Challenges in the interpretation of breast core biopsies

The aim of core needle biopsy (CNB) is to diagnose a breast abnormality prior to open surgical excision. The radiology-pathology correlation helps in interpretation of pathologic findings and is greatly assisted by specimen radiology of all cores performed for calcifications, separation of cores containing calcification from those without, and the availability of the specimen radiograph to the pathologist at the time of reporting. The nature of the imaging abnormality should also be clearly conveyed. CNB is processed in a routine manner for paraffin embedding with preservation of sufficient material in the block for further studies as needed. Possible pitfalls include the loss of calcifications at the time of section cutting, calcium remained in the formalin of the specimen container, and failure to recognize calcium oxalate deposition in the CNB. The challenges of CNB interpretation are complicated by the availability of only limited material, but are generally similar to those encountered in open surgical excision specimens. This discussion focuses on high-risk lesions and lesions that raise management issues. The most prudent approach for the pathologist is to provide sufficient information to prompt a surgical excision without overdiagnosing the lesion, thus placing the patient into the appropriate therapeutic algorithm.