlusive vasculopathy, this is the first case with intestinal involvement. Because cryoglobulinemia was absent in this patient, crystals may be derived from the myeloma protein which sometimes crystallizes in the blood without the influence of low temperature.