FALSE-POSITIVE REPORTING IN BREAST FINE-NEEDLE ASPIRATION CYTOLOGY - INCIDENCE AND CAUSES

The diagnosis of breast cancer is often made by fine-needle aspiration cytology (FNAC). Over a 4-year period, there were 1104 cases reported as carcinoma by FNAC at the Royal Marsden Hospital and in four of the se the diagnosis was subsequently proven to be benign. This is an inci dence of 0.36% and represents a positive predictive value in the serie s of 99.6%. The benign conditions that led to false positive cytodiagn osis were radiation-induced changes, granulomatous mastitis, and fibro adenoma. Although the reliability of FNAC of breast is high, clinician s should be aware of the limitations and pitfalls.