Basaloid Squamous Cell Carcinoma of the Uterine Cervix: An Often Aggressive Subtype Frequently Underestimated by Cytology

Basaloid squamous cell carcinoma of the cervix (BSCC) is an extremely rare subtype. In the 2020 WHO classification, BSCC is considered a subtype within HPV-associated squamous cell carcinoma. We report a case wherein liquid-based cytology (LBC) initially suggested a high-grade squamous intraepithelial lesion (HSIL). Retrospective review, prompted by the histologic diagnosis of BSCC, revealed diffuse sheets of monotonous basaloid and parabasaloid cells. Key cytologic features included three-dimensional clusters with occasional papillary architecture, palisading, and cord-like arrangements-findings that can be misleading. This case underscored that BSCC's deceptively bland cytology often overlaps with HSIL, contributing to diagnostic under-call. Increased awareness of these subtle yet distinctive patterns is crucial for accurate identification and appropriate clinical management of this rare variant.