P2.04-039 Long-Term Risk of Recurrence in Benign Pleural Solitary Fibrous Tumors: A Single Institution Review: Topic: Esophageal Cancer and Other Malignancies

Abstract

Solitary fibrous tumor (SFT) is a rare tumor of submesothelial origin that can occur in the abdomen, extremities, trunk, head, neck and pleura. Pleural SFTs are defined as benign or malignant based on the number of mitoses and the presence of pleomorphism, hemorrhage, or necrosis. There is limited data in the literature regarding the recurrence risk of benign pleural SFT and the need for long-term follow up in these patients. A single institution retrospective chart review was performed on all surgically resected primary pleural SFTs between 1992 and 2015. Preoperative clinical information, pathologic tumor characteristics, and long-term recurrence and survival data were collected. There were 29 primary pleural SFTs resected between 1992 and 2015. Patients had a mean age of 60 years and there were 16 men (55%) and 13 women (45%). Fourteen (48%) presented with symptoms, including two patients with paraneoplastic syndromes, and the other 15 tumors (52%) were found incidentally on imaging. There were six giant SFTs defined as size greater than 15 cm, with two of six giant SFTs undergoing preoperative embolization to aid surgical resection. Otherwise, there were no neoadjuvant or adjuvant treatments in any patient. There was no perioperative 30-day mortality (0%). Mean follow up time was 77 months, during which 4 (14%) patients recurred and 21 of 29 patients (72%) were alive at last follow up. Three of the 8 deaths occurred in patients with recurrent disease. Among the 19 benign pleural SFTs, 2 (11%) recurred at 5 and 9 years postoperatively and 2 of the 6 malignant SFTs (33%) recurred at 4 and 15 years postoperatively. Margin status was known in 25 cases, of which 21 (84%) were negative and 4 (16%) were positive. There were no recurrences in patients with known negative margins. This study represents one of the largest contemporary single institution reviews of outcomes of pleural SFT. While benign pleural SFTs were less likely to recur than malignant pleural SFTs, benign pleural SFTs with positive or unknown margin status remain at risk for recurrence up to a decade following resection and require ongoing long-term follow up and surveillance imaging.