Epidermal Inclusion Cyst of the Umbilicus in a Child

Epidermal cyst is a common benign cutaneous tumor that predominantly occurs on the face, trunk, and neck, where hair follicles are present. The umbilicus is one of the rarest sites of epidermal cyst, and only a few umbilical epidermal cysts have been reported, primarily in adults. Herein, we report a rare case of umbilical epidermal cyst in a child, which should be included in the differential diagnosis of umbilical skin lesions. A 7-year-old girl visited us for an asymptomatic protruding nodule on her umbilicus that had gradually increased in size over three years. Physical examination showed a 0.8 cm × 0.8 cm pearly gray, spherical nodule in the umbilicus. Dermoscopy revealed shiny white structures with arborizing vessels on the surface of the nodule. Ultrasonography revealed a well-circumscribed cyst confined to the skin layer, but tubular structures penetrating into the abdominal cavity or connecting to internal organs were not seen. Histopathologic findings of the tissue from complete excision of the mass showed a cyst that is lined with stratified squamous epithelium with granular layer and containing keratins. No complication or recurrence was observed during the 6 months after tumor removal.