Pneumomediastinum as a presenting symptom of perforated sigmoid cancer: a case report.

We report a rare case of spontaneous pneumomediastinum due to perforation of sigmoid cancer in a patient suffering from Vogt-Koyanagi-Harada syndrome and temporal arteritis, two rare diseases. This patient, who generally receives corticosteroid and methotrexate therapy, was admitted to hospital with vague abdominal and left flank pain, urinary disorders and low grade fever one day prior to admission. Initial evaluation including X-ray and laboratory tests was normal. Several hours later a repeat chest X-ray showed pneumomediastinum. Chest and abdominal Computed Tomgraphy were performed because of worsening abdominal pain, and revealed a perforated sigma due to carcinoma.