[A case report of primary hemangiopericytoma of the chest wall].

A 35-year-male was found to have an abnormal shadow with an extrapleural sign located in the right lower lung field by a chest X-ray. Chest CT revealed a well demarcated tumor in the chest wall adjacent to the 4th rib. Chest MRI showed that the tumor contained punctate or linear low-intensity areas, which were considered to be small blood vessels. A diagnosis of hemangiopericytoma was established by percutaneous needle biopsy. Under the definite diagnosis, extended resection of the chest wall was performed to remove the tumor with a surgical margin of more than 5 cm, corresponding to surgery for other malignant soft-tissue neoplasmas. Hemangiopericytomas rarely arise in the chest wall, although they can be found in any region which contains pericytes. Preoperative definite diagnoses of hemangiopericytoma have rarely been reported. However, preoperative diagnosis is an important factor in deciding the operative procedure for hemangiopericytoma. It has been reported that hemangiopericytomas show local recurrences and distant metastases, although they are histologically benign. We consider that hemangiopericytomas in the chest wall should be treated with extensive resection corresponding to surgery for other malignant soft-tissue neoplasmas.