The Authors report a case of Castleman's disease in a 45-year-old woman. She was admitted to hospital because of a thrombophlebitis of the left lower limb. An abdominal echotomography showed evidence of a mass with a diameter of about 6 cm at the pancreatic isthmus, and a cyst (diameter 25 mm) in the right ovary. An explorative laparotomy was performed and the masses were removed. Histological examination identified them respectively as a Castleman's disease of hyaline-vascular type and an endometrioid carcinoma of the ovary.