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A Case of a Giant Trichilemmal Cyst on the Forehead
Nariaki Takamura1, Kenichi Amo1, Yu Yusa2
1Department of Plastic and Reconstructive Surgery, Japanese Red Cross Ishinomaki Hospital, Miyagi, Japan.
Abstract:
Trichilemmal cysts are the most common benign subcutaneous cysts on the scalp. Approximately 90% of trichilemmal cysts appear on the scalp and have trichilemmal keratinization without a granular layer visible on pathological examination. In addition, proliferating trichilemmal tumors, which occur in 2% of trichilemmal cysts, show local recurrence and ulceration, making them highly locally aggressive and requiring careful differentiation. We report the case of a 56-year-old man with a giant trichilemmal cyst on his forehead. After computed tomography and magnetic resonance imaging, a subcutaneous cyst was suspected and excised, and a pathological diagnosis of trichilemmal cyst was established. This was a rare case as the trichilemmal cyst was not located on the scalp, the most common site, but on the forehead area, and it was exceedingly large, with a maximum diameter of 9 cm.
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