Features of mammorgraphically negative breast tumours.

Mammography is a highly sensitive and specific technique in the diagnosis of breast cancer, but some tumours show no radiological features of malignancy. A total of 9.3 per cent of 323 consecutive patients with operable breast cancer had negative mammographic reports, and the clinical radiological and pathological findings in these cases are compared with those in the mammographically diagnosed group. Misinterpretation of carcinoma as a benign lesion and diagnostic difficulties in the dense dysplastic breast were found to be the main causes of error.