Trichilemmal carcinoma in an Iranian patient: reporting a rare skin tumor

Trichilemmal carcinoma is a rare tumor of the outer sheath cells of hair follicles. These tumors occur on the sun-exposed skin of the elderly in the majority of cases. The gross tumor demonstrates exophytic, polypoid, ulcerative, or nodular lesions with or without bleeding. Histopathologically, it is characterized by an anastomosing trabecular, diffuse, or lobular growth pattern with clear keratinization. A critical differential diagnosis is squamous cell carcinoma (SCC), where the prognosis of trichilemmal carcinoma is far better than SCC. Surgery is a significant and effective treatment for trichilemmal carcinoma cases, and recurrence after complete surgical resection with a negative margin is uncommon. Trichilemmal carcinoma is considered a low-grade tumor with low metastatic potential. This paper reports a 48-year-old Iranian male with trichilemmal carcinoma of the scalp treated with surgery, having no recurrence after three years of follow-up. The role of other treatment modalities like radiation, local therapy, and systemic therapy are also discussed.