Outcome of surgery for non-palpable mammographic abnormalities

Four hundred and ninety-three women underwent 515 localization biopsies for non-palpable mammographic abnormalities. The mammographic abnormality was located with a hooked wire in 509 cases. Specimen radiology was performed on all excised tissue. The mammographic abnormality was visualized in the first piece of tissue excised in 402 (78.1 per cent) cases and complete excision was achieved in 476 (92.4 per cent). A palpable nodule was removed in 38 (7.4 per cent) cases and in 17 (44.7 per cent) was shown to contain a carcinoma. The mammographic abnormality was missed in 14 (2.7 per cent) cases or only partly excised in 13 (2.5 per cent). Overall 144 (28.0 per cent) localization biopsies were malignant. The mammographic abnormality was not visualized on the specimen radiograph more frequently in women aged under 55 years, in women with dense breast (Wolfe grade DM or DY) or in those whose mammographic abnormality contained only microcalcification. The 27 women in whom the mammographic abnormality was not visible on the specimen radiograph underwent repeat mammography 2 months later. Only two women required a further localization biopsy and the mammographic abnormality was recovered in the first piece of tissue excised. Women with a carcinoma underwent mastectomy or wide local excision, and residual carcinoma at the localization biopsy site was found in 64 (44.4 per cent) cases. Oestrogen receptor analysis by ligand binding assay was possible in only 71 (49.3 per cent) carcinomas. If the specimen radiograph does not show the mammographic abnormality within pieces of tissue excised and there is no palpable nodule it may be best to conclude the biopsy. In this series these missed lesions were usually benign. Only rarely is a second localization biopsy required and this is performed without difficulty.