Role of Frozen Biopsy in Glottic Premalignant Lesions.

Frozen biopsies are frequently used for decision making during surgery. This study aimed to evaluate the efficacy of frozen biopsy for guiding decision making before laser excision of glottic premalignant lesions. One hundred patients with 119 laser excisions were included in this study and reviewed retrospectively. After frozen biopsy, type I or II cordectomy was performed and the frozen result and final pathology of the excisional specimen were compared. The positive predictive value of frozen biopsy when the diagnosis is benign or malignant was relatively high (80.8 and 88.9 %, respectively) but the positive predictive value of a dysplasia or carcinoma in situ result was quite low (18.2 and 16.7 %). Under-diagnosis was frequent for dysplasia or carcinoma in situ (69.7 and 83.3 %). In particular, for lesions with suspicious features, lesions with dysplasia or carcinoma in situ had a much higher rate of under-diagnosis (81.8 and 100 %). Frozen biopsy was not reliable because the overall coincidence rate between final pathology and frozen biopsy was 63 %. Although a frozen biopsy result of a benign or malignant result was reliable, a dysplasia or carcinoma in situ result on frozen biopsy had a high risk of being an under-diagnosis.