Mesenchymal neoplasms of the head and neck: a cytopathologic analysis on fine needle aspiration

Introduction Fine-needle aspiration (FNA) is commonly used to diagnose mass lesions discovered in the head and neck (H&N). Soft tissue neoplasms (STNs) are less common than epithelial tumors in this anatomic zone and often cause diagnostic difficulty when encountered in routine practice. In this study, we examine the frequency of H&N STNs at our institution and describe their cytomorphologic characteristics and clinical correlates. Methods 115 FNA specimens from 115 patients with STN of the H&N region were identified (2005-2015) from archives of The Johns Hopkins University Hospital. When available, slides from these cases were reviewed and any corresponding clinical and radiologic data was evaluated. Results A total of 95 (83%) STNs were found to be primary to the H&N region and 20 (17%) were metastatic from distant sites. Of these 95 cases, 58 (61%) primary lesions were benign and 37 (39%) were malignant. The most common STNs were benign nerve sheath tumors, representing 40 (35%) cases: 30 schwannomas, 4 neurofibromas, and 6 were not further classified. The most aggressive neoplasms in terms of clinical outcome were leiomyosarcoma, Ewing sarcoma, synovial sarcoma, and chondrosarcoma. In 35 (60%) of the malignant cases and 25 (54%) of the benign cases a subsequent surgical resection was performed. Conclusions H&N can be involved by a wide range of primary and metastatic STNs. benign nerve sheath tumors are the most common STNs found on FNA in this region. Although not always definitively diagnostic, FNA of STNs can often provide a differential diagnosis that can help guide the need for an excision and/or further treatment.