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PubMed1991

Early lesion of N-nitroso-N-ethylurea-induced hamster neurofibromatosis model.

To investigate histogenesis of neurofibroma, early lesions of N-nitroso-N-ethylurea-induced neurofibroma of Syrian golden hamsters were examined. The lesions were detectable from 8 weeks of age, and a total of 14 lesions in 9 hamsters from 8 to 12 weeks of age were observed. Most of the lesions were found in the skin; they were also observed in the trigeminal nerve, cervical plexus, and abdominal sympathetic ganglion. Histological examination revealed there were two types of early lesions such as solitary and plexiform types. The former developed in the s.c. or dermal part of the skin and showed invasive growth of the surrounding tissue, while the latter originated from the large nerves such as the trigeminal nerve or cervical plexus. Growth kinetics of the early lesions was quantitated by continuous administration of bromodeoxyuridine and double immunostaining. Using these systems we observed that various kinds of cells had already participated in early lesions and later Schwann cells became a main component of the tumor. The histogenesis of neurofibroma was considered to be complexed by proliferation of several kinds of cell types at the early stage.

Animals↗
PubMed1988

Cellular differentiation and expression of matrix genes in type 1 neurofibromatosis.

The cellular heterogeneity of cutaneous tumors from nine patients with type 1 (von Recklinghausen's) neurofibromatosis was studied using several antigenic markers with special reference to focal heterotopic differentiation and interindividual variation. Furthermore, cells which actively express the genes for type I and III collagens and fibronectin, the major components of the abundant extracellular matrix of neurofibromas, were localized using in situ hybridizations. In eight of nine cases, the S-100 protein positive cells, i.e. Schwann-like cells, composed 60 to 80% of the total cell population. However, in one case, only about 40% of the cells were S-100 protein positive. The latter tumor was studied with respect to perineurial cell differentiation and stained with a mixture of two antibodies, directed against the S-100 protein and type IV collagen. In Schwann cells, the staining reaction for S-100 protein was observed in the nuclear region, whereas the staining reaction for type IV collagen was located peripherally, corresponding to the basement membrane zone covering the cells. The stromal cells which showed only the peripheral staining profile were considered to be neoplastic perineurial cells. Distinct structures with epithelial, endothelial, or smooth muscle cell differentiation were present within the benign tumors, as detected by immunostaining for cytokeratin, epithelial membrane antigen, factor VIII-related antigen and desmin, respectively. In situ hybridizations revealed a clearly detectable expression of type I procollagen genes in less than 10% and type III procollagen gene in less than 5% of the total cell population. Active synthesis of fibronectin was limited to the vascular walls, when examined by in situ hybridization, and antibodies to cellular fibronectin localized to the same areas. However, antibodies to plasma fibronectin produced a uniform staining reaction throughout the tumors suggesting that most of the fibronectin in neurofibromas is plasma-derived. The latter observation suggests that neurofibroma cells are freely accessible to various plasma proteins, including growth factors, which may influence the growth characteristics of these lesions.

Antibodies, Monoclonal↗
PubMed1989

[Segmental neurofibromatosis. Description of our 2d clinical case and review of the literature].

Segmental neurofibromatosis is characterized by the unilateral and segmental appearance of neurofibromas, schwannomas, plexiform neurofibromas and/or café au lait spots and axillary freckling. The aetiology is not clear but the disorder has been postulated to be secondary to a postzygotic (hence non-transmissable) somatic mutational event. In the present study we describe a 43 year old woman affected by neurofibromas on the left forearm. This is our second report of a case of segmental neurofibromatosis and occurs shortly afterwords the first. To the best of our knowledge only 28 additional cases of this very rare disease have been reported in the literature. Their main features are reviewed.

Adult↗
PubMed1987

[Incidence of the degeneration of cutaneous nerve tumors in Recklinghausen's disease].

A retrospective study was conducted in 85 patients with clinically certain von Recklinghausen's neurofibromatosis seen between 1972 and 1982. A similar study was conducted in 105 patients without neurofibromatosis observed during the same period who underwent excision of a cutaneous neurofibroma or schwannoma. Thirty-nine of the patients with neurofibromatosis never had surgical treatment for a nervous skin tumour; 46 had one or several tumours excised for diagnostic purposes or for cosmetic reasons. More than 300 tumours had been removed in these 46 patients. The post-operative follow-up period is now at least 2 years for all patients, 5 years for 85 p. 100 of them and more than 10 years for one-third. Only one case of malignant nervous skin tumour was observed in a patient who never had surgical treatment; it was a neurofibrosarcoma which resulted in death within two years. Two other deaths related to neurofibromatosis were recorded: one after surgical treatment of a duodenal schwannoma, the other due to septicaemia after infection of ulcers on a giant plexiform neurofibroma. Three other deaths unrelated to neurofibromatosis occurred. Local relapses without suspicion of malignancy were observed in 8 of the 46 surgical patients; 3 cases concerned large plexiform neurofibromas of the face; excision was histologically incomplete in most cases with or without relapse. No case of malignancy was recorded in the follow-up of the 105 patients without neurofibromatosis but with nervous skin tumours.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

[Neurofibromatosis associated with intra- and extracranial aneurysms and extracranial vertebral arteriovenous fistula].

