Lymphoplasmacytoid lymphoma elaborating lambda chain paraprotein with amyloid deposition in Sjögren's syndrome

A woman presented with painful enlargement of her parotid and submandibular glands. She was shown to have the previously unreported combination of idiopathic thrombocytopenic purpura, Sjögren's syndrome, Hashimoto's disease, and myasthenia gravis. Parotid gland biopsy and bone marrow examination showed the presence of a rare lymphoplasmacytoid lymphoma. There was amyloid deposition in the parotid glands, gums and on muscle biopsy. Immunohistochemical staining of the parotid lymphoma and amyloid was monotypic for lambda light chains, and there was also a lambda chain paraprotein. It is felt that the lymphoplasmacytic lymphoma was responsible for the light chain amyloidosis.