BACKGROUND
Abdominal cocoon syndrome (ACS) is a rare benign peritoneal fibrotic disorder defined by partial or complete small-bowel encasement within dense fibrocollagenous membranes, often causing recurrent episodes of small-bowel obstruction. Nonspecific clinical manifestations and the absence of specific serological or imaging biomarkers frequently lead to clinical misdiagnosis, delayed preoperative recognition, and suboptimal early intervention. The concurrent presentation of idiopathic ACS, acute appendicitis, and mechanical small-bowel obstruction is extremely rare. This atypical triple pathology significantly complicates clinical assessment and hinders timely definitive diagnosis in routine practice.
CASE REPORT
A 55-year-old woman presented with 20 years of unexplained intermittent abdominal pain, with acute symptomatic worsening over 3 days associated with marked abdominal distension, nausea, and vomiting. Multiple previous conservative therapies failed to establish a clear etiology or achieve sustained symptom relief. Emergency abdominal computed tomography (CT) confirmed mechanical small-bowel obstruction and appendiceal fecaliths. Standard in-hospital conservative treatment yielded no obvious clinical improvement. Emergency laparoscopy confirmed diffuse peritoneal fibrosis, complete small-bowel fibrous encapsulation, and concomitant acute appendicitis. Laparoscopic partial fibrous membrane release combined with appendectomy was successfully performed. The patient achieved rapid recovery of gastrointestinal function, with no recurrent abdominal pain or intestinal obstruction during 6-month clinical follow-up.
CONCLUSIONS
ACS should be highly suspected in patients with over 10 years of idiopathic recurrent abdominal pain and no prior abdominal surgery or trauma. Contrast-enhanced abdominal CT serves as a reliable noninvasive screening tool. This rare triple-lesion combination progresses rapidly and requires prompt surgical intervention. Emergency laparoscopy allows simultaneous definitive diagnosis and targeted therapy, and meticulous fibrous membrane release helps reduce disease recurrence and optimize long-term patient prognosis.

Keywords: Case Reports; Missed Diagnosis