Cutaneous Horn with Underlying Squamous Cell Carcinoma of Lower Lip

Context: Cornu cutaneum associated with squamous cell carcinoma is a relatively unusual presentation in lower lip. Cutaneous horn may be associated with benign, premalignant, or malignant cutaneous lesions and is characterized by the presence of abnormal keratinized material. Here we present a 63-year-old female patient with a cutaneous horn in lower lip with underlying squamous cell carcinoma of left buccal mucosa. Aims: This case report aims to draw attention to the fact that cutaneous horn can occur very rarely in association with malignancy. Materials and methods: Tissue was fixed in 10% formalin; 0.3 μm thick sections were obtained from paraffin-embedded tissues, stained with routine hematoxylin and eosin stains, and then reviewed. Conclusion: Examination of hematoxylin and eosin stained sections showed fibrocollagenous tissue lined by hyperkeratinized, dysplastic stratified squamous epithelium, with subepithelial foci of dysplastic squamous cells, suggestive of carcinoma in situ with suspicion of early invasive squamous cell carcinoma.