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Case Reports
. 2023 Jul 31;3(1):21-25.
doi: 10.53045/jprs.2022-0044. eCollection 2024 Jan 27.

A Case of a Giant Trichilemmal Cyst on the Forehead

Nariaki Takamura  1 , Kenichi Amo  1 , Yu Yusa  2 , Yusuke Takezawa  1
Affiliations
Case Reports

A Case of a Giant Trichilemmal Cyst on the Forehead

Nariaki Takamura et al. J Plast Reconstr Surg. .

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.

Keywords: epidermal cyst; proliferating trichilemmal cyst; trichilemmal cyst.

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Conflict of interest statement

Conflicts of Interest: There are no conflicts of interest.

Figures

Figure 1.
Figure 1.
Tumor photograph. A spherical tumor 9 cm in diameter in the left anterior forehead area hanging over the visual field.
Figure 2.
Figure 2.
CT image of the tumor. (a) A calcified lesion is visible in the tumor. (b) The skull area directly below the tumor is intact.
Figure 3.
Figure 3.
MRI images of the tumor. (a) T1-weighted image shows an equal to slightly higher signal inside the tumor compared to the gray matter. (b) T2-weighted image shows a high signal inside the tumor. (c) Contrast-enhanced T1-weighted image shows no contrast effect inside the tumor.
Figure 4.
Figure 4.
Photographs of the surgery. (a) The skin incision is designed to ensure suturing. (b) The supraorbital nerve is shown, compressed by the tumor. (c) Skin after suturing.
Figure 5.
Figure 5.
Photograph of the resected tumor. Its diameter is 9 cm, and the entire capsule is removed.
Figure 6.
Figure 6.
Micrographs. (a) Keratinization is seen without a granular layer (trichilemmal keratinization). (b) Papillary structure. No cell proliferation can be observed.
Figure 7.
Figure 7.
Photograph taken 2 years after surgery. The sutures are progressing well, and there is no recurrence.
See this image and copyright information in PMC

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