Tracing human papillomavirus in skin and mucosal squamous cell carcinoma: a histopathological retrospective survey

Objective: The annual incidence of squamous cell carcinoma (SCC) has been increasing worldwide. The causative role of human papillomavirus (HPV) in SCC development of cutaneous has been controversial in the literature. In this study, we aimed to assess the presence of the histopathological features of HPV in SCC samples. Materials and Methods: This retrospective study was conducted at a tertiary referral skin center in 2020. Specimens of patients with a definite SCC diagnosis were evaluated for histopathological features of HPV, including koilocytosis, hyperkeratosis, acanthosis, hypergranulosis, parakeratosis, solar elastosis, papillomatosis, as well as the grade of the tumor. All the samples were re-evaluated by two dermatopathologists independently. Results: a total of 331 (male:female ratio= 3.9:1) cases of SCC were analyzed. The mean age was 68.1, with a 15.1 standard deviation. Most lesions were located on the face (40.5%), followed by the scalp (22.7%) and extremities (20.8%). Koilocytes were detected in 50 (15.1%) of lesions. The koilocytosis proportion was significantly higher in lesions on nails (38.1%, P-value= 0.007), oral cavity (36.8%, P-value= 0.014), and genitalia lesions (60.0%, P-value= 0.026). Although SCCs in-situ were found in 6.6% of our specimens, the highest koilocytosis proportion (64.7%) was detected in in-situ tumors, which was significantly more than other grades (P-value< 0.001). Conclusions: The histopathological features of HPV and in specific koilocytes can be frequently seen in SCC pathology. This association is more prominent in nail, oral, and genital lesions and is significantly higher in well-differentiated SCC.