Diagnosis: Bullous amyloidosis.
MICROSCOPIC FINDINGS
Histologic examination from the periphery of a lesion on the left upper thigh revealed amorphous, eosinophilic deposits in the papillary dermis, along a hair follicle, and surrounding multiple blood vessels throughout the dermis. These deposits displayed apple-green birefringence on Congo red staining with polarized light. One portion of the biopsy specimen showed separation of the superficial dermis and epidermis from the underlying dermis.
DISCUSSION
Amyloidosis is a family of diseases characterized by extracellular deposition of amyloid, which causes architectural dysfunction in affected tissues. Amyloid protein complexes have a distinct ultrastructure, comprised of 7.5- to 10-nm-thick, linear, nonbranching fibrils of varying lengths.1 Amyloid is visible microscopically as an amorphous, eosinophilic substance. After staining with Congo red, amyloid displays a classic apple-green birefringence using polarization microscopy.
Clinically, amyloidosis can be either localized or systemic.2 Systemic amyloidosis is further divided into primary and myeloma-associated or secondary forms; AL amyloidosis is primary systemic amyloidosis and . . . [Full Text of this Article]