Classification system for the categorisation of breast needle core biopsy (NCB)
| Biopsy category | Description of NCB |
|---|---|
| *Our modifications to the suggested classification system from St Bartholomew's Hospital. The B2r (benign but requires clinical/radiological review) category is an additional category and the B3 category has been subdivided into B3a and B3b. | |
| †We included biopsies showing normal/benign tissue within the B1 category if the biopsy was performed because of microcalcifications but no microcalcifications were identified within the biopsy material. | |
| B1 | Unsatisfactory or normal tissue† |
| B2r* | Benign but uncertain whether representative |
| B2 | Benign representative lesion |
| B3a* | Essentially benign lesions that may be associated with malignancy—for example, radial scar/complex sclerosing lesion, intraduct papilloma |
| B3b* | Lesions showing atypical features and strongly associated with malignancy, such as atypical ductal hyperplasia (ADH) |
| B4 | Malignant, but diagnosis cannot be categorically made owing to a technical artefact or the small size of the biopsy |
| B5 | Malignant, either in situ or invasive |