Clear cell carcinoma of salivary gland. Clinicpathologic study of 11 cases

Abstract

Abstract Introduction. Clear cell carcinoma of salivary gland is a rare malignant neoplasm that accounts for less than 1% of salivary gland carcinomas. This term is common in many carcinomas with clear cells; however, it is more specific to hyalinizing clear cell carcinoma. Objective. This research aimed to evaluate histopathological, immunohistochemical, biomolecular, and clinical aspects of clear cell carcinomas of salivary gland cases diagnosed between 1997 and 2018. Materials and Methods. Histological sections, immunohistochemical reactions for cytokeratins 7 and 14 (CK7 and CK14), p63 protein, S-100 protein, and smooth muscle actin (SMA) were assessed, and real-time molecular polymerase chain reaction (RT-PCR) testing was performed to investigate the expression of the EWSR1-ATF1 fusion gene. Results. Eleven lesions with histological and immunohistochemical characteristics of clear cell carcinoma of salivary glands were found, 81.81% occurred in women, 77.77% in white people and the mean age was 56.42 years. The most affected regions were palate and buccal mucosa (36.36% of cases in each of these regions). Histologically, nine cases had hyalinization; neural invasion and necrosis were present in 6 and 2 of the cases, respectively. All cases were positive for periodic acid-Schiff (PAS) and expressed p63 protein and cytokeratins 7 and 14. In the PCR molecular test, 6 lesions showed EWSR1-ATF1 fusion gene. Conclusion. Clear cell carcinoma of salivary glands is more prevalent in women aged between 50 and 60 years. Histology associated with immunohistochemistry often closes the diagnosis. Molecular tests should be used as an aid in diagnosis.