Paraneoplastic cutaneous manifestations in oral and oropharyngeal squamous cell carcinoma: A systematic review.

Paraneoplastic syndromes are remote tumor-driven phenomena that may precede, accompany, or follow the diagnosis of malignancy. Cutaneous paraneoplastic manifestations are of particular clinical importance, as they may represent visible markers of an occult malignancy. While various paraneoplastic phenomena have been reported in oral and oropharyngeal squamous cell carcinoma (SCC), the spectrum and clinical implications of paraneoplastic dermatosis occurring in the context of this cancer remain incompletely characterized. This systematic review was conducted according to the PRISMA 2020 guidelines and registered with PROSPERO (registration number: CRD420251248091). The PubMed/MEDLINE, Scopus, and Web of Science databases were searched through February 14, 2026. Eligible studies reported paraneoplastic syndromes with cutaneous manifestations occurring in patients with histologically confirmed oral or oropharyngeal SCC. The data were synthesized descriptively due to anticipated heterogeneity. Risk of bias of included studies was assessed via JBI tools. Forty-five studies comprising 46 cases were included. Eighteen distinct paraneoplastic syndromes with cutaneous manifestations have been reported, with Bazex syndrome, followed by dermatomyositis, which is the most frequently reported entity. In most cases, cutaneous manifestations precede cancer diagnosis and frequently demonstrate a parallel clinical course with tumor activity. Although rare, cutaneous paraneoplastic manifestations in oral and oropharyngeal SCC are uncommon but clinically significant. Recognition of characteristic dermatoses could facilitate earlier cancer detection and treatment. The evidence base remains limited to case reports and case series, highlighting the need for standardized diagnostic criteria and prospective multicenter studies. No external funding was received for this study.