Understanding frozen section histopathology in Sinonasal and anterior skull base malignancy and proposed reporting guidelines

BackgroundIntraoperative frozen section histopathology (IFSH) in sinonasal and skull base surgery although widely used is not well studied.MethodsWe reviewed a database of sinonasal and anterior skull base tumors, between 1973 and 2019, and identified 312 suitable operative cases. Clinicopathologic data was collected and analyzed, in addition to descriptive data for histopathological reports classified as "ambiguous," or "limited/insufficient-quality/quantity."ResultsOverall, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for IFSH were 90.2%, 97.5%, 94.2%, 95.6%, and 95.2%, respectively. IFSH for adenocarcinoma, salivary carcinoma, and SCC all demonstrated a better clinical utility with a sensitivity of 90% or greater, while it was less than 90% for esthesioneuroblastoma, melanoma, and sarcoma. Other factors such as unclear reporting, poor quality specimens, or limited quality specimens were shown to lower diagnostic performance. Based on limitations identified, we proposed a novel IFSH reporting algorithm to improve IFSH in sinonasal and skull base surgery.ConclusionsIFSH is an accurate and clinically useful technique in sinonasal and skull base surgery patients; however, limitations exist.