P3.04-039 Solitary Fibrous Tumor of the Pleura Associated with Gynecomastia: A Case Report: Topic: Miscellaneous II

Abstract

Fibrous tumor originated from pleura is a rarely seen lung tumor. It can be malignant or benign, and may cause paraneoplastic syndromes. In this study, we retrospectively evaluated a case in which a lung mass was detected during examination of the gynecomastia and operated in our hospital with the diagnosis of solitary fibrous tumor of the pleura. 53-year-old male patient was admitted to our clinic with the complaint of bilateral painful breast enlargement. Symmetrical gynecomastia with benign findings was detected in Category 2 level according to Breast Imaging-Reporting and Data System (BI-RADS) classification in the bilateral breast ultrasonography investigations. Thorax computed tomography imagination showed extrapleurally located mass lesion with solid character and 75x25mm in size. Mesothelial cells were observed in the material received by the computed tomography-guided needle biopsy. Thereupon, a decision was made to take the patient to the operation. Frozen section procedure was performed on the specimen received by video-assisted thoracic surgery (VATS) biopsy. Diagnosis could not be achieved therefore it was decided to perform resection by mini-thoracotomy due to the size and rigid structure of the mass. During the process, it was observed that fibrous mass was holding on to the right middle lobe with a pedicle and it was found to be free in the other regions. The entire mass was removed with the resection including the surrounding healthy parenchymal tissue and the operation was terminated. The patient was discharged on the postoperative day 3. In the pathological examination, a solitary fibrous tumor associated with visceral pleura in the dimensions of 85×55×27 mm was reported with the features of low mitotic activity, and focal hypercellularity, and showing strong positive staining for CD34, CD99 and Bcl-2. In the additional investigations in gynecomastia clinics, it was observed that tumor cells were stained at 67-70% with progesterone and 35-40% with estrogen. Staining with β-Hcg was not observed. Solitary fibrous tumors of pleura is rare. These tumors originate from mesenchymal cells, not from mesothelial cells. These solitary fibrous tumors may be malignant or benign. These tumors may be asymptomatic, may cause symptoms of pressure or may lead to paraneoplastic syndromes. Recurrence can happen. Appropriate surgical intervention should be selected.