Malignant lymphoma presenting in the orbit: a clinicopathologic study of a rare immunoglobulin-producing variant.

Malignant lymphoma with orbital presentation and associated serum paraproteinemia has seldom been reported in the literature. We report two such cases of lymphoplasmacytic type, one of which was also associated with amyloidosis. Both cases were studied with immunohistologic and one with electron microscopic techniques with results that confirmed that the neoplastic cells were producing the abnormal serum immunoglobulin.