The central nervous system pathology in multiple neurofibromatosis

Symptomatic hamartoma of the spinal cord associated with neurofibromatosis type 1. Case report

The authors present a case in which a symptomatic hamartoma was found in the spinal cord of a patient with neurofibromatosis type 1 (NF-1). This 52-year-old woman presented with painful urinary incontinence. Magnetic resonance (MR) imaging revealed an intramedullary lesion within the lower thoracic spinal cord and conus medullaris, which was surgically removed. Pathological investigation showed a hamartomatous lesion consisting of glial cells, ganglion cells, abundant disoriented axons, and thin-walled vessels. This case provides a pathological correlate to the hamartomatous lesions demonstrated on MR imaging in patients with NF-1 and illustrates that these benign lesions may become symptomatic and require neurosurgical intervention.

Cerebral glucose metabolism in neurofibromatosis type 1 assessed with [18F]-2-fluoro-2-deoxy-D-glucose and PET

Cerebral PET with [18F]-2-fluoro-2-deoxy-D-glucose has been performed in four patients with neurofibromatosis type 1 (NF1) to assess the relation between cerebral metabolic activity, MRI, and the presence of neurological symptoms, including seizures, as well as mental and language retardation. Widespread hypometabolism occurred in three of the patients. The lesions on MRI, which were localised in the subcortical white matter and grey structures, had normal rates of glucose metabolism. This finding suggests that the abnormalities seen on MRI are not due to defective blood supply, localised oedema, or grey matter heterotopic foci as previously hypothesised. The presence of the hypometabolic areas seems to be inconsistently related to the occurrence of seizures and is not proportional to the degree of mental impairment. This study provides evidence of a widespread cerebral hypometabolism that is not related to the presence of MRI abnormalities; conversely normal metabolism was present in the areas with an abnormal MRI signal.

Vascular neurofibromatosis affecting the internal carotid artery: a case report

A patient with von Recklinghausen's disease presented with a right sixth nerve palsy. Investigations demonstrated unilateral dolichoectasia of the intracranial carotid artery and sphenoid wing dysplasia. This case demonstrates an association not previously documented, that of unilateral fusiform dilatation of the carotid artery with sphenoid wing dysplasia in the presence of classical neurofibromatosis.

Benign spinal nerve sheath tumors: their occurrence sporadically and in neurofibromatosis types 1 and 2

Benign spinal nerve sheath tumors (neurofibromas and schwannomas) often occur on dorsal nerve roots sporadically or in neurofibromatosis types 1 and 2. These are histologically benign tumors, and distinction between them is frequently not made by clinicians. To determine if there is a correlation between the histological pattern of benign spinal nerve sheath tumors and the type of neurofibromatosis, the clinical and pathological features of these tumors (86 surgical specimens and five autopsies) in 68 patients were reviewed. The patients were classified into one of four categories: neurofibromatosis type 1, neurofibromatosis type 2, uncertain, or sporadic. The diagnostic criteria used for neurofibromatosis types 1 and 2 were established by the National Institutes of Health. Patients who did not fulfill criteria for either neurofibromatosis type 1 or 2 but who had multiple nervous system tumors or other stigmata of neurofibromatosis were designated "uncertain." Spinal nerve sheath tumors were considered sporadic in 42 cases (40 schwannomas and two neurofibromas). In the 14 patients with neurofibromatosis type 1, all spinal nerve sheath tumors were neurofibromas. In six of the seven patients with neurofibromatosis type 2, all spinal nerve sheath tumors were schwannomas. One patient with neurofibromatosis type 2 had a spinal nerve sheath schwannoma and a tumor with features of both tumor types. The authors conclude that spinal nerve sheath tumors in patients with neurofibromatosis type 1 are neurofibromas. In contrast, spinal nerve sheath tumors occurring in neurofibromatosis type 2 or sporadically are most frequently schwannomas. The distinct histological features of these tumors may reflect different pathogenetic mechanisms even though they arise at identical sites in neurofibromatosis types 1 and 2.

Current concepts of neurocutaneous disorders

The neurocutaneous diseases are a loosely bound group of clinical entities that were initially considered to have dysplastic and/or neoplastic changes of the nervous system and skin, though other organ systems are frequently involved. During the last several decades a variety of additional diseases have been included in this disease category despite their not having any known cutaneous abnormality. The major neurocutaneous syndromes are considered in this review.

