Fine-needle aspiration cytology of mammary fibroadenoma: a comparison of ThinPrep® and cytospin preparations

Abstract

Mammary fibroadenoma (FA) is a lesion frequently sampled and diagnosed by fine-needle aspiration (FNA). Accurate cytologic diagnosis of this common benign lesion is important as this can lead to non-surgical, conservative management when breast imaging and clinical examination are concordant. In most instances, a confident diagnosis of FA is possible because of a characteristic cytologic appearance that includes hypercellularity, large epithelial cell groups, staghorn epithelial configurations, stromal fragments, and numerous background stripped nuclei. Nevertheless, FAs can be diagnostically challenging because of shared cytomorphologic features with other benign lesions and low-grade carcinoma. As such, FA is a well-recognized source of false results on FNA cytology. Furthermore, there are reports that newer thin layer cytopreparatory techniques, including the ThinPrep® (TP) system (Hologic Corp., Bedford, MA), alter the appearance of FA on FNA compared to conventional preparations and may compromise accurate cytologic diagnosis.