Comprehensive Clinicopathological and Immunohistochemical Analysis of Human Papillomavirus-independent Squamous Cell Carcinoma and Adenosquamous Carcinoma of the Uterine Cervix

Background/Aim: Human papillomavirus-independent (HPVI) squamous cell carcinoma (SCC) and adenosquamous carcinoma (ASC) of the uterine cervix are extremely rare. The aim of this study was to comprehensively describe the clinicopathological features, patient outcomes, and immuno-phenotypes of HPVI SCC and ASC. Patients and Methods: We found four and two patients with HPVI SCC and ASC, respectively, and reviewed their electronic medical records and pathology slides. We also performed immunostaining for p16 and p53. Results: All except one patient underwent surgery. Two, one, and one patients with HPVI SCC were diagnosed as having IIIC1, IVA, and IVB diseases, respectively. Two patients with HPVI SCC experienced recurrences, and died of disease within nine months after treatment initiation. Both patients with HPVI ASC developed lung metastasis at four months post-operatively. HPVI SCCs and the squamous component of HPVI ASCs showed keratinizing, condylomatous, or poorly differentiated morphology. The glandular component of HPVI ASCs was gastric-type endocervical adenocarcinoma. None of the six tumors exhibited block positivity for p16. Two HPVI SCCs and one HPVI ASC displayed aberrant p53 expression. Conclusion: HPVI SCC is a rare and aggressive cervical malignancy that presents initially as advanced-stage disease with poor prognosis. Although the patients with initial stage I and II HPVI ASC were treated with curative intent, distant metastases appeared in the lungs during the early course of treatment. Further investigations are necessary to clarify the association between histological features and clinical behavior of HPVI ASC.