A 32-year-old woman presented with a gluteal tumor of 15-day progression and no fever or signs of infection. Physical exploration revealed an immovable ligneous induration with no cutaneous changes. A computed tomography scan (Fig. 1) identified a well delineated collection, measuring 89 × 132 × 140 mm, in the left ischiorectal region, with no clear origin. Given the deep location and significant size of the lesion, complete surgical excision was performed, obtaining a sebaceous cyst that weighed approximately 1 kg (Fig. 2).

Figure 1.

CAT scan. Gluteal tumor of 15-day progression.

Figure 2.

Sebaceous cyst weighing approximately 1 kg.

Culture identified Staphylococcus aureus, Escherichia coli, Actinomyces spp., and anaerobes. Meropenem was administered due to a history of previous infections. Postoperative progression was favorable, and the patient was released on postoperative day two.

Epidermoid cysts in the perianal and ischiorectal region are extremely rare, especially when they are large. Their diagnosis can be complex because they may be confused with abscesses, pilonidal cysts, or soft tissue tumors. Computed tomography and magnetic resonance imaging are essential for evaluating their extension and for surgical planning.1

According to the literature, these cysts are benign, slow-growing lesions, and are more frequent in the face, neck, and trunk. Their appearance in the perianal region is exceptional.2 The treatment of choice is complete surgical excision, preventing recurrences.3 Epidermoid cysts tend to be asymptomatic, but their growth can produce symptoms of compression or inflammation, making their early identification essential for adequate management.