Introduction/Background The reliability and safety of imaging-guided hook wire localization(HWL) biopsy for non-palpable lesions in early breast cancer diagnosis has been established.we aim to evaluate the reliability of this approach for subclinical lesions and to assess sensibility and specificity of preoperative imaging evaluation.

Methodology We retrospectively analyzed 34 patients who underwent a HWLsurgical excision for non-palpable breast lesions at Salah Azaiez Institut(2019 to April 2023). Pathological examination was considered as a gold standard.

Results Hhistory of breast cancer was found in 9 cases.

Radiological classification was as follows:BIRADS5 in 3 cases(8.8%), BIRADS4 in 30 cases(88.23%) and BIRADS0 in 1 case.

All surgical specimens were carried out under mammographic guidance.Systematic cavity margins were performed. Frozen section examination was not indicated.

The overall malignancy rate was 29.4%(10cases) including 7 cases of carcinomas in situ(CIS), 2 invasive ductal carcinomas(IDC), 1 invasive lobular carcinoma(ILC); found in 40% of cases on both lumpectomy and cavity margins.

The diagnosis of malignancy was reported in 9 patients (42.85%) of 21 BIRADS4 cases(7 CIS, 1DCI, 1 LCI) and in 1 case among 3 BIRADS5 lesions(IDC).

In BIRADS 4 we found:4A(4/11.8%) 4B(19/55.9%)and 4C(7/20.6%). The number of positive lesions were nine : 1(IDC), five(CIS) and three: 2 CIS and 1 ILC respectively.

Concerning benign lesions, the most frequent lesions found were epithelial hyperplasia and fibrocystic disease in six cases(28.6%) respectively followed by complex mastopathy in four cases(19%) and fibroadenoma in three cases(14.3%).

In 2 lesions, surgical excision was not contributory.

Microcalcifications were found in the surgical specimen in all diagnosed malignant lesions and in 15 cases(68%) of benign lesions.

The sensitivity, specificity, VPP and VPN of mammography findings was respectively 90%, 75%, 40% and 75%

Conclusion Wire-free localization systems have been developed recently to counter some disadvantages of HWL(risk of migration).Future studies will be required to determine the long-term effects of using these innovative procedures.

Disclosures the authors have nothing to dicolose.