Secondary localized amyloidosis in trichoepithelioma. A light microscopic and ultrastructural study

Two trichoepitheliomas with secondary localized amyloidosis were documented in a 74-year-old man. The ultrastructural findings support an origin of amyloid from tumor cells. It is suggested that the occurrence of amyloid is a reflection of the ability of tumor cells to produce an excessive number of tonofilaments from which amyloid is believed to be derived. The intimate spatial association between amyloid and fibroblasts may suggest the existence of some yet undefined functional relationship.