title: Primary cutaneous nodular amyloidosis associated with psoriasis.
abstract: Primary cutaneous nodular amyloidosis (PCNA) presents as solitary or multiple firm, waxy nodules with a predilection for acral areas. Histologically, PCNA can be identical to myeloma-associated systemic amyloidosis with monoclonal immunoglobulin light chain deposits. We describe a patient in whom PCNA developed in a scar in an area affected by chronic plaque psoriasis. PCNA has previously been associated with other autoimmune diseases, but to our knowledge, this is the first association with psoriasis. Interestingly, T helper (Th)17 cells, which are crucial in psoriasis pathogenesis, have recently been implicated in promotion of myeloma and plasma cell dyscrasias. The association of psoriasis and plasma-cell light chain production in the skin, as in this case, suggests a possible role for Th17 cells in PCNA formation. The dermatopathological literature of this rare but important disease is discussed.
authors.affiliation: Department of Dermatology, University Hospitals Southampton NHS Foundation Trust, Southampton, UK.
authors.forename: C Y
authors.initials: CY
authors.lastname: Ung
authors.forename: N J
authors.initials: NJ
authors.lastname: Carr
authors.forename: M R
authors.initials: MR
authors.lastname: Ardern-Jones
mesh_terms: D000328:Adult; D028226:Amyloidosis, Familial / Q000473:pathology*; D005260:Female; D006801:Humans; D011565:Psoriasis / Q000150:complications*; D012873:Skin Diseases, Genetic / Q000473:pathology*