Journal List > J Korean Soc Radiol > v.65(5) > 1087039

Lee and Kim: Pericoccygeal Epidermoid Cyst: Report of Two Cases


Pericoccygeal epidermoid cyst is a rare benign congenital lesion lined with keratinized squamous epithelium. We report the magnetic resonance imaging findings of an epidermoid cyst at the precoccygeal tip as a cause of coccygodynia in a 32-year-old woman and a retrococcygeal epidermoid cyst in a 27-year-old man. We also describe the pericoccygeal lesions and coccygodynia.

Figures and Tables

Fig. 1

A 32-year-old woman with a precoccygeal epidermoid cyst.

A. Coccyx plain lateral view shows bony erosion (arrows) at the coccygeal tip.
B, C. Enhanced CT scan (B) reveals a well defined nonenhanced mass with thin wall, anterior to the coccyx (arrows). Bone setting CT scan (C) demonstrates bony erosion at the coccyx (arrows).
D. Sagittal T2 weighted magnetic resonance image shows a well defined, heterogeneous hypointense signal mass (arrow) with a low signal rim between rectum and coccygeal tip.
E. On postcontrast fat suppressed T1-weighted sagittal image, this mass shows no remarkable enhancement (arrow).
F. Photomicrograph shows some keratinous materials lined by stratified squamous epithelium with a well-formed granular layer (H&E, × 100).
Fig. 2

Magnetic resonance imaging in a 27-year-old man with a retrococcygeal epidermoid cyst.

A. Sagittal T1-weighted image (WI) shows a well defined soft tissue mass (arrow) with a slightly increased signal intensity to surrounding muscle in the retrococcygeal region.
B. This mass (arrow) is located in the subcutaneous region of the intergluteal fold and shows a heterogeneous intermediate to high signal intensity with a high signal rim on coronal T2WI.
C. Postcontrast fat suppressed T1-weighted axial image demonstrates no remarkable enhancement (arrow) of this mass, suggesting cystic lesion.


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