Evaluation of Frozen Section Diagnosis of Parotid Gland Tumors.

A retrospective study is presented comparing the results of 167 frozen section diagnoses of surgical extirpated parotid gland tumors with permanent-section diagnoses. Percentages of correct diagnosis for malignancy (cases correctly classified as benign or malignant tumors) and of correct diagnosis for histopathology (cases in which frozen section diagnosis and permanent-section diagnosis were identical) were calculated. Percentages of correct diagnosis for malignancy in all cases, benign cases, and malignant cases were 98.8%, 99.3%, and 95.8%, respectively. Percentages of correct diagnosis for histopathology in all cases, benign cases, and malignant cases were 94.0%, 97.2%, and 75.0%, respectively. These results are superior to the previous reports both of frozen section diagnosis and of fine-needle aspiration biopsy diagnosis although the data for histopathological diagnosis in malignant tumors are average compared to previous reports. We conclude that diagnoses of most parotid gland tumors based on frozen section examination are reliable and accurate, but caution should be exercised in malignant tumors diagnosis.