Histopathological regression of systemic AA amyloidosis after surgical treatment of a localized Castleman's disease.

Previously, we reported a case of localized plasma cell type Castleman's disease with severe hepatomegaly and reactive systemic AA amyloidosis. The amyloid deposits were demonstrated in both the hepatic tissue and in the gastric mucosa. Surgical resection of an isolated extra-hepatic tumor was performed. The laboratory findings, including SAA and IL-6, remained within normal limits and the patient's hepatomegaly subsequently showed regression. Nine years after the operation, no amyloid deposition was seen in the gastric mucosa and the patient's liver was of normal size. Our findings with long-term follow up in this case indicated that the cessation of SAA production was the probable cause of histopathological regression of AA amyloid deposits in this patient.