Neurofibromatosis 2: a clinically and genetically heterogeneous disease? Report on 10 sporadic cases

Clinical and genetic data of 10 patients with neurofibromatosis 2 (NF-2) are presented. Interestingly, no family history of neurofibromatosis was detectable in any of them, which indicates that these are sporadic cases of NF-2, most likely due to a new mutational event. According to our own results and the data in the literature, sporadic cases of NF-2 are clinically characterized by a high incidence of multiple meningiomas and spinal tumors in addition to the bilateral occurrence of acoustic neurinomas. The clinical heterogeneity of NF-2 is pointed out and the possible existence of different forms of this disease is discussed.

Multiple brain tumours with von Recklinghausen's disease

Over the past 10 years we have experienced 33 cases of von Recklinghausen's disease, among whom 5 were cases of multiple (3 or more) brain tumours. In the past we have extirpated multiple tumours in a one-stage operation, but the results were poor. Recently, we have done multi-stage operation in two cases thought to require surgical treatment and have obtained satisfactory results. We have discussed the autopsy results of our own case of multiple neurinomas and meningiomas and have reviewed the 44 reported cases of von Recklinghausen's disease in whom the presence of three or more brain tumours had been confirmed at surgery or autopsy.

Intracranial calcified deposits in neurofibromatosis

Three patients with the central type of neurofibromatosis, who on CT showed multiple subependymal calcified deposits, are presented. The literature on intracranial non-tumourous calcifications in neurofibromatosis is briefly reviewed. On the basis of our findings and the literature, it is proposed that such intracranial calcified deposits may be part of the neurofibromatosis syndrome and are caused by calcium deposits in glial proliferations, analogous to the calcified deposits seen in tuberous sclerosis.

On the pathogenesis of focal nodular hyperplasia of the liver

Fifty-one focal nodular hyperplasia lesions from 36 patients were examined histologically. Serial sections and three-dimensional models were studied in selected cases. Lesions were multiple in 19% of patients. Thirty-four patients were female. One case had 11 focal nodular hyperplasia lesions and 7 hemangiomata in the liver. Three had astrocytoma and one had anomalous pulmonary venous drainage. Morphometric analysis revealed that the lesions were supplied by an anomalous artery larger than expected for the locale in the liver. This artery branched to form a spider-like structure and was usually not accompanied by a portal vein or duct. Each terminal arterial branch supplied a separate nodule 1 mm in diameter; adjacent nodules coalesced to form the focal nodular hyperplasia lesion. The arterial blood appeared to drain directly into the sinusoids of the nodule. We propose that focal nodular hyperplasia is an hyperplastic response of the hepatic parenchyma to a preexisting arterial spider-like malformation. The frequent coexistence of focal nodular hyperplasia with other vascular and neuroendocrine anomalies suggest that the malformations are developmental in origin. The basic requirement for development of hepatic hyperplasia may be greater blood flow to a region compared to the adjacent parenchyma. This requirement appears to be met in the other forms of nodular transformation of the liver, i.e., nodular regenerative hyperplasia and partial nodular transformation.

Solitary intracerebral schwannoma in von Recklinghausen's disease

A case of intracerebral schwannoma of the frontal region in a patient with mixed neurofibromatosis is reported. The possible origins of the tumor are discussed.

A case of sarcoma of the central nervous system presenting as a Guillain-Barré syndrome

A case of widespread spinal sarcoma is described with meningeal infiltration, involvement of the anterior cranial fossa complicated by aplastic anaemia and visceral metastases.

Central neurofibromatosis

Two patients with central form of neurofibromatosis are reported. Bilateral acoustic neuromas were diagnosed by computerized tomography (CT) scan in one and at autopsy in the other patient. The clinical and radiologic features in the first patient indicated associated bilateral optic nerve gliomas. The autopsied case in addition had multiple meningiomas and numerous nontumorous glial hamartomas. The clinical, pathologic and biochemical basis for classification of neurofibromatosis into central and peripheral forms are discussed.

The Sylvian aqueduct syndrome and neurofibromatosis

A 23-year-old man initially presented with the Sylvian aqueduct syndrome and subsequently developed cutaneous neurofibromata. The case is reported and the possibility that these represent manifestations of the same genetic abnormality is discussed.

Neurofibromatosis and intracranial arterial occlusive disease

Two cases of neurofibromatosis and intracranial arterial occlusive disease are reported. The radiographic and clinical features of these and twelve previously reported cases are reivewed.

Familial glioblastoma with hepatic focal nodular hyperplasia

Two siblings succumbed to glioblastoma multiforme, associated with hepatic focal nodular hyperplasia and cafe-au-lait spots. One sibling had syndactyly and multiple colonic polyps, while the other had an angiomatous malformation in the brain. Their mother died of myasthenia gravis. The findings suggest a hamartomatous syndrome of malformations that predisposes to brain tumors.