Multicentric Castleman's disease with multiple hepatic mass lesions mimicking malignant liver tumors.

Multicentric Castleman's disease (MCD) is a rare, non-malignant lymphoproliferative disorder. We report a case of MCD with multiple liver masses. A 26-year-old woman presented with asymptomatic anemia and hypoalbuminemia. Laboratory tests detected high CRP levels and findings indicative of polyclonal gammopathy. Abdominal CT revealed multiple hepatic large masses (≤10 cm) and partial calcification in the right lobe. Multiple enlarged lymph nodes were also identified in the cardiophrenic angle and porta hepatis. We suspected hepatic malignancy, but pathological examinations of the liver and lymph nodes demonstrated polyclonal plasma cell infiltration and fibrosis. IL-6 staining was positive for plasma cell infiltration of lymph nodes. A few plasma cells were positive for IgG4, and tests for HIV and HHV-8 were negative. Serum IL-6 and plasma VEGF levels were both elevated (45 and 536 pg/ml, respectively). The patient was diagnosed with plasma cell type MCD. We started treatment with PSL 1 mg/kg/day, which led to improvement of anemia, hypoalbuminemia, and high CRP levels. Marginal regression of liver masses was also observed. At the last follow-up, the patient had been progression-free for 18 months. To our knowledge, this is the first report of a plasma cell type MCD with liver masses.