Advancing Education, Research, and Quality of Care for the Head and Neck oncology patient.
Program Number: B309
Session Name: Poster Session
Comparison of Biopsy to Intraoperative Examination for Grading of Salivary Gland Neoplasms
Spencer Roark, DDS1; Rachelle Wolk, DDS, MBA2; Hassan Arshad, MD1; Andrea Olivas, MD1; Nicole Cipriani, MD1; 1The University of Chicago; 2New York University College of DentistrySalivary gland neoplasms are subject to fine needle aspiration (FNA) or core biopsy for guiding therapy. Resection specimens are occasionally sent for intraoperative frozen section for definitive grading (benign/low grade versus high grade) such that a neck dissection will be performed for high grade carcinomas or adenoid cystic carcinomas (AdCC). This study aims to correlate the grade of salivary lesions on FNA/core biopsy, intraoperative examination, and final histologic examination to determine if these neoplasms can be effectively graded on biopsy and if the addition of frozen section significantly alters patient management.
91 patients underwent biopsy and resection with intraoperative frozen section: 85 had FNA; 6 had core biopsy. Diagnoses were stratified: low grade (benign, stated low grade, known low grade carcinoma); high grade (AdCC, stated high grade, known high grade carcinoma); basaloid (differential including AdCC); or unknown. Reason for frozen section and subsequent intraoperative management were recorded.
Results are in Figure 1. There were 4 significant grade discrepancies (4%, low vs high grade) and 1 minor discrepancy (low vs intermediate grade). Reason for frozen in most cases was for diagnosis/grade confirmation (83), clinical concern for high grade malignancy (3), or margin status (5). Lateral neck dissection was performed in 12 patients: 10 high grade, 1 ungraded but clinically aggressive, 1 low grade on frozen. Only 1 patient with a high grade frozen diagnosis (AdCC) did not undergo neck dissection due to overall unresectability.
Concordance between biopsy/frozen/final grade was achieved in 96%. Basaloid neoplasms were the most challenging: 50% AdCC and 50% low grade neoplasms (pleomorphic adenoma, basal cell adenoma/adenocarcinoma, epithelial-myoepithelial carcinoma). Frozen was useful in grading cases with an uncertain biopsy grade or a basaloid diagnosis, but did not add information in cases with an implied (i.e. pleomorphic adenoma) or stated biopsy grade. Attempt should be made to render a grade (low versus high) on FNA/core biopsy of salivary lesions due to high concordance rates with final grade. Diagnosis of high grade carcinoma or AdCC did result in neck dissection. Evaluation for MYB::NFIB fusion could be considered in basaloid cases. Frozen section of neoplasms with a biopsy grade should be discouraged as intraoperative examination does not add additional information.
