A case of long-term unchanged calcifying fibrous tumor.

A calcifying fibrous tumor (CFT) is a rare benign tumor that may occur in any part of the body. We report the case of an asymptomatic 21-year-old woman with thoracic tumors. Chest computed tomography showed multiple masses in the left costophrenic angle. As we were unable to diagnose the tumor with a CT-guided needle biopsy, we performed a thoracoscopic biopsy. We found smooth multilobulated masses on the pleura and multiple small nodules around the main tumors. Partial resection of the tumor was performed by VATS. Histological examination revealed that the tumor had hypocellular fibrosclerotic tissue and distributed psammomatous calcifications with inflammatory infiltrates. Immunohistochemistry demonstrated that the spindle cells were partially positive for CD34 and CD99, but negative for anaplastic lymphoma kinase-1, smooth muscle actin, BCL-2, STAT6, and S-100 protein. The tumor was diagnosed as CFT. The patient's postoperative recovery was uneventful, and no progression of the lesions was observed during follow-up.