Introduction/Background The Bi-Rads (Breast Imaging Reporting and Data System) classification of the ACR (American College of Radiology) is the recommended system for grading radiological images for breast cancer screening, and allows for appropriate action to be taken according to this classification from ACR 1 to ACR 5 depending on the probability of malignancy.

The ACR IV lesion corresponds to an undetermined or suspicious abnormality with a probability of malignancy of 10 - 90%. This disparity´ prompted our study.

Methodology This is a retrospective study of 200 patients spread over 6 years, from 2017 to 2023, conducted in the department of gynecology-obstetrics I of the Hassan II Hospital Center of Fez.

Results We noted´ a clear predominance of benign lesions with a rate of 72% versus 20% of malignant lesions and only 8% were intermediate. Adenofibroma is the most found histological finding with 40% of cases, infiltrating ductal carcinoma remains the leader of malignant lesions with 15% of cases. 72% of our patients underwent surgery, 69% of whom underwent lumpectomy and 19% mastectomy.

Conclusion Through a review of the literature, our results seem to agree with those of other studies. However, due to the high number of unnecessary surgical interventions, a sub-classification into ACR4a, b and c seems more appropriate.

Disclosures Breast pathology seems to affect the female population at all ages with a peak in frequency between 40 and 50 years.

The palpation of a nodule is the first reason for consultation in our patients with 80% of cases. All our patients have benefited from ultrasound and mammography followed by anatomopathological evidence by different techniques.