Find in Library

<p>Abstract</p> <p>We report five cases of primary synovial sarcomas arising in the parapharyngeal space. The patients were all men with a median age of <it>35</it> years (range <it>22</it> to <it>41</it> years). The tumors were non-encapsulated solid masses ranging from <it>2.0</it> to <it>6.6</it> cm in size. Histologically, three cases were biphasic subtype, and the other two cases were monophasic subtype. Immunohistochemically, the tumor cells were strongly positive for bcl-2 and CD99, partly positive for CK and EMA, and negative for CD117, CD34, SMA and desmin in all five cases. S-100 protein was detected in one case. The presence of an <it>SYT–SSX1</it> and/or <it>SYT-SSX2</it> gene fusion resulting from <it>t(X;18)</it> was demonstrated from paraffin blocks by reverse transcriptase polymerase chain reaction in five cases. All five patients received tumor radical excision and postoperative radiotherapy, and two patients with pulmonary metastasis received additional chemotherapy. Follow-up data revealed that two patients with tumor size <<it>5</it> cm were alive without disease for <it>54</it> and <it>57</it> months, one patient with tumor size <<it>5</it> cm was alive with pulmonary metastasis for 78 months, and two patients with tumor size ><it>5</it> cm died of disease <it>26</it> and <it>37</it> months after the diagnosis, respectively. Primary parapharyngeal synovial sarcoma is a rare variant that occurs more frequently in males than females. Accurate diagnosis depends on morphologic and immunohistochemical examination and proper molecular analysis. The prognosis is relatively good in those patients whose tumor size is less than <it>5</it> cm.</p>