How many tests are required in the diagnosis of palpable breast abnormalities?

Palpable breast nodules in 143 patients attending our primary diagnosis breast clinics were assessed by clinical examination, needle cytology, mammography, ultrasonography and magnetic resonance imaging (MRI). The diagnostic accuracy of all test combinations was compared with the final diagnosis of malignant or benign disease. Two-test combinations increased the sensitivity of diagnosis over that of the individual tests to between 93% and 100% except for MRI/mammography and MRI/cytology. The combinations of three or more tests increased the sensitivity further, but at the expense of an increased false-positive rate. MRI does not appear to have an important role in the primary diagnosis of breast cancer. Mammography is necessary because of the possibility of occult or multifocal disease. Clinical examination was associated with a high false-positive rate. The combination of cytology and ultrasound was best at correctly diagnosing malignancy, but in this series only 42% of patients underwent ultrasound examination. The role of breast ultrasound together with needle aspiration cytology for the diagnosis of malignancy in palpable breast nodules deserves further evaluation.