Multiple schwannomas: schwannomatosis or neurofibromatosis type 2?

OBJECT: The aim of this study was to clarify the clinical outcome of schwannomatosis, a rare condition characterized by multiple nonvestibular schwannomas in the absence of meningiomas, intraspinal ependymomas, and other clinical signs of neurofibromatosis type 2 (NF2). METHODS: Nine patients with schwannomatosis treated at one institution are presented and their clinical course during a median follow-up time of 9.9 years is discussed. The patients were typically middle-aged at the time of their first operation (median 43.5 years), none had a positive family history of schwannomatosis or NF2, and none showed cutaneous or ocular signs of NF2. On histopathological examination the tumors from the patients with schwannomatosis showed a lobular appearance and frequent Verocay bodies, signs indicating NF2, more often than 20 sporadic schwannomas that were investigated as controls. Two patients died of unrelated causes at 3.2 and 9.9 years, respectively, of follow up. Magnetic resonance images of the head and spine were obtained in seven patients at the end of the follow-up period. New spinal schwannomas were detected in one patient and a residual schwannoma in three. No germline mutations of the NF2 gene were found in these seven patients. Two additional patients originally included in the schwannomatosis group who were 8.6 and 11.7 years old at initial surgery had NF2. One was diagnosed at follow-up review and the other developed a fulminant disease that led to death in 4 years. CONCLUSIONS: The clinical course, long-term outcome, and genetic mechanism of schwannomatosis differ from that of NF2.

Long-term outcome after removal of spinal schwannoma: a clinicopathological study of 187 cases.

Are spinal schwannomas as benign as we think? To what extent do patients recover? Are patients prone to develop late complications such as cystic myelopathy or symptomatic spinal deformity? Is their life expectancy compromised? In an effort to answer these questions, the authors analyzed the long-term outcome for 187 patients from one neurosurgical department with surgically treated spinal schwannoma. Median follow-up period was 12.9 years (2454 patient years). One-fifth of the patients considered themselves free of symptoms at follow-up examination. The most common late complaint was local pain (46%), followed by radiating pain (43%), paraparesis (31%), radicular deficit (28%), sensory deficit due to a spinal cord lesion (27%), and difficulty voiding (19%). Late complications occurred in 21% of the patient population, including cystic myelopathy (2%), spinal arachnoiditis (6%), spinal deformity (6%), and troublesome pain (7%). Life expectancy of the patients corresponded to that of the general population.

Long-term outcome after removal of spinal neurofibroma.

Spinal neurofibromas are uncommon, comprising approximately 3% of all spinal tumors. They occur both sporadically and in association with neurofibromatosis 1 (NF1; von Recklinghausen's disease). This study presents the clinical characteristics of 32 patients who underwent surgery for symptomatic spinal neurofibromas. Twenty-two of these patients showed clinical signs of NF1. The patients were typically younger (median age 31 years) than those with spinal schwannomas. The tumors were located mainly in the cervical region and tended to grow both extra- and intradurally. Patients with NF1 were prone to develop new spinal neurofibromas. A life-table analysis showed a reduced survival rate for these patients compared to that of the general population.

Spinal malignant nerve-sheath tumor or cellular schwannoma? A striking difference in prognosis.

Cellular schwannoma, a recently delineated entity, has a histological appearance mimicking that of malignant neoplasms. The aim of this study was to determine the outcome for patients treated for a spinal cellular schwannoma or malignant nerve-sheath tumor. A histological re-examination was conducted of 283 spinal tumors, considered to originate from a nerve root, that were treated in the Department of Neurosurgery between 1953 and 1985. After re-examination, 50 of these were determined to be other tumors or non-neoplastic lesions. The review yielded eight cellular schwannomas and six malignant nerve-sheath tumors out of 233 of nerve-sheath origin. Immunohistochemical staining with a commercially available polyclonal antibody against S-100 protein was positive in all cases of cellular schwannoma, but negative for the malignant tumors. Clinical outcome was favorable for patients with cellular schwannomas, but uniformly poor for those with the malignant tumors.