Significance of bizarre cells in cervical screening liquid-based cytology: A prospective study of 15 cases.

OBJECTIVE: The aim of this study was to assess the significance of bizarre cells (cells of squamous origin with a superficial squamous cell-type cytoplasm and characterised by multinucleation that produces bizarre nuclear shapes) in liquid-based cytology (LBC) Papanicoaou (pap) smears with clinical and histological follow-up correlation.

METHODS: Fifteen patients, all with LBC samples containing bizarre cells, were identified in routine ThinPrep® LBC workload. HPV testing was performed in each case using residual LBC material. Cytological-histological correlations were reviewed.

RESULTS: All 15 LBC samples contained bizarre cells and tested positive for high-risk HPV types. Ten of the 15 cases were identified as atypical squamous cells - cannot exclude an HSIL (ASC-H) with secondary diagnosis of low-grade squamous intraepithelial lesion (LSIL), while five cases were identified as high-grade squamous intraepithelial lesion (HSIL), and a subsequent biopsy was recommended. Additionally, 13/15 cases underwent cone biopsy or hysterectomy within 1-11 months, of which 10 showed histologically confirmed HSIL end-points. LSIL was present in three cases. Bizarre cells were identified in the HSIL epithelium of five cone biopsies.

CONCLUSIONS: Identification of bizarre cells in LBC is straightforward and may facilitate diagnosis. The cytology of bizarre cells is associated with HSIL in cone biopsies. We recommend assigning LBC samples containing bizarre cells as ASC-H with secondary diagnosis of LSIL.