Pitfalls in frozen section interpretation: a retrospective study of palpable breast tumors

The use of frozen sections for purposes of diagnosis is recognized to involve a degree of uncertainty. A retrospective study of breast specimen frozen section diagnoses was undertaken in order to analyse the major pitfalls.

Hard copy files from our archives relating to symptomatic (palpable) breast specimens obtained between 1983 and 1996 were reviewed.

The review revealed 23 errors among the diagnoses on 2110 frozen specimens. Twenty-two of them were false-negative and 1 (a case of multiple intraductal papillomatosis with atypical ductal hyperplasia) was false-positive for malignancy. The factors contributing to the pitfalls were: 1) misinterpretation; 2) poor quality of the frozen sections (artifacts making the diagnosis difficult); 3) sampling errors during sectioning; 4) ignorance of the macroscopic features; 5) lesions difficult to interpret; 6) ductal carcinoma in situ as the only lesion in the specimen; and 7) sections not deep enough. Several of the factors sometimes occurred simultaneously.

Although the number of errors is relatively low, more stress should be placed on the preoperative diagnosis of breast lesions. Breast surgery frozen section should be used as rarely as possible for diagnostic purposes, despite the generally good diagnostic accuracy. However, it is reasonable to use frozen sections widely until the given preoperative diagnostic tools allow an appropriate preoperative workup, because it is the only way to keep histopathologists trained to interpret frozen sections.