A 52-year-old woman presented for evaluation of a painless mass in the left intergluteal cleft region. It had been present for 10 years but had enlarged significantly over the previous year. When the patient first noticed it a decade previously, the lesion had been the size of a peanut. The patient had no other relevant medical or trauma history. Physical examination revealed a 6-cm, partly compressible, superficial mass with no tenderness or associated skin changes. There was no visible fistulous opening or discharge from the lesion. Laboratory results—including complete blood count, biochemical blood tests, and tumor markers—were within their normal ranges. Ultrasonography showed a well-circumscribed hypoechoic lesion with posterior enhancement and internal echogenic foci. Color Doppler images showed no signal on the mass. Subsequently, computed tomography (CT) showed a 6.8 × 6.3 × 5.1 cm, lageniform, homogeneous, soft tissue-attenuation lesion (41–52 HU) in the subcutaneous fatty tissue of the intergluteal cleft region. The lesion showed no internal calcification or post-contrast enhancement. Magnetic resonance imaging (MRI), performed to further characterize the mass, revealed a bilocular cystic lesion without contrast enhancement or solid components. The mass showed heterogeneous signal intensity comprising slight to marked hyperintensity on both T1- and T2-weighted images —in contrast to adjacent muscle, which showed no contrast, solid components, or restricted diffusion foci. Based on these findings, the most likely diagnosis was a subcutaneous epidermoid cyst. Hence, the mass was surgically excised without postoperative complications. Macroscopically, it was a well-defined, gray-tan cystic mass that contained brownish mucous material. Histopathological examination of the resected cyst showed that it was lined with pseudostratified ciliated columnar epithelium, which was consistent with it being a BC. Hemorrhage, inflammatory cells, and fibrosis were present but no signs of malignancy. The patient’s postoperative course was uneventful, and she was discharged from the hospital on postoperative day 4. Clinical follow-up and CT at 11 months showed no signs of recurrence.