S3827 Pneumatosis Cystoides Intestinalis in the Setting of a Bronchoperitoneal Fistula: A Rare Clinical Entity

Introduction: Pneumatosis cystoides intestinalis (PCI) is a rare condition characterized by the presence of gas-filled cysts within the wall of the gastrointestinal tract. Clinical manifestations range from asymptomatic to symptoms such as abdominal pain, distention, or diarrhea. PCI may be idiopathic or secondary to a variety of conditions, including gastrointestinal disorders or prior abdominal surgeries. We report an exceedingly rare case of a 76-year-old woman with a history of hiatal hernia repair who was incidentally found to have air-filled cystic structures within the bowel wall, consistent with PCI, secondary to a rare bronchoperitoneal fistula. Case Description/Methods: A 76-year-old woman with a past medical history of hypertension, type 2 diabetes mellitus, HFrEF, sick sinus syndrome status post pacemaker, and hiatal hernia status post repair 5 years ago presented with new-onset hematuria. Three months earlier, she had been hospitalized for an abnormal cardiac rhythm and underwent pacemaker implantation. At that time, she was incidentally found to have a pneumoperitoneum without any associated symptoms. She subsequently underwent a diagnostic laparotomy and endoscopy which did not reveal any evidence of bowel perforation. The patient also reported a 1 year history of intermittent fecal incontinence, characterized by loose, watery, brown bowel movements with excessive flatulence. On admission, the patient was alert and oriented to person, place, and time, and appeared in no acute distress. Vital signs were stable. Physical examination revealed a soft non-tender abdomen mildly distended without rigidity or guarding. Laboratory results with a creatinine level of 1.19 mg/dL from a normal baseline. A computed tomography scan obtained to evaluate hematuria revealed worsening pneumoperitoneum with PCI with multiple air-filled cystic structures within the submucosal layer of the bowel wall. A prior operative report noted a halothane-like odor during the laparotomy, raising suspicion for a fistula, which was confirmed in a ventilation-perfusion scan as a bronchoperitoneal fistula. Discussion: PCI is an uncommon condition that poses a diagnostic challenge due to its variable clinical presentations. While PCI is generally benign and uncomplicated, the identification of a fistula shifts the differential toward a secondary and complicated process. This case highlights a rare and diagnostically challenging scenario that can significantly impact a patient’s quality of life and in some cases can lead to severe complications.