BCC-associated amyloidosis with a peculiar pattern of deposition.

An 83-year-old Japanese woman with lepromatous leprosy had been treated in a leprosarium. More than 10 years ago, she developed a dome-like brown tumor on the dorsum of the nose which showed the histology of basal cell carcinoma. The lesion was a well bordered, rounded tumor with tumor cell nests on its periphery extending toward the center as cords of tumor nest and with amyloid depositions between the cords. The tumor nests and amyloid lessened toward the center of the tumor, being replaced by collagen fibers. Amyloidosis showing this peculiar pattern of transition was reported with a review of published cases.