Multicentric Castleman's disease found by a retroperitoneal tumor: A case report

A 56-year-old man was admitted to our hospital with a 14 month history of intermittent left-sided lumbago and night sweating. Two months prior to admission, the patient was incidentally found to have a retroperitoneal tumor at a local hospital. Computed tomography (CT) and magnetic resonance imaging (MRI) confirmed a calcified solid retroperitoneal mass separate from the kidney, without invasion of any adjacent organs, together with multicentric lymphadenopathy in the retroperitoneum and the mediastinum. There were also left sided pleural effusion and splenomegaly. Admission laboratory tests, including complete blood count and serum chemistry panel, were unremarkable except for an elevated erythrocyte sedimentation rate. Percutaneous biopsy of the retroperitoneal tumor showed a hyalinized germinal center and marked proliferation of small vessels. Together with these findings, a clinical diagnosis of multicentric Castleman's disease (MCI) was made. Surgical excision of the retroperitoncal mass revealed a lobulated yellow tumor with a diffuse and rich vascularity. Histological examination of the excised mass confirmed its similarities with those of the hyaline vascular variant of Castleman's disease. Although Castleman's disease generally has a good prognosis, MCD is associated with significant morbidity and mortality. In our case, the size of the residual lymph nodes has been decreasing since surgery and the patient has remained free from disease for 10 months.