Frozen-section diagnosis in surgical pathology: a quality assurance study

In a quality assurance study we reviewed one thousand four hundred and forty-three consecutive frozen sections performed at department of pathology, VGH-TC from June 1995 to July 1996. The diagnostic accuracy was 92.6%. The diagnosis was deferred in sixty-eight cases (4.7%). False positive for malignant tumor was made in two cases (0.14%) and false negative diagnosis for malignancy in thirty-seven (2.56%). The inaccurate diagnosis was mainly in samples taken from the brain, female breast, and thyroid. Incorrect diagnoses were mainly due to interpretation of the pathologic findings (71.8%), followed by gross sampling (15.4%) and microscopic sampling (12.8 %). Some of the lesions were difficult to diagnose even in permanent sections. Technical skill and diagnostic expertise are essential for frozen diagnosis. We suggest that an accuracy survey of frozen section be periodically performed in every pathology department as part of its quality assurance program.