Bullous amyloidosis is a rare cutaneous manifestation of systemic AL amyloidosis that may be associated with multiple myeloma or occult plasma cell dyscrasia

© 2010 The Authors. doi: 10.2340/00015555-0871 Journal Compilation © 2010 Acta Dermato-Venereologica. ISSN 0001-5555 Bullous amyloidosis is a rare cutaneous manifestation of systemic AL amyloidosis that may be associated with multiple myeloma or occult plasma cell dyscrasia (1–3); only approximately 30 cases have been reported until now (4, 5), although its incidence may be higher than is generally believed (3). Interestingly, the patient described here was found to have plasma cell dyscrasia only after the occurrence of bullous amyloidosis. The histopathological picture mimicked that of bullous pemphigoid because of equivocal positivity for specific amyloid staining, but electron microscopy (EM) of the deparaffinized, formalin-fixed tissue demonstrated aggregation of amyloid fibrils, which was useful for diagnosing cutaneous amyloidosis in this case.