A Case of Localized Cutaneous Nodular Amyloidosis with Peculiar Amyloid Deposition Which Contributed to the Initial Diagnosis of Sjögren Syndrome

Abstract

A 68-year-old female presented with a number of brownish nodules and yellowish plaques with bullous clinical appearance on the abdomen and bilateral lower extremities. Skin biopsy revealed well-circumscribed amorphous materials with plasma cell infiltration surrounding the sweat glands in the dermis, which was revealed to be amyloid deposition by amyloid staining. Amorphous materials were positively stained with anti-AL-κ monoclonal antibody. Detailed examination revealed positive antinuclear, anti-SS-A antibody, as well as impaired secretion of saliva and lacrimal fluids, and the patient was diagnosed with Sjögren syndrome. Peculiar amyloid deposition restricted around the sweat glands is rare, and only four cases have been reported including the present case. The possible mechanisms of peculiar amyloid deposition are discussed.