A patient had primary amyloidosis which showed typical cutaneous manifestations. Histochemical stains normally used in the diagnosis of amyloidosis were inconclusive. Therefore, diagnostic electron microscopic studies were carried out to assist in definitive diagnosis. The electron microscopic findings showed characteristic amyloid fibrils deposited free in the dermis, associated with collagen bundles, and around small blood vessels.
Goodman TF, Abele DC, West CS. Electron Microscopy in the Diagnosis of Amyloidosis. Arch Dermatol. 1972;106(3):393-397. doi:10.1001/archderm.1972.01620120077024