[Nodular cutaneous amyloidosis. Clinical, histopathological and ultrastructural findings]

A case of nodular amyloidosis cutis of the face with minimal deposits of amyloid in the rectum is reported with respect to clinical, histopathological, and ultrastructural findings. A discussion of the problem of systematization in nodular amyloidoses is included. By electron microscopy, the principal similarity of the ultrastructure of amyloid is stressed again. Amyloid in this case of nodular amyloidosis cutis is thought to be synthesized by plasma cells which are found especially in the growing peripheral parts of the tumors. Fibroblasts with extremely dilated endoplasmic reticulum are almost totally surrounded by the fibrillar masses of amyloid within the tumor. Unusual spindle-formed cisternae of Golgi bodies containing oriented coarse fibrils are found in the fibroblasts. They are thought to represent a disturbance of the secretion of tropocollagen to the interstitium due to the surrounding amyloid masses.