A Rare Presentation of Primary Synovial Sarcoma of the Lung

SESSION TITLE: Lung Cancer Student/Resident Case Report Posters SESSION TYPE: Student/Resident Case Report Poster PRESENTED ON: Tuesday, October 27, 2015 at 01:30 PM - 02:30 PM INTRODUCTION: Primary synovial sarcoma of the lung is extremely rare. Extrapulmonary synovial sarcoma should be excluded to establish the diagnosis. Tumors are often located centrally and present with cough or chest pain. We describe a patient diagnosed with synovial sarcoma of the lung with no evidence of extrapulmonary malignancy. CASE PRESENTATION: The patient is a 65-year-old Ethiopian female with history of Hypertension, presented to the Intensive care unit with massive hemoptysis, and dyspnea. Imaging revealed a large left lung mass measures 13.6 x 14.7 x 12.1 cm, causing severe loss of lung volume, and invasion of left mainstem bronchus. Lung biopsy showed fragments of cellular spindle cell proliferation with bland cytology and no increased mitotic activity. Immunohistochemistry was positive for Vimentin, CD99 and Epithelial Membrane Antigen. Findings were consistent with synovial sarcoma of the lung. She also had a bronchoscopy that showed narrowing of the left mainstem bronchus with oozing of blood from the bronchial wall. Screening for extrapulmonary primary site, showed no distant malignancy. Evaluation by cardiothoracic surgery for resection ensued. During hospital stay the patient received six cycles of radiation therapy to prevent further lung collapse. No further episodes of hemoptysis occurred however, she became febrile and received empirical antibiotics for obstructive pneumonia. Her general condition improved and was discharged to complete preoperative risk assessment for tumor resection as an outpatient. DISCUSSION: Synovial Sarcoma of the lung is a rare mesenchymal tumor accounts for 0.3 to 1.3 % of lung malignancies and slightly more common in men. There are four histologic subtypes: biphasic, monophasic spindle cell, monophasic epithelial cell, and poorly differentiated. Monophasic subtype has spindle component and differential diagnosis is vast, therefore immunohistochemistry is essential to differentiate monophasic subtypes of synovial sarcoma. Histology of the lung mass in our patient showed small fragments of spindle cell proliferation. On immunohistochemical study most synovial sarcomas will show cytokeratins and epithelial membrane antigen (EMA). In our case the tumor was positive for vimentin, CD99 and EMA. The overall prognosis is very poor. Unfavorable prognostic factors is tumor size (≥ 9 cm), neurovascular invasion, tumor necrosis, high mitotic activity and positive surgical margins. There is no specific recommended therapy, as studies remain largely inconclusive. When surgical resection is not possible, systemic chemotherapy can be used palliatively. CONCLUSIONS: The cornerstone of diagnosis of synovial sarcoma of the lung is pathological features and immunostaining. Surgical treatment is essential and prognosis is generally poor. Reference #1: Mankin HJ, Hornicek FJ. Diagnosis, classification, and management of soft tissue sarcomas. Cancer Control. 2005;12:5-21.[PubMed] DISCLOSURE: The following authors have nothing to disclose: Yordanos Habtegebriel, Maha Sulieman, Shima Ghavimi, Alem Mehari, Jennifer Carter No Product/Research Disclosure Information