Abstract
To evaluate accuracy of the intraoperative rapid frozen section diagnosis in assessing malignancy and margins, 71 frozen sections obtained at the time of excisional biopsy for oral squamous carcinomas were examined.
There were two false-negative cases when the frozen section diagnosis was compared with the final diagnosis on permanent sections, including five cases of carcinoma in situ and 66 cases of invasive squamous cell carcinoma. Thus 97.2 % of accuracy was found in the frozen section diagnosis. 78.7% of accuracy was found in grading histological differentiation and 80.0% accuracy in assessing pericancerous epithelial dysplasia. On the other hand, in grading the mode of invasion, 62.3% of accuravy was found between frozen section and permanent section. In diffuse type of mode of invasion, however, it should be kept in mind that it could be graded lower in the frozen section than the permanent section.
Local recurrence related to margin status in the permanent sections but not in the frozen sections. However, frozen section diagnosis is useful to obtain surgical-free margins.
