evaluation of the value of core needle biopsy in the diagnosis of a breast mass

background: core needle biopsy (cnb) with histological findings is regarded as one of the most important diagnostic measures that make preoperative assessment and planning for appropriate treatment possible. the aim of this study was to determine the sensitivity and specificity of core biopsy results in our patients with benign and malignant breast lumps, especially for borderline breast lesions, by using a classification method. methods: in this study, 116 patients who were referred to the surgery clinic of ghaem hospital, mashhad university of medical sciences, mashhad, iran with breast lump and underwent diagnostic procedures such as mammography and ultrasound were selected. core needle biopsy (tru-cut #14 or 16) was performed. after that, excisional biopsy was done. the benign, malignant and unspecified samples obtained by core needle biopsy were evaluated with the samples of the surgical and pathological findings. then, false positive, false negative, sensitivity, specificity, and diagnostic accuracy of the core needle biopsy method were calculated. also, the national health service breast screening program (nhsbsp) classification was employed. results: the mean age of the participants in this study was 39±13.13 years and the mean tumor size was 2.7 cm. an average of 3.35 biopsies was taken from all patients. most of the pathology samples taken from cnb and excisional biopsy were compatible with invasive ductal carcinoma. of the b type classifications, b5 was the most frequent in both methods. borderline lesions b3 and b4 had a change in their category after surgery. about 2.5% of the samples in core biopsy were inadequate. skin bruising was the most common core biopsy complication reported. while, the most common complication of excisional biopsy was hematoma. accuracy, sensitivity, specificity, positive and negative predictive values of the core needle biopsy procedure compared with excisional biopsy was 95.5%, 92.6%, 100%, 100%, and 91.8%, respectively. conclusions: core needle biopsy has a high sensitivity and specificity with few side effects. borderline classifications need more evaluation to rule out cancers.