Uncommon Manifestation of Tuberculosis: Sclerosing Encapsulating Peritonitis in an Adolescent Girl

To the Editors: A 12-year-old girl presented with nonbilious nonprojectile vomiting and constipation for 1 week, preceded by low-grade fever, dull-aching diffuse abdominal pain for 6 weeks. She experienced loss of appetite and significant weight loss (4 kg in 6 weeks; 12% cumulative). There was no difficulty in passage of flatus, dysphagia, jaundice, chronic cough or neurological symptoms. She had no prior abdominal symptoms or surgeries and had regular menstrual cycles. Her mother had been treated for spinal tuberculosis (TB) 1 year prior. Examination revealed an afebrile child with stable vitals who was thin, underweight (weight- 29 kg; 3rd centile, body mass index 14 kg/m2; −2 to −3Z) and pale, with no icterus, clubbing, lymphadenopathy or edema. Abdomen was doughy on palpation with diffuse tenderness (in the right lower quadrant) and sluggish bowel sounds, without guarding, rigidity, hepatosplenomegaly or free fluid. Investigations showed moderate anemia (hemoglobin: 9.2 g/dL), elevated erythrocyte sedimentation rate (62 mm/h) and positive tuberculin sensitivity test (15 mm induration). HIV serology was negative. Abdominal ultrasonogram showed septated ascites with thick echogenic omentum in the right iliac fossa, while X-ray showed no air-fluid levels. A provisional diagnosis of abdominal TB was kept, and she was started on the intensive phase of 4-drug antitubercular therapy (ATT). GeneXpert and microscopy for acid-fast bacilli of gastric aspirate were negative. Contrast-enhanced computed tomography of the abdomen (Fig. 1) showed right-sided loculated ascites, enhancing thickened peritoneum, mesenteric adenopathy, omental caking and clustered small bowel loops encased in a fibrous sac—suggestive of sclerosing encapsulating peritonitis (SEP) or abdominal cocoon. Surgical opinion was obtained for this diagnosis, but the subacute obstruction improved with 1 week of ATT, and she had improved appetite, with passage of stools and flatus.FIGURE 1.: Computed tomography (CT) images of the child showing. A: Conglomerated bowel loops encased within the thickened peritoneum (yellow arrow) with interbowel ascites. B: Lateral view of conglomerated bowel loops encased within the thickened peritoneum forming a cocoon (red arrow). C: Prominent encased conglomerated bowel loops (blue arrow) – subacute intestinal obstruction due to sclerosing peritonitis.Our case highlights the diagnostic challenge of tubercular SEP in an adolescent who presented with features of subacute intestinal obstruction. The diagnosis of abdominal TB is challenging in children who present with nonspecific symptoms of fever, chronic ill health, altered bowel habits and abdominal pain.1 Peritoneal TB presents typically as a wet form with ascites, or as a fibrotic palpable mass in the right iliac fossa. Less common is the dry-plastic form with tubercles, adhesions and fibrotic peritonitis, which may be complicated by bowel loop encasement as a fibrosed cocoon -called SEP- demonstrated better by imaging.2 While SEP has been described following chronic peritoneal dialysis and abdominal surgery, TB as an etiology is rare.3,4 Intraoperative findings of small bowel encasement and dense interbowel adhesions with enlarged caseating mesenteric nodes and serosal tubercles support this etiological diagnosis, which is confirmed by histopathology, while microbiological demonstration of acid-fast bacilli is rarely possible.3–5 Table, Supplemental Digital Content 1, https://links.lww.com/INF/G447 shows an overview of reported pediatric cases of tubercular SEP. Conservative management with ATT was opted for our patient without acute intestinal obstruction based on this clinico-radiologic picture. We aim to emphasize the need for clinical suspicion of such an atypical manifestation of abdominal TB, considering chronic abdominal symptoms. With supportive imaging, SEP should be a differential diagnosis in subacute cases, allowing for successful conservative management.