Neurofibromatosis associated with vascular disorders is generally known as a vascular neurofibromatosis. In the neurosurgical aspect, it has been pointed out that "moyamoya disease" -like stenosis and/or occlusion of the internal carotid artery are seen in some of the patients with neurofibromatosis. This 58-year-old female with multiple café-au-lait spots and neurofibromas all over the body was admitted to our hospital with complaints of left orbital tumor and tinnitus. She had been suffering from the left intraorbital neurofibroma since ten years of age. Radiological examinations revealed left intraorbital neurofibroma extending into the intracranial cavity, multiple aneurysms and arteriovenous fistula. The aneurysms were located at the left vertebral-posterior interior cerebellar artery junction and at the extracranial internal carotid artery. The arterio-venous fistula was demonstrated at the left extracranial vertebral artery. Pathological changes of the blood vessels in the vascular neurofibromatosis are essentially obstructive lesions due to intimal thickening. Only few cases of neurofibromatosis associated with aneurysms and arteriovenous fistula have been reported, and eleven cases of them could be reviewed in the literature. Six are with intracranial aneurysms, two with extracranial aneurysms and three with extracranial vertebral arteriovenous fistula,. It is interesting that in all cases the extracranial vertebral arteriovenous fistula are located on the left side. This is corresponding to the fact that the bone defect around the asterion is predominantly seen on the left side in cases of neurofibromatosis.

Arteriovenous Malformations↗
PubMed1984

[Von Recklinghausen's neurofibromatosis and systemic mastocytosis].

We describe a 62-year-old woman who presented with a recurrent neurofibroma, two 'café-au-lait' spots and a possible cerebral tumor. This Von Recklinghausen neurofibromatosis was associated with an asymptomatic systemic mastocytosis with bone marrow involvement. We discuss Riccardi's recent theory on the pathogenesis of neurofibroma which postulates that the mast cells have a primordial role in the development of neurofibroma. Our observation could be additional evidence in favor of this theory.

Female↗
PubMed1980

Pathophysiology of neurofibromatosis. IV. Dermatologic insights into heterogeneity and pathogenesis.

A systematic, uniform evaluation of 102 patients with, or at risk for, neurofibromatosis has shown that café au lait spots (CLS), even in large numbers, may not be sufficient to diagnose this disorder, and that several other dermatologic features may provide clues to its pathogenesis. These features include pruritus associated with high concentrations of cutaneous neurofibromas, hyperpigmentation overlying plexiform neurofibromas, two levels of hyperpigmentation in some CLS, hypopigmentation in surgical scars through CLS, and areolar neurofibromas in postpubertal females. Iris Lisch nodules (hamartomas) are present in 97% of postpubertal patients.

Adolescent↗
PubMedDate not supplied

Morphology and distribution of eosinophilic granulocytes in damselfish neurofibromatosis, a model of mast cell distribution in neurofibromatosis type 1.

Mast cells (MC) are a conspicous component of neurofibromas in humans. The present study is based on damselfish neurofibromatosis (DNF) a naturally occurring animal model of neurofibromatosis type 1. Investigations of leukocytes of fishes have generally concluded that these animals lack metachromatic, basophilic mast cells and that the apparent analog in fishes is an eosinophilic granule containing cell (EGC). EGC were found at high densities in both naturally occurring neurofibromas in DNF and in those produced in laboratory transmission experiments. Tumors induced by injection of cells from cultured DNF tumor cell lines exhibited significantly higher densities of EGC than did spontaneously occurring tumors or those induced by injection of homogenized tumor tissue. EGC were significantly more common in the outer 200 microns edge of the tumors. We believe that these EGC are the piscine equivalent of the mammalian MC and that their presence in tumors in DNF will provide the first opportunity to experimentally manipulate this type of cell in neurofibromas.

Animals↗
PubMed1995

[Recurrent hemorrhage from the small intestine in a patient with type 1 neurofibromatosis].

