A Low-Risk HPV-Associated Well-Differentiated Squamous Cell Carcinoma of the Cervix with Low-Grade Squamous Intraepithelial Lesion Morphology: Clinical and Pathologic Diagnostic Difficulties and Review of the Literature.

Approximately 95% of cervical squamous cell carcinomas are associated with high-risk HPV, with a small number of HPV-independent tumors. However, low-risk HPV types have also been detected in rare cervical squamous cell carcinomas. Low-grade squamous intraepithelial lesion-related changes are a rare morphologic finding in cervical squamous cell carcinoma. We present the case of a 30-yr-old woman who presented with pelvic pain and foul-smelling vaginal discharge showing an exophytic lesion protruding from the cervix. Repeated superficial biopsies showed a low-grade squamous intraepithelial lesion (LSIL) characterized by binucleation and koilocytosis. Chromogenic in-situ hybridization revealed the presence of HPV6/11. The absence of high-risk HPV was confirmed by PCR. After following the patient for nine months without intervention, type III hysterectomy and bilateral pelvic paraaortic lymphadenectomy were performed. Microscopic examination showed well-differentiated squamous cell carcinoma with solid epithelial islands and extensive eosinophilic cytoplasm without pleomorphism. HPV 6 and 11 were also detected with chromogenic in-situ hybridization. Neoplasm invaded the full-thickness of the cervical wall and infiltrated the vagina, parametrium, the proximal ureter and bladder. The patient who received chemoradiotherapy is disease-free at 36 months follow-up. Low-risk HPV-related well-differentiated invasive squamous lesions exist, and such lesions could be a diagnostic pitfall for gynecologists and pathologists; in these cases, radiologic-pathologic correlation and radiologic guided biopsy are mandatory.