Retroperitoneal unicentric Castleman's disease with multiple lymph node involvement.

A 78-year-old woman with B-symptoms was referred for a left adrenal incidentaloma of 5 cm. Imaging revealed features compatible with adrenal cancer. The authors excluded excess production of catecholamines or adrenal steroids. The tumour was removed by en bloc radical left retroperitonectomy with adrenalectomy, nephrectomy, interaortocaval lymphadenectomy and splenectomy. Histology demonstrated periadrenal hyaline vascular Castleman's disease with local infiltration and 14 positive lymph nodes. The lymphoid infiltrate spilled into the adjacent renal cortex. HHV8 was negative. The Ki67 proliferative index was 30-40% in germinal centres. There was no syn- or metachronous disease on extended imaging including fluorodeoxyglucose positron emission tomography-CT and narrow follow-up at 3 years. This is a rare case of unicentric hyaline vascular Castleman's disease with documented locoregional lymph node involvement. The case exemplifies the transition from unifocal unicentric disease into disseminated disease with involvement of multiple lymph node stations (multicentric disease). The authors demonstrate surgical cure by oncological resection.