Neurofibromatosis and Intrathoracic Meninqocele

Abstract

IN 1933 POHL (1) reported the first case of intrathoracic meningocele which was associated, incidentally, with cutaneous neurofibromatosis. Since that time there have been described 19 similar cases and 10 of meningocele without neurofibromatosis. Of 3 bilateral cases, 2 were associated with neurofibromatosis. The pathologic changes which permit the formation of a meningocele have been the subject of much discussion, and several theories have been advanced. We are presenting in this article an additional case of bilateral intrathoracic meningocele associated with neurofibromatosis, with a sevenyear follow-up. We are also proposing a theory of genesis. A 36-year-old Caucasian female was admitted to the hospital in 1949 for investigation of a mass in her right chest. Recurrent episodes of low thoracic pain had occurred over the past ten years. Slight tenderness was present over the lower thoracic vertebrae but no bone abnormalities could be palpated. Numerous soft skin papules and brownish pigmentations typical of von Recklinghausen's neurofibromatosis were found. No neurologic deficit was noted. Roentgenograms (Fig. 1) revealed a rounded mass in the posterior right chest as well as scalloped defects of the posterior margins of the lower thoracic vertebrae and dislocation of the right eleventh rib (Fig. 2). A preoperative diagnosis of intrathoracic neurofibroma and cutaneous neurofibromatosis W'lS made. Thoracotomy showed the mass to be a large meningocele communicating with the spinal canal through defects in the pedicles of the tenth and eleventh thoracic vertebrae (Fig. 3). The sac was aspirated and excised, and the dura was imbricated over the defect. The postoperative course was uneventful. An overexposed chest film following operation revealed a hitherto unsuspected mass in the left retrocardiac area, but no further treatment was instituted. In the ensuing years the patient was well except for a mild backache. In 1956 this became severe enough to warrant further treatment. Spine films again showed defects in the lower thoracic vertebrae, and myelography revealed a communication between the spinal cord and the left retrocardiac mass (Fig. 4), thus establishing its identitv as a meningocele. This mass had not enlarged in the intervening years and no recurrence was noted on the right. Fusion of the involved vertebral segments was performed and the meningocele was left undisturbed. A review of the 20 published cases of intrathoracic meningocele associated with cutaneous neurofibromatosis revealed vertebral deformities but no other bone involvement. Pohl believed that the changes were caused by periosteal neurofibromas, but Gould (2), reporting on microscopic sections of vertebrae of patients with neurofibromatosis, stated that the only abnormal finding was a very marked excess of osteoid tissue, with relatively little normal bone.