Discordance of intraoperative frozen section analysis with definitive histology of sentinel lymph nodes in breast cancer surgery: complementary axillary lymph node dissection is irrelevant for subsequent systemic therapy.

BACKGROUND: In breast cancer surgery, intraoperative frozen section (FS) analysis of sentinel lymph nodes (SLNs) enables axillary lymph node dissection (ALND) during the same operative procedure. In case of discordance between a "negative" FS analysis and definitive histology, an ALND as a second operation is advocated since additional lymph node metastases may be present. The clinical implications of the subsequent ALND in these patients were evaluated. MATERIALS AND METHODS: Between November 2000 and May 2008, 879 consecutive breast cancer patients underwent surgery including sentinel lymph node biopsy (SLNB) with intraoperative FS analysis of 2 central cuts from axillary SLNs. Following fixation and serial sectioning, SLNs were further examined postoperatively with hematoxylin and eosin (H&E) and immunohistochemical techniques. For patients with a discordant FS examination, the effect of the pathology findings of the subsequent ALND specimen on subsequent nonsurgical therapy were evaluated. RESULTS: FS analysis detected axillary metastases in the SLN(s) in 200 patients (23%), while the definitive pathology examination detected metastases in SLNs in another 151 patients (17%). A complementary ALND was performed in 108 of the 151 patients with discordant FS. Additional tumor positive axillary lymph nodes were found in 17 patients (16%), leading to "upstaging" in 7 (6%). Subsequent nonsurgical treatment was adjusted in 4 patients (4%): all 4 had more extensive locoregional radiotherapy; no patient received additional hormonal and/or chemotherapy. CONCLUSION: Discordance between intraoperative FS analysis and definitive histology of SLNs is common. In this selection of patients, a substantial proportion had additional lymph node metastases, but postsurgical treatment was rarely adjusted based on the findings of the complementary ALND.

Accuracy of frozen section diagnoses of breast lesions after introduction of a national programme in mammographic screening.

AIMS: By introducing mammography screening programmes, the size of the detected breast lesions became smaller and the histopathological interpretation problems greater. The study's aim was to analyse the risks and possible limitations of the frozen section method. METHODS AND RESULTS: Frozen section consultations of breast lesions (n=559) 2 years before and 6 years after launching a national mammographic screening programme in 1992 were evaluated in regard of the benign/malignant ratio, tumour size, preoperative frozen section results and final permanent section diagnoses. The breast frozen section examinations of 1990 compared with those from 1998 declined from 70.7% (299/423) to 62.2% (260/418) (P < 0.01), the benign/malignant ratio from 1.09 to 0.54 (P < 0.0001), the rate of the conclusive, correct frozen section diagnoses from 96.3% to 91.9% (P < 0.03). The sensitivity dropped from 92.3% to 87.6%, the negative predictive value from 95.7% to 88.3%, whereas the negative likelihood ratio rose from 0.08 to 0.12. The 'small' (< or = 10 mm) invasive breast carcinomas increased from 14.2% to 22.3% (P < 0.01) and the 'in situ' carcinomas from 2.1% to 6.6% (P < 0.05). CONCLUSIONS: The declining sizes of breast tumours (< or = 10 mm), especially from radiologically detected lesions and sometimes without a macroscopic correlate, create new limitations and changing indications in the histopathological interpretation. Considering the performance of new diagnostic methods (i.e. large core needle biopsies), frozen sections of surgical specimens should not be the primary diagnostic procedure for breast lesions and should be performed only after other preoperative methods have failed.