Cutaneous nodular amyloidosis masquerading as a foot callus

We report a unique case of a 69-year-old man who presented with a 1-year history of pink nodules and plaques limited to the anterior plantar surface of the right foot and a 30-year history of a callus on the right heel. Histologic examination findings of both areas showed deposits of amorphous, eosinophilic material and an infiltrate of plasma cells in the dermis. Congo red-stained deposits exhibited apple-green birefringence with polarized light. Results of an extensive clinical and laboratory evaluation showed no evidence of systemic amyloidosis. The diagnosis of nodular primary localized cutaneous amyloidosis (PLCA) was made. Nodular PLCA isolated to pedal or strictly plantar surfaces is an unusual presentation of PLCA. The origin and the clinical and histopathologic features of nodular PLCA are reviewed.