Cytomorphologic Features of Metastatic Sarcomas in Body Cavity Fluids Overlaps with Other Common Malignancies

Background: Sarcomas rarely involve body cavity fluids, accounting for less than 5% of all malignant effusions. Most existing literature describes the cytomorphologic features sarcomas in setting fine-needle aspiration and/or touch preparations targeted tissue biopsies. The objective this study was to investigate morphologic spectrum displayed by metastatic fluid specimens. Methods: pathology database at our institution searched sarcoma cases involving pleural, pericardial, and peritoneal fluids between 1994 2019. Their clinical presentations cytopathologic were reviewed. Immunohistochemical (IHC) stains performed on cellblock sections DAKO Autostainer (DAKO, Carpinteria, CA). Results: Nineteen identified, including 14 females 5 males, ranging age from 4 88 years old (median: 28.6 years). sites 11 7 peritoneal, 1 pericardial. There rhabdomyosarcomas, osteosarcomas, Ewing sarcomas, 2 endometrial stromal leiomyosarcomas, clear cell sarcoma, liposarcoma. Malignant pleural effusion first presentation only (both alveolar rhabdomyosarcomas). Three different patterns seen: 1-glandular pattern showing large epithelioid cells with vacuolated cytoplasm (3 cases), a 2-pleomorphic single-cell highly atypical (6 cases); 3-small round blue small intermediate-sized dyscohesive high NC ratio (10 cases). Conclusion: exhibited often overlaps other common malignancies such as adenocarcinomas, poorly differentiated carcinomas, lymphomas. Keywords: Sarcoma; Cytology; Peritoneal.