Keratoacanthoma associated to cutaneous horn manifestation: case report and difficulty of diagnosis
Background: Cutaneous horn (CH) is a conical hyperkatotic projection of skin with keratotic material. A broad variety of lesions may be found with clinical aspect of cutaneous horn, including malignant tumors. Case report: We report a case of patient with 77- year-old male, presenting an asymptomatic lesion with clinical aspect of CH in lower lip. The clinical diagnosis hypothesis was squamous cell carcinoma (SCC) and an incisional biopsy was performed. The histopathological analysis revealed a keratoacantoma (KA) and the lesion was completely removed. The one year follow-up revealed no recurrence. Discussion: CH rarely is accompanied by KA. However, KA shows a greater degree of nuclear atypia than SCC making the differentiation of two diseases very difficult. This case highligh the importance of histopathological examination to rule out malignancy.