Cytological study of fluid from breast cysts.

A series of 215 patients with breast cysts have provided 348 specimens of cyst fluid for cytological diagnosis. Only one of these specimens was reported positive for malignant cells and this patient had a carcinoma. Nine specimens were reported as suspicious, but none of these patients had or subsequently developed carcinoma. In 338 specimens cytology was negative. A total of 178 patients (294 specimens) was available for follow-up. Of these 2 proved to have carcinomas on immediate follow-up, i.e. a lump presisted after aspiration, and a further 2 patients developed cancers in the same breast, one 4 and the other 7 years after aspiration. We therefore conclude that the routine submission of breast cyst fluid for cytology is wasteful of time and resources.