06 November 2025
: Case report 
A Rare Diagnosis of HPV-Positive Rectal Squamous Cell Carcinoma in a 59-Year-Old Heterosexual Woman: Implications for Screening Guidelines
Rare disease, Educational Purpose (only if useful for a systematic review or synthesis), Rare coexistence of disease or pathology
Adebola O. Adetiloye
BDEF 1*, Anim Asif BEF 1, Olurotimi J. Badero EF 2, Zimri Tan E 1, Earl Scott E 1
DOI: 10.12659/AJCR.950554
Am J Case Rep 2025; 26:e950554
Figure 3 Immunohistochemical analysis of the solid tumor. Positive results were documented for broad-spectrum cytokeratin (AE1/AE3) and squamous markers (cytokeratin [CK]5/6, p63), confirming the epithelial and squamous nature of the lesion. Strong cyclin-dependent kinase inhibitor 2A (p16-INK4a) positivity served as a surrogate marker of transcriptionally active HPV infection. In situ hybridization confirmed the presence of high-risk human papillomavirus types 16, 18, and 33, supporting viral-driven pathogenesis.