A Case of Malignant Proliferating Trichilemmal Tumor Occurring in Lower Lip / 대한이비인후과학회지

ABSTRACT

Proliferating trichilemmal tumor is one of rare benign tumors originating from the outer root of the hair follicle sheath. The tumor is clinically benign, although it can display nuclear atypia, dyskeratotic cells, and mitotic figures. These features can be misleading, and a false diagnosis of a squamous cell carcinoma is possible. An abrupt enlargement of size is suggestive of malignant changes of the tumor. We report a case of a malignant proliferating trichilemmal tumor which occurred not on the scalp but on the lower lip. A 75-year-old man presented a lower lip mass with a smooth surface, measuring 4.5X3 cm, and his right submandibular lymph node was also palpable. The tumor was widely excised with bilateral functional neck dissection, and the defect on the lip was reconstructed using radial forearm free flap including the palmaris longus tendon. No recurrence was observed during the follow-up period.