Case Report Primary Pulmonary Synovial Sarcoma: A Very Rare Presentation Ekrem Cengiz Seyhan, 1 Sinem Nedime Sokucu, 2 Gulsah Gunluoglu, 2 Nurdan Simsek Veske, 2 and Sedat Altin 2 1 Department of Chest Diseases, Medical Faculty, Medipol University, 34214 Istanbul, Turkey 2 Yedikule Teaching Hospital for Chest Diseases and horacic Surgery, Istanbul, Turkey Correspondence should be addressed to Ekrem Cengiz Seyhan; drekremcs@yahoo.com Received 4 April 2014; Revised 24 June 2014; Accepted 9 July 2014; Published 3 August 2014 Academic Editor: Akif Turna Copyright © 2014 Ekrem Cengiz Seyhan et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Synovial sarcoma (SS) is a rare tumor originating from mesenchymal tissue and accounting for approximately 5–10% of all sot tissue sarcomas. A rare case of primary pulmonary SS in an asymptomatic 18-year-old man admitted to our hospital for investigation of a 6 × 6.5 cm, oval-shaped, well-delineated pleural based peripheral mass in the let lower lobe in his thorax CT is presented. Let lower lobectomy was done. Immunohistochemically, tumor cells were positive for cytokeratin, epithelial membrane antigen (EMA), and vimentin so that the histopathological diagnosis was compatible with biphasic spindle cell type SS in the lung. 1. Introduction Synovial sarcomas (SS) account for nearly 5–10% of all sot tis- sue sarcomas [1, 2]. Clinically it is presented as a palpable and painful sot tissue mass. SS not only occurs predominantly in the large joints of the extremities, but also could occur in neck, tongue, larynx, mediastinum, esophagus, heart, lung, abdomen wall, small intestine, mesentery, vessels, and retroperitoneum. horacic involvement of the SS in the liter- ature was reported to be very rare [1, 2]. Primary pulmonary and mediastinal SS is an aggressive tumor sharing common histological features with sot tissue SS [3, 4]. SS, although rare, is a primary pulmonary and mediastinal neoplasm with distinctive histology. It’s rare occurrence in this region cause to be overlooked in the diferential diagnosis. Recognizing radiological, histopathological, and molecular properties of the SS is very important for appropriate treatment. 2. Case Report An 18-year-old man was referred for investigation of a periph- eral opacity in the let lung lower lobe, which was discovered incidentally on a chest radiograph. he patient is a student and has a 6-pack/year smoking history. He was in good general health and well nourished. Physical examination was normal. he results of blood tests and standard biochemical tests were normal. Posteroanterior chest X-ray (Figure 1) revealed a well- demarcated 6 cm in diameter peripheral opacity in the let lower lobe near by the diaphragm. Chest computed tomogra- phy (CT) conirmed a 6 × 6.5 cm, oval-shaped, well-delineat- ed pleural basedperipheral mass in the let lower lobe, in sot tissue attenuation and with no evidence of mediastinal or axillary adenopathy. Cyst hydatid hemagglutination was negative. Fiberoptic bronchoscopy showed no endobronchial pathology. Bronchoalveolar lavage and bronchial brushing specimens, obtained during bronchoscopy, were negative for malignancy. horax CT angiography was taken to reveal vascular relation of the tumor. Heterogeneous contrast enhanced 6,5 × 4,5 × 6 cm mass lesion located at posterobasal segment of the let lung lower lobe was seen (Figure 2). No vascular relation was detected. he CT-guided ine needle aspirate from the mass revealed roundcell tumor. Full body bone scintigraphy and cranial magnetic resonance imaging (MR) taken for metastasis evaluation were normal. Let posterolateral thoracotomy was performed. At lower lobe of the lung a big tumor at posterobasal segment was observed. he tumor was under the visceral pleura. Subse- quently let lower lobectomy was done with dissection of Hindawi Publishing Corporation Case Reports in Pulmonology Volume 2014, Article ID 537618, 3 pages http://dx.doi.org/10.1155/2014/537618