A rare case of hyaline-type Castleman disease in the liver.

Castleman disease often develops in the neck, mediastinum and pulmonary hilum. Its onset in the peritoneal cavity is very rare. The patient, a woman in her 70s, was referred to our department for a detailed examination of an abdominal mass. On abdominal ultrasonography, computed tomography scan, magnetic resonance imaging and positron emission tomography, a mass approximately 15 mm in diameter was noted in the hepatic S6. We attempted radical treatment and conducted a laparoscope-assisted right lobectomy. On the basis of histopathological findings, the patient was diagnosed as having hyaline type Castleman disease in the liver, a very rare condition.