[Pneumatosis cystoides intestinalis, a rare complication of mixed connective tissue disease]

A 77-year-old woman presented with diarrhoea and increasing malaise. The patient reported a weight loss of 30 kilogram over the past 12 months due to recurrent episodes of diarrhoea. During previous hospitalisations the diagnosis of a mixed connective tissue disease had been established, and the patient was treated with azathioprine and prednisolone. Clinical findings at presentation included diffuse oedema of the hands, Raynaud's and Sicca syndrome, dysphagia and a distended abdomen and pain on palpation of the left lower abdomen.

A chest X-ray revealed pneumoperitoneum. Contrast medium radiography of gastro-intestinal passage and an abdominal CT with contrast medium confirmed the existence of pneumoperitoneum and showed, in addition, intramural gas in the wall of the dilated jejunum. No contrast medium leakage as an indicator of an open perforation was detectable.

Due to suspected encapsulated perforation a laparotomy was performed. In situ, multiple gas bubbles were found both in the bowel walls and in the mesentery. The small intestine was severely distended, atonic but without evidence for a stenosis. In the absence of an open perforation, the diagnosis of pneumatosis cystoides intestinalis (PCI) was established as the underlying cause of the pneumoperitoneum. Treatment with metronidazole was initiated and the diarrhoea resolved over the following 3 weeks.

PCI is a rare condition, to be considered if pneumoperitoneum is present. One possible underlying cause is an intestinal manifestation of a mixed connective tissue disease.