Pneumatosis cystoides intestinalis complicating paraneoplastic dermatomyositis

Pneumatosis cystoides intestinalis (PCI) is a rare condition characterized by the presence of gas-filled cysts within the wall of the digestive tract. Classically, it occurs in lung or colon diseases but rarely in patients with collagen disorders. We report a new case of PCI occurring during the course of paraneoplastic dermatomyositis. A 53-year-old woman was diagnosed with dermatomyositis two years ago. Relapse of dermatomyositis preceded the discovery of metastases for which chemotherapy was initiated with 5-fluorouracil and vinorelbine. Three months later, she was admitted to our department for abdominal pains. On physical examination, the abdomen was distended with normal peristalsis. There was no evidence in favour of active dermatomyositis. Abdominal computed tomography scan showed gas collection in the mesentery, revealing the PCI. There was also pneumoperitoneum. The patient slowly improved with symptomatic treatment. PCI is uncommon in systemic diseases and extremely rare in dermatomyositis. The pathogenesis and aetiology of PCI are unknown in most cases. In collagen diseases, several hypotheses have been suggested: digestive hypokinesia, corticosteroid-induced ulceration and intestinal vasculitis. In our patient, two factors contributed to PCI: corticosteroid administration and a chemotherapeutic agent (vinorelbine), resulting in severe constipation. Diagnosis of PCI is based on abdominal computed tomography. Pneumoperitonitis is frequent. Although rare, the diagnosis of PCI must be evoked in collagen disorder patients presenting nonspecific abdominal symptoms.