Castleman disease with renal amyloidosis: imaging findings and clinical significance.

We report two cases of renal amyloidosis associated with mesenteric and mediastinal Castleman disease of plasma cell type. Computed tomographic (CT) scan revealed a mesenteric mass with multiple nodal enlargement in one patient and a right paratracheal mass with irregular central calcifications in the second patient. Renal ultrasonography (US) showed increased echogenicity of the renal parenchyma with prominent medullas. Doppler waveform obtained in the kidney associated with mesenteric disease showed complete absence of diastolic flow signal, although it was normal in the patient with mediastinal disease. Recognition of Castleman disease as the cause of renal amyloidosis and the understanding of CT and US findings of this entity are important for the management, as well as its diagnosis.