Primary Localized Cutaneous Amyloidosis (Tumefactive Form)

—Histochemical and Electronmicroscopical Difference from Colloid Degeneration of the Skin (Plaque Type)—

Abstract

A 63-year-old male with solitary nodule on the left cheek is presented. The nodule is composed of amorphous material which completely filled up the whole dermis. Clinical and histochemical characteristics indicated colloid degeneration of the skin (plaque type). However, electronmicroscopically we found co-existence of colloid-like filaments and amyloid filaments in the material and finally we considered that the disease is one of the atypical type of primary localized cutaneous amyloidosis (tumefactive form).