Differential diagnosis between adenoid cystic carcinoma and pleomorphic adenoma of the minor salivary glands of palate.

Tumors arising from minor salivary glands of the palate may exhibit an overlap of clinical and biologic features that may produce diagnostic and therapeutic dilemmas. Surgical treatment can be very different, depending on the dimensions and malignant or benign nature of the tumors, and therefore should be planned on the basis of an accurate differential diagnosis. A retrospective analysis in 24 patients with pleomorphic adenoma and adenoid cystic carcinoma of minor salivary glands of the palate was performed to investigate the accuracy of fine needle aspiration cytology (FNAC) and biopsy with histology in the preoperative diagnosis. Preoperative diagnoses obtained with FNAC and biopsy were compared with findings of the definitive histopathologic examination performed on the resected mass. Correspondence between the preoperative diagnoses determined by FNACs and the definitive histopathologic results was observed in 22 of 24 cases, whereas a complete equivalence was found with regards to histology. In the analysis, FNAC was associated with 91.6% accuracy and an error rate of 8.4% in the diagnosis of pleomorphic adenoma and adenoid cystic carcinoma of the palate. From the results of the analysis, histologic examination is still the most accurate diagnostic tool in such tumors. FNAC can be considered in tumors of the head and neck regions that are difficult to reach by means of a common biopsy.