A huge completely isolated duplication cyst complicated by torsion and lined by 3 different mucosal epithelial components in an adult: A case report

RATIONALE: Intestinal or enteric duplication (ED) does exit as a rare congenital malformation of the gastrointestinal system clinically. It is a separate entity, but can be communicated with the gastrointestinal tract. It is characterized by a well-developed muscular wall and lumen endowed with ectopic mucosa, simulating a portion of normal bowel. A completely isolated duplication cyst (CIDC) refers to an extremely uncommon variant of ED, which is secluded from the alimentary tract and possesses its own exclusive blood supply. Surgical procedure is the treatment of choice, because most often, a definitive diagnosis can only be confirmed intraoperatively. PATIENT CONCERNS: A 20-year-old male patient presented with a 10-day history of intermittent episodes of abdominal pain. The pain evolved from dull into progressive and intolerable, accompanied by vomiting, nausea, and abdominal distention. DIAGNOSES: Closed-loop small-bowel obstruction with volvulus. INTERVENTIONS: The patient underwent an emergency exploratory laparotomy. OUTCOMES: A huge CIDC was observed upon operation, which was affixed to the mesentery with only a narrow base, just like a pedicle; 720° counterclockwise twisting around its base was definitely noted, provoking the compromised blood supply. Complete excision of the cyst was performed along its base safely without violating the intestinal tract. Furthermore, the ectopic mucosa of the cyst exhibited 3 different epithelial lining components histopathologically. LESSONS: Clinicians should be aware of the possibility of the existence of a duplication and raise a high index of suspicion in case of equivocal diagnosis, particularly in adult population. A low threshold for surgical management should be recommended in order to prevent lethal outcomes.