[Colonic lumbar hernia secondary to congenital bone anomalies in a case of neurofibromatosis type I].

We report here a case of an asymptomatic lumbar hernia through a congenital defect of the posterior abdominal wall secondary to hypoplasia of the left part of the neural arch of L5 and S1. The bone defect was related to the neurofibromatosis of the patient. Plain radiograms showed a scoliosis and the bone defect. CT scan confirmed the osseous abnormalities and demonstrated a left colonic herniation through the bone defect. Many cases of lumbar hernia secondary to weakness of the abdominal muscles or following bone defects after bone graft harvesting, surgery or trauma have been described. This is, to our knowledge, the first case report of a lumbar hernia secondary to a congenital bone defect.