Unicentric Castleman's disease complicated by systemic AA amyloidosis: a curable disease.

BACKGROUND: Castleman's disease (angiofollicular lymph node hyperplasia) is a group of rare lymphoproliferative disorders sharing characteristic clinical and histological features, and usually accompanied by a marked systemic inflammatory response. All types may be complicated by acquired systemic amyloidosis, usually of AA type, but occasionally of AL type associated with monoclonal gammopathy.
DESIGN: Descriptive study of five patients with unicentric Castleman's disease complicated by systemic AA amyloidosis.
METHODS: A diagnosis of amyloidosis was confirmed by microscopy and immunohistochemical staining. Serum concentrations of C-reactive protein (CRP) and serum amyloid A protein (SAA) were measured by immunoassays. Radiolabelled serum amyloid P component scintigraphy was used to monitor the progress of amyloid deposition.
RESULTS: In four patients the primary diagnosis was made only after years of investigation of systemic symptoms. The tumours were resected in all cases, leading to remission of the systemic inflammatory state. Long-term follow-up in four patients, including scintigraphy, showed regression of amyloid deposits. DISCUSSION: This rare but usually fatal condition can be cured surgically even in advanced cases. Awareness of the diagnosis and its correct management are important in investigation of patients with unexplained systemic symptoms, especially associated with systemic amyloidosis.