Primary cutaneous nodular amyloidosis in a patient with Sjögren's syndrome.

A 71-year-old woman with a history of Sjögren's syndrome presented for evaluation of a waxy nodule present on the scalp for 6 months. Histopathologic examination revealed deposition of homogenous eosinophilic material throughout the reticular dermis consistent with amyloidosis. Primary cutaneous nodular amyloidosis is a rare phenomenon characterized by the deposition of immunoglobin light chains by a clonal plasma cell population. Patients need to be monitored for progression to systemic amyloidosis or plasma cell dyscrasias.