The human papillomavirus (HPV) has been associated with the carcinogenesis of cutaneous squamous cell carcinoma (cSCC), especially in immunosuppressed patients. This article reviews the microbiology of HPV and its role in tissue tropism, invasion, and oncogenesis. It also describes possible HPV oncogenic ability due to the inactivation of the host p53 and retinoblastoma protein (pRb) by HPV oncoproteins E6 and E7, producing a suppression of cell cycle checkpoints and uncontrolled cell proliferation that may eventually result in invasive carcinoma. We will focus on β-HPV types and their role in epidermodysplasia verruciformis (EV), as well as α types and their ability to cause cutaneous and mucosal pathology. We also intend to examine the clinical characteristics of cSCC related to HPV and host immunosuppression conditions such as solid organ transplant in order to provide management guidelines for patients with cSCC associated with HPV based on available data. Other topics addressed in this article include particular locations of cSCC, such as nails; the prognosis; the recurrence; therapeutic modalities; and the role of HPV vaccines.

Background: Consensus is lacking on adequate deep histological margins in cutaneous squamous cell carcinoma (cSCC). Deep clearance for tumours located on the scalp is limited by anatomic constraints.Objective: To determine whether clear but close deep histological margins (<1 mm) confer a higher risk of recurrence in cSCCs of the scalp treated by wide local excision, compared to deep histological margins ≥1 mm.Methods: Multicentre retrospective observational cohort study and multivariate competing risk analysis to evaluate risk factors for recurrence.Results: In total, 295 patients with 338 cSCCs were included. Close deep histological margins were not associated with an increased cumulative incidence of recurrence (subhazard ratio [SHR] 1.96 [95% CI 0.87–4.41]). However, an increased risk of recurrence was observed for those tumours that presented concurrent invasion of the galea aponeurotica and close deep margins, as opposed to patients without these factors (SHR 3.52 [1.24–10.01]). Tumours with clear but close peripheral margins (<1 mm) also had higher risk of recurrence (SHR 5.01 [1.68–14.97]).Limitations: Retrospective observational study based on pathology reports.Conclusions: Deep histological margins <1 mm do not confer a greater risk of recurrence as long as the tumour is completely excised and the galea aponeurotica is not involved. Surgical excision of cSCC on the scalp should include the galea to ensure proper assessment of deep margins.