case_images: PMC6968711_01
case_images: Preoperative physical examination. The swelling was elastic and hard. There was no scar and no central punctum.
case_images: ICRP_A_1564314_F0001_C.jpg
case_images: PMC6968711_01_ICRP_A_1564314_F0001_C.jpg
case_images: F0001
case_images: Preoperative MRI findings. (a) MRI (T1-weighed image): the mass was slightly hyperintense compared to the muscle and pushing outward against the extensor tendons (arrows). (b) MRI (T2-weighed image): the mass was slightly hyperintense compared to the muscle (arrows).
case_images: ICRP_A_1564314_F0002_C.jpg
case_images: PMC6968711_01_ICRP_A_1564314_F0002_C.jpg
case_images: F0002
case_images: It showed a slightly high intensity on both T1-weighted and T2-weighed images and was pushing out the extensor tendons (Figure 2).
case_images: Intraoperative photograph (arrow: antebrachial interosseous membrane). The cystic mass was covered by a thick white capsule and its bottom was adjacent to the antebrachial interosseous membrane. There was no scarring around the fascia.
case_images: ICRP_A_1564314_F0003_C.jpg
case_images: PMC6968711_01_ICRP_A_1564314_F0003_C.jpg
case_images: F0003
case_images: It was covered with a thick white capsule and its bottom was adjacent to the antebrachial interosseous membrane (Figure 3).
case_images: Histopathological findings (hematoxylin-eosin staining, original magnification x 100) upper arrow: squamous epithelium lining, lower arrow: keratin collections. The cyst wall was composed of stratified squamous epithelium with abundant keratin. There were no hair tissue structures or atypical cells.
case_images: ICRP_A_1564314_F0004_C.jpg
case_images: PMC6968711_01_ICRP_A_1564314_F0004_C.jpg
case_images: F0004
case_images: The definite diagnosis was epidermoid cyst without malignancy (Figure 4).