Pararectal Epidermal Inclusion Cyst in a Pediatric Patient

Abstract

Epidermal inclusion cysts, commonly found cutaneously, rarely manifest in the pelvis. They are typically asymptomatic and often occur following trauma or surgical interventions. Imaging modalities, notably computed tomography (CT) scans and magnetic resonance imaging (MRI), play a crucial diagnostic role. Herein, we report a rare case of a four-year-old female with a complicated medical and surgical history, presented with pain in the right gluteal region in the setting of past history of abscess drainage in the same area. Imaging revealed a cystic lesion in the right pararectal space and a fistula extending between the pelvic cavity and gluteal region. A laparotomy was performed, and a histopathologic examination confirmed the diagnosis of an epidermal inclusion cyst with no evidence of malignancy.

Keywords: epidermal inclusion cyst; epidermoid cyst; fistula; gluteal area; gluteal region; pararectal space; pelvic cavity.

Figure 1. Magnetic resonance imaging (MRI): (A) Axial cross-section shows a large enhancing right gluteal collection with a deep fistula, the tract is about 6.1 cm long, indicating the described cystic lesion and both hips were normal; (B) the coronal cross-section shows the elongated cyst.

Figure 2. Computed tomography (CT).

(A) Coronal view reveals a non-enhancing, well-defined cyst in the right pelvic cavity, measuring approximately 7 cm long and 4 cm wide. Additionally, a beaver tail liver was noted, along with mild scoliosis. No other significant issues were observed. (B) In the sagittal view, the depth of the cyst is measured as 3.6 cm, with the upper part located presacrally and the lower part posterior to the urinary bladder in the right pararectal space. No calcifications, septations, or soft tissue are present inside the cyst, and there is no wall enhancement.

Figure 3. The excised cyst measuring 7 cm x 3.5 cm x 4 cm was removed carefully as one block; the wider part was presacral and the rest was pararectal.