Patients with NF-1 may exhibit visceral neurofibromas, Schwannomas and other tumors of ectodermal origin beside the classical cutaneous and neuronal manifestations of neurofibromatosis. In a 46-year-old woman with a previous diagnosis of NF-1 and a history of recurrent intestinal bleeding of obscure origin a well vascularized tumor in a branch of the A. messenterica superior was found by use of scintigraphy and angiography. Intraoperatively two inhomogeneons tumors were found in the proximal jejunum. Histologically these tumors were classified as neurofibromas. After partial resection of the jejunum no further intestinal bleeding occurred in this patient. Therefore the intestinal neurofibromas were presumably the source of the recurrent bleeding.

Angiography↗
PubMed1997

Bilateral segmental neurofibromatosis with partial unilateral lentiginosis.

A 73-year-old woman presented with numerous cutaneous neurofibromas on the trunk in a bilateral dermatomal distribution (T2-T12). She also had multiple lentigines scattered on the left side of the trunk, affecting the T2-T12 dermatomes. The diagnosis of bilateral segmental neurofibromatosis (NF) was made on the basis of the clinical features and distribution of the neurofibromas and an absence of family and systemic involvement. The pattern of lentigines was consistent with that of partial unilateral lentiginosis (PUL). Bilateral segmental NF is rare and 15 cases had been reported in the literature so far. This is the first reported case of a patient with bilateral neurofibromas and PUL.

Aged↗
PubMed1998

[Cutaneous-splanchnic neurofibromatosis].

BACKGROUND: Segmental neurofibromatosis (NF V) is ten times less frequent than Recklinghausen disease. Would the risk of visceral involvement in this uncommon form of neurofibromatosis warrant systematic imaging procedures? CASE REPORT: A 31-year-old man consulted for a voluminous plexiform neurofibroma in the left lumbar area. More ventrally, on the left side, there was also a café au lait spot. There were no Lisch nodules. The chest and abdominopelvic computed tomography and magnetic resonance imaging showed intramuscular tumoral extension, two neurofibromas in the 9th intercostal space and a voluminous 5-cm tumor situated in the left adrenal area. After resection pathology examination of the surgical specimen confirmed the diagnosis of ganglioneuroma. DISCUSSION: In this patient, all the neurofibromas and the café of lait spot developed in the territories of the left T10 and adjacent spinal roots. This was also true for the ganglioneuroma which developed on the deep sympathetic ramus to the adrenal gland which originates essentially from roots T8 to T11. This would place this case in the second subgroup of NF V in Roth's classification. Only six other cases have been reported in the literature. Such deep localizations are very likely to be underestimated, raising the problem of their detection and the correct protocol to follow asymptomatic forms, especially to detect disease progression to malignant degeneration which has a poor prognosis. Patients with a NF V should receive genetic counselling with a search for a family history, other signs of neurofibromatosis and Lisch nodules. In young patients, the risk of deep asymptomatic spread underlines the importance of regional computed tomographic or magnetic resonance explorations.

Adult↗
PubMed1978

[The problem of malignant degeneration in case of multiple neurofibromatosis (author's transl)].

Within less than one year, our hospital received three cases of malignant manifestation in case of multiple neurofibromatosis. If the histological findings and the neurogenic origin of the malignant tumor are evaluated very critically, the malignant suppression of the differentiation of one or more neurofibromas in case of multiple neurofibromatosis must be considered as occuring very rarely. If in case of a neurofibromatosis a malignant manifestation is found, it has to be examined very carefully by tissue specimens of numerous spots (Loehr and Willebrand), furthermore the neurogenic origin must be ensured (Zuelch). There are three clinical possibilities: 1. Sarcomatous degeneration of a neurofibroma with demonstrable neurogenic origin. 2. Histological appearence of a malignant suppression of the differntiation of a neurofibroma with benign clinical course. 3. Independent sarcoma as second disease without original connection to an existing multiple neurofibromatosis.--A critical evaluation of our cases showed that there was only one case of malignant tumor with neurogenic origin, namely a neurofibrosarcoma originating from a multiple neurofibromatosis.

Adult↗
PubMed2002

Orbitofacial masses in children: an endoscopic approach.

OBJECTIVE: To describe an endoscopic approach for pediatric orbitofacial masses. DESIGN: A retrospective medical chart review. SETTING: Tertiary-care children's hospital. PARTICIPANTS: Patients (4 boys, 7 girls) ranged in age from 6 months to 11 years. All children underwent endoscopic excision of an orbitofacial mass. INTERVENTION: A single port approach was used in all but the initial case. The scalp incision was placed approximately 2.0 cm behind the frontal hairline. A subgaleal dissection was performed to minimize risk of nerve injury. Under endoscopic visualization, the mass was resected. MAIN OUTCOME MEASURES: Ability to successfully excise the mass endoscopically, and the incidence of complication. RESULTS: All lesions were successfully resected endoscopically. The surgical time varied from 30 to 105 minutes (mean, 50.5 minutes). Pathologic examination revealed 10 dermoid cysts and 1 neurofibroma. Two children had transient frontalis branch palsies that resolved spontaneously. There was 1 unilateral frontal hypoesthesia in the patient with the neurofibroma (an expected result). There were no other complications. CONCLUSIONS: An endoscopic approach to pediatric orbitofacial tumors is safe and effective. Although the risk of nerve injury may be higher, a thorough knowledge of frontotemporal anatomy and careful dissection will minimize this risk. The distinct advantage of an endoscopic approach is the absence of any facial scar in these young patients.

