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.

Diagnostic dilemmas and pitfalls in ThinPrep®cytology of breast fine needle aspiration biopsy:

“…It has been suggested that TP alters the classic cytological appearance of fibroadenomas, making the diagnosis of this entity cumbersome. Ly et al observed marked hypercellularity and reduced number of background stripped nuclei in the TP samples compared with the cytospin preparations of fibroadenomas . The homogenization step in TP, which is intended to disperse debris and promote a random distribution of cells, disrupts the cellular architecture and might be accountable for the reduction of epithelial clusters with staghorn configuration .…”

“…Ly et al observed marked hypercellularity and reduced number of background stripped nuclei in the TP samples compared with the cytospin preparations of fibroadenomas . The homogenization step in TP, which is intended to disperse debris and promote a random distribution of cells, disrupts the cellular architecture and might be accountable for the reduction of epithelial clusters with staghorn configuration . Michael et al suggested that stripped nuclei (myoepithelial cells) may be pulled through the TP filter during processing with a resulting reduction in their number .…”

Breast fibroadenoma: diagnostic performance of gray-scale sonography and sonoelastography: a prospective observational study

“…In most cases a confident diagnosis is possible with this. 17 On sonography, the major descriptive criteria for 100 of the imaged biopsied fibroadenomas were a solid mass lesion (83%), a round (48%) or oval (37%) shape, a smooth contour (75%) and 25% with irregular margins. These latter lesions were interpreted as suspicious for malignancy, although breast mass biopsies confirmed benign.…”

Adequacy of Fine-Needle Aspiration Cytology for Breast Lesions: The SurePath® Liquid-Based Technique versus Conventional Smears

“…Further studies should be conducted that include more cases, adequate controls for the FNA techniques and ‘spit samples'. Ly et al [15] studied the LBC technique, ThinPrep, for fibroadenomas and found that all of the characteristic cytomorphologic features were preserved and that the classic features of the lesions were similar to those observed with Cytospin™ preparations. Kontzoglou et al [16] also used the ThinPrep technique and reported that LBC techniques have 2 advantages over conventional methods.…”