ABSTRACT
ABSTRACT: Enteric duplication cysts (EDCs) are rare congenital malformations consisting of double-walled cystic or tubular structures lined by gastrointestinal type epithelium. EDCs share a common muscular wall and blood supply with the adjacent duplicated bowel with very rare exceptions. The majority of EDCs are intraabdominal with cases less commonly intrathoracic or thoracoabdominal. To the best of our knowledge, we present the first reported case of primary cutaneous EDC to occur outside the abdominal and thoracic cavities. A 17-year-old male without a significant medical or surgical history underwent excision of a cystic nodule on the left hip. On histopathology, a dermal to subcuticular cyst exhibited an epithelial lining with 2 distinct components including cuboidal to columnar mucinous cells (CK7+, CK20-, and CDX2-) and complex glandular colonic-type mucosa (CK7-, CK20+, and CDX2+). A thick muscular wall resembling muscularis mucosa and muscularis propria surrounded the cyst. Findings supported a primary cutaneous enteric duplication cyst of uncertain developmental etiology. The novel nature of this entity could represent a diagnostic challenge.