Pneumatosis intestinalis after molecular targeted therapy.

BACKGROUND: Pneumoperitoneum after surgical manipulation of the abdomen implies a perforation. Rare cases of non-operated cancer patients, largely with gastrointestinal or genitourinary cancers, have been noted to have radiological findings of pneumatosis intestinalis and/or pneumoperitoneum as a complication of molecular-targeted therapy (MTT) without confounding factors for perforation. We present a patient with a cranial malignancy treated with bevacizumab who subsequently manifested with pneumatosis intestinalis.

CASE: A 67 year-old man with metastatic melanoma, non-small cell lung cancer, and recurrent cerebellar subependymoma was initiated on bevacizumab treatment for subependymoma recurrence. He subsequently underwent an uncomplicated ventriculoperitoneal shunt (VPS) for progressive obstructive hydrocephalus, confirmed by a normal post-operative abdominal x-ray. One week later, he returned with worsening lethargy and a CT consistent with pneumomediastinum and pneumoperitoneum. Due to concern for bowel perforation, the patient underwent diagnostic laparoscopy and removal of VPS. Focal sigmoid pneumatosis was identified without any signs of bowel perforation or ischemia. Bevacizumab was discontinued and the patient's radiological and clinical findings improved.

CONCLUSION: With increasing utilization of molecular-targeted therapies in brain tumor management, we raise MTT as a potential cause for pneumoperitoneum in neurosurgical patients. Pneumoperitoneum after extracranial procedures still requires workup and management for potential bowel perforation, but alternative causes such as bevacizumab should also be considered. Pneumatosis intestinalis patients on MTT can have benign physical exams and will resolve, in the majority of cases, upon discontinuation of the drug.