Fine needle aspiration diagnosis of non-epithelial lesions of the major salivary glands

Fine needle aspiration (FNA) is an accurate, reliable and cost effective procedure for the diagnosis of epithelial salivary gland lesions. The role of FNA is less clear in non-epithelial (mesenchymal and lymphoproliferative) lesions. We report our experience in which we reviewed 242 cases of salivary gland FNA performed during 1999-2013, from amongst which we identified 7 mesenchymal and 12 lymphoid/lymphoproliferative lesions. The cytology diagnoses were categorized into 3 groups: Group I) benign neoplasms (7 cases); Group II) benign lymphoid lesions (7 cases); Group III) malignant tumors (5 cases), all were non-Hodgkin lymphomas. Of the 19 cases, 9 (47%) had tissue biopsy for comparison. A high degree of diagnostic concordance was noted between FNA and tissue biopsy (67%, 6 out of 9 cases). Causes of the false negative FNA cases were explained in details and discussed. In summary, non-epithelial salivary gland lesions are uncommon. The differential diagnoses are widely scattered, including benign and malignant neoplasms. Adequate sampling and close communication between clinicians and cytopathologists are critical to reach a definitive conclusion. Ancillary tests (immunohistochemical stains, flow cytometry) along with clinical and radiological findings help to reach the definitive diagnosis in some cases.