Unusual presentation of poorly differentiated primary pulmonary synovial sarcoma (PD-PPSS) diagnosed by EBUS-TBNA with cytogenetic confirmation-A diagnostic challenge

Synovial sarcoma: cytopathology of 51 cases highlighting the application of ancillary molecular testing

INTRODUCTION

Among sarcomas, synovial sarcoma (SS) is defined by its unique SS18 cytogenetic translocation. Fine needle aspiration (FNA) biopsy is in a key position to exploit this uniqueness for diagnostic purposes.

MATERIALS AND METHODS

Our cytopathology files were searched for examples of SS with histopathologic verification. FNA biopsy, imprint smears, and core needle biopsy (CNB) were performed using standard techniques.

RESULTS

Fifty-one cases from 49 patients (male/female ratio, 1:1; age range, 12-79 years; mean age, 40 years) met the inclusion criteria. Of the 51 cases, 44 (86%) were FNAs, 6 were cytology imprints, and 1 was pleural fluid. Eleven aspirates had concurrent CNB. All cases had tissue confirmation. The biopsy sites included extremities (n = 24; 47%), trunk (n = 12; 24%), lung (n = 8; 16%), head or neck (n = 6; 12%), and pleural fluid (n = 1; 2%). The aspirates were from primary (n = 36; 71%), metastatic (n = 12; 24%), and recurrent (n = 3; 5%) neoplasms. The cytologic diagnoses were SS (69%), suspicious for SS (12%), malignancy (10%), spindle cell neoplasm (4%), and malignancy other than SS (6%). In general, smears and imprints contained dense cell aggregates and single cells composed of a monotonous population having fusiform, rounded, or ovoid banal nuclei and scant cytoplasm. Poorly differentiated SS showed both large epithelioid cell and small cell cytomorphology. When performed, SS18 immunohistochemical and genetic testing was positive in all 19 FNA and 3 CNB cases.

CONCLUSIONS

When coupled with appropriate ancillary testing, FNA biopsy allows for a specific, accurate diagnosis of SS in most cases.

[A Case Report of Primary Pulmonary Synovial Sarcoma with Postoperative Multiple Metastases Treated with Apatinib]

原发性肺滑膜肉瘤是一种起源于原始间叶细胞的罕见肺部恶性肿瘤，其临床特点包括生存期短、预后差，目前国内外仅有少数相关报道。近年来，靶向治疗的发展为肿瘤患者带来显著的获益。甲磺酸阿帕替尼是我国自主研发的小分子血管内皮生长因子受体-2（vascular endothelial growth factor receptor-2, VEGFR-2）抑制剂，可高度选择性地抑制VEGFR-2酪氨酸激酶活性，阻断血管内皮生长因子（vascular endothelial growth factor, VEGF）结合后的信号通路，从而强效抑制肿瘤血管的生成，目前已在多种瘤种中显示出确切的抗肿瘤效果和可接受的毒副反应。本文介绍了阿帕替尼治疗原发性肺滑膜肉瘤术后多发转移1例，以期在临床工作中为医生提供新的治疗思路。