Intraoperative frozen section as a reliable ancillary technique in salivary gland surgery: A cross sectional study

Abstract

Background.Salivary glands tumours are uncommon, frequently benign lesions, prevalently located in the parotid gland (80%). Surgical decision making is based on the patient’s history, examination findings, imaging and fine needle aspiration (FNA). FNA is a pre-operative method with good ability in detecting malignancy.  During surgery, therefore, Frozen section (FS) can differentiate benign lesions from malignant tumours, to reduce incorrect treatments, to increase the chances of conservative surgery and to better evaluate surgical margins. The aim of our study is to demonstrate the accuracy of the FS procedure in surgery of the salivary glands and to stress the need for dedicated pathology units specialized in lesions of the oral cavity.Methods.  The study included 499 patients who underwent surgery from May 2005 and October 2014. An intra-operative frozen section procedure was done for 288 of them. All frozen sections were compared with the final results. The cases were classified by site, nature of the lesion and histotype, according to the WHO classification. Comparison was made between the intra-operative and the definitive diagnosis.Results.Of the 288 FS procedures, 259 were for neoplastic lesions, 199 of which benign and 60 malignant, and 29 for non-neoplastic lesions.  Of the 259 neoplastic FS results, 2 were shown to be false positives and 2 were diagnosed as different malignant types.  Of the 29 non-neoplastic FS results, 4 were false negatives.Conclusions.Our results showed that the accuracy of frozen section procedure is 98% for salivary glands tumors. The highest concordance between frozen section and the definitive diagnosis was for inflammatory processes (99%), pleomorphic adenoma (98%), Warthin’s tumor (97%) and malignant neoplasms (96%). In conclusion, based on these findings, frozen section of the salivary glands may be proposed as a routine procedure and should be used in decision-making.