Breast pathology

Cellular pathology is a key component of the breast disease multidisciplinary team, representing the ‘gold standard’ in the diagnosis of breast cancer and providing information key to the determination of prognosis and management. Material may be obtained for pathological examination using fine needle aspiration (cytology) or core biopsy and surgical excision (histopathology). Common benign conditions include fibrocystic change, fibroadenomas, intraduct papillomas and radial scars. Carcinoma is by far the most common malignant tumour and may exist in in situ or invasive forms. The NHS Breast Screening Programme has resulted in the detection of less advanced breast cancers, for example in situ carcinoma and small, low-grade invasive carcinomas. A cellular pathology report for a breast excision specimen should include comments on the factors most pertinent to prognosis and management, such as tumour type, size, grade, and presence of vascular invasion and lymph node metastases. Assessment of adequacy of excision will inform decisions regarding further surgical excision and radiotherapy, while identification of lymph node metastases will prompt consideration for chemotherapy in suitable patients. Cellular pathology can also predict the likelihood of tumour response to hormonal manipulation and newer treatments such as trastuzumab.