Percutaneous core biopsy of palpable breast lesions: accuracy of frozen section histopathological exam in the diagnosis of breast cancer.

Objective: to evaluate the accuracy of frozen section histopathology from fragments of tissue obtained by percutaneous core needle biopsy of palpable tumors in the diagnosis of breast cancer.

Methods: a cohort study was performed on 57 patients with palpable tumors and suspected breast cancer undergoing percutaneous thick needle core biopsy. The fragments were analyzed by the same pathologist.

Results: frozen section diagnosed 16 benign cases (28.6%) and 40 malignant (71.4%), whereas paraffin showed that 15 were benign (26.8%) and 41 malignant (73.2%). Histopathological examinations were concordant in 55 cases and there was one false-negative (6.2%). Statistics rates were: negative predictive value of 93.8%, positive predictive value of 100%, no false-positive (0%), one false negative (6.2%), specificity of 100%, sensitivity of 97 6%; observed agreement = 98.2%; expected agreement = 59.9%, Kappa = 0.955 [ 95% CI = 0.925-0.974, p < 0.01 ].

Conclusions: frozen section histopathological findings showed excellent correlation with the findings by the technique in paraffin in the fragments of palpable breast tumors obtained by thick needle percutaneous core biopsy (98.2% accuracy). Therefore, in these patients, it was possible to anticipate the diagnosis, staging and the breast cancer treatment planning.