Objectives Estimating the value of the biopsy of non-palpable injuries in diagnosis of breast cancer. Oncological Gynecology Service, Hospital Nacional Edgardo Rebagliati Martins, Lima-Peru 2018.

Methods Observational, transversal, retrospective and descriptive study. It analyzes a consecutive series of 99 women with non-palpable injuries biopsy from the service of Oncological Gynecology at the Hospital Nacional Edgardo Rebagliati Martins from July 2017 to July 2018. All women have had a previous radiological diagnosis expressed in BI-RADS, with non-palpable mammary findings suspected of malignancy. All biopsies have had histopathological diagnosis.

Results The rate of breast cancer detection non-palpable injuries using metal guide has been 32% (21% infiltrating cancer and 11% cancer in situ).

The positive predictive value of the Bi-rads 4a has been 38%, 21% Bi-rads 4b, 55% 4c and 60% Bi-rads5.

Metal guided biopsy is an effective surgical technique in the diagnosis of non-palpable breast cancer.

As the mammographic extension increases, they also increase (in a mild form): Age, Bi-rads score, cancer stage, nuclear grade and surgical margin commitment (No statistical significance).

As the size of the surgical piece increases, the previous associations disappear or are barely perceptible (No statistical significance).

Conclusions The biopsy of non-palpable lesions in the diagnosis of breast cancer in our hospital is within international stardards.