Child↗
PubMed1978

Ultrastructural identification of a benign perineurial cell tumor.

A solitary tumor which by light microscopy was calssified as a neurofibroma was found by electron microscopic study to be composed of parallel, elongate cells with collagen rich intervening matrix. The cells showed thin, polar cytoplasmic processes which extended long distances, frequent junctional complexes between cell processes, numerous surface vesicles, and either no or fragmented and variable basement membrane. Perineurial cells from small peripheral nerves of skin were demonstrated to have similar morphologic characteristics as the tumor cells. The present study, together with previous ultrastructural findings, indicate that benign peripheral nerve sheath tumors should be placed in at least three categories: Schwannoma, neurofibroma and perineurioma.

Diagnosis, Differential↗
PubMed2001

CDKN2A germline splicing mutation affecting both p16(ink4) and p14(arf) RNA processing in a melanoma/neurofibroma kindred.

The CDKN2A locus encodes two tumor suppressor proteins, p16(ink4) and p14(arf), through use of alternative first exons. CDKN2A mutations detected in melanoma families are usually missense or nonsense changes which mainly impair p16(ink4) function. Large genomic deletions spanning the entire locus have been observed in two pedigrees with melanomas and nervous tumors. We have detected a novel splice site mutation in a family with melanomas, neurofibromas, and multiple dysplastic nevi. Both alternative mRNAs produced by the mutant allele lacked shared sequences from exon 2, which encodes a substantial portion (>50%) of both p16(ink4) and p14(arf) proteins. The development of neurofibromas can be explained by cooperative effects of combined inactivation of p16(ink4) and p14(arf) or, alternatively, of p14(arf) alone.

Adolescent↗
PubMedDate not supplied

MRI of pelvic neurofibromatosis.

Pelvic neurofibromatosis is a rare disease and rarely involves the prostate. A 19-year-old male presented with irritative and obstructive voiding symptoms. Magnetic resonance imaging showed a large mass extending from the sacral promontory to the perirectal and perivesical spaces and to the proximal root of the penis. The mass also involved the prostate. The characteristics of the mass were highly suggestive for neurofibroma. Prostate biopsy showed neurofibroma, and the immunohistochemistry stain for S-100 protein was positive.

Adult↗
PubMed1991

Magnetic resonance appearance of peripheral nerve sheath tumors.

Magnetic resonance imaging (MRI) was used to evaluate 22 histologically proven peripheral nerve sheath tumors, approximately two-thirds of which arose in the lower extremity. The histologic distribution was as follows: 12 schwannomas, 7 neurofibromas, and 3 malignant peripheral nerve sheath tumors (2 of which occurred in patients with neurofibromatosis). Most lesions demonstrated an intermediate to moderately bright signal on T1-weighted images and were minimally inhomogeneous. All lesions were moderately bright on proton-density-weighted images and bright on T2-weighted images, again with variable inhomogeneity. The extent of the tumor was best assessed on proton-density- and T2-weighted images. Smooth margins were noted in 19 lesions. Of the 3 remaining lesions, 2 were malignant (but had been subjected to biopsy prior to MRI), and the other lesion was a plexiform neurofibroma. MRI accurately determined the relationship between the lesion and the adjacent neurovascular structures and muscles, thereby assisting surgical management. On MRI, 5 lesions demonstrated coexistent subtle muscle atrophy along the longitudinal axis of surrounding or distally innervated musculature. This latter finding, together with the presence of a tumor in the vicinity of a large nerve trunk, suggests a peripheral nerve sheath neoplasm.

Adult↗
PubMed1989

Nerve growth factor receptor immunoreactivity in human benign peripheral nerve sheath tumor.

In situ expression of nerve growth factor (NGF) receptors in human dermal and plexiform neurofibroma, schwannoma and traumatic neuroma was examined by an immunohistochemical method using a monoclonal anti-human NGF receptor antibody. Immunoreactivity for the NGF receptor was observed on the principal cells of both neurofibroma and schwannoma. Immunostaining by the anti-S-100 beta protein antibody in adjacent sections suggested that the vast majority of NGF receptor-positive cells were also positive for S-100 beta protein. In traumatic neuroma, staining for the NGF receptor was more intense in the perineurium than in the endoneurial cells.

Adult↗