Diagnosis and treatment of keratoacanthoma in the lower lip: A case report

Keratoacanthoma diagnosis is challenging, and therefore, this publication contributes to the current literature by presenting epidemiological data and describing clinical and histopathological characteristics and the treatment decision. A 69-year-old Caucasian male patient presented with a well-delimited exophytic growth nodule in the lower lip measuring 10 millimeters with circular shape, firm consistency, pink color, and rough surface. The clinical suspicion was squamous cell carcinoma. An incisional biopsy and histopathological analysis were performed, which revealed fragments of oral mucosa lined by hyperparakeratinized stratified squamous epithelium with a center filled with keratin, corneal pearls, pseudoepitheliomatous hyperplasia, and areas of epithelial dysplasia. The diagnosis of keratoacanthoma was determined. Surgical resection was performed, completely removing the lesion, and histopathological analysis confirmed the diagnosis of keratoacanthoma. The fact that the patient was male, over 45 years old, and Caucasian agrees with the epidemiology of the population most affected by keratoacanthoma. The histopathology of the case corroborates the classic characterization, mainly the central depression filled with keratin. The treatment chosen was surgical resection with a small margin of safety, according to the current literature. Keratoacanthomas are more common in males aged over 45 years and in Caucasian individuals. The main etiology is sun exposure without protective measures. It presents as an exophytic nodule with a firm consistency, rough surface, and center filled with keratin. Histopathology is characterized by a crateriform structure, dyskeratosis, and the presence of corneal pearls. The most indicated treatment is surgical resection.