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PubMedDate not supplied

Immunohistochemical studies of S100 protein and other neural characteristics expressed by granular cell tumour.

Eight cases of granular cell tumour (GCT), five Schwannomas and two neurofibromas were examined immunohistochemically for the presence of S100 protein, neurofilament protein (NP), epidermal growth factor (EGF) and glial fibrillary acidic protein (GFAP). The solochrome cyanin stain for myelin was also applied. All cases of GCT showed staining for S100 protein. Focal positivity was seen in Schwannomas and neurofibromas. Stains for EGF, GFAP, NP and solochrome cyanin were negative. S100 is a marker for Schwann cells. The expression by GCT of S100 supports a neural genesis of GCT.

Brain Chemistry↗
PubMed1978

Scanning electron microscopy of nerve sheath neoplasms.

Neurofibromas and schwannomas were clearly differentiable by scanning electron microscopy of thin microscopic sections. Neurofibromas exhibited ordered laminations of collagen with scattered fibroblast-like cells interspersed. Schwannomas contained proliferations of smooth tube-forming cells. These neoplastic characteristics were compared with cellular characteristics of normal nerve sheaths to determine the cell of origin in each neoplasm.

Animals↗
PubMed1981

Becker's melanosis: an organoid hamartoma.

Herein we have reported the histologic findings in two cases of Becker's melanosis. In one patient the lesion showed hyperplasia or hair muscles and in the other patient the lesion was associated with an underlying neurofibroma. The proliferative changes seen in the epidermis and dermis in Becker's melanosis can best be explained by the concept of an organoid hamartoma with involvement of the epidermis, pilar structures, and some other dermal components. The localization of the plexiform neurofibroma within the Becker's nervus is a unique observation. It may fall within the spectrum of an organoid hamartoma or it may only represent a chance occurrence.

Adult↗
PubMed1995

Neurofibromatosis.

The neurofibromatoses are defined by the presence of café-au-lait macules and neurofibromas and are associated with central and peripheral nervous system tumors. Individuals with neurofibromatosis 1 are at risk for optic nerve gliomas, nerve root and plexi neurofibromas and schwannomas, spinal cord tumors, benign and malignant peripheral nerve sheath tumors, and pheochromocytomas. Individuals with neurofibromatosis 2 are at risk for presenile cataracts, vestibular schwannomas, intracranial and intraspinal meningiomas, and intramedullary spinal cord ependymomas.

Child↗
PubMed1995

MR in neurofibromatosis of the larynx.

We report the MR results of four patients with plexiform neurofibromas of the larynx. Three had irregular margins and were circumferential around the airway. The distinction between regularly and irregularly shaped neurofibromas may have implications for symptom onset.

Biopsy↗
PubMed1994

Optic gliomas in neurofibromatosis type 1 (NF-1). Presentation of 31 cases.

We present a series of 31 cases of optic glioma associated with neurofibromatosis type 1 in patients under 11 years of age. They represent 64% of all the optic gliomas seen in our service between September 1965 and September 1993. The optic nerves were affected in 25 cases (83%); 9 children (30%) had a isolated, unilateral tumor; 16 (53%) had involvement of the optic chiasm as well as of one or both optic nerves. In 6 cases (19%) only the chiasm was affected, with or without involvement of other intracerebral structures. A coincidental orbital plexiform neurofibroma was associated with a poor prognosis. Other complications included 8 cases (26%) presenting with slowly developing aqueductal stenosis requiring treatment with a shunt. High-resolution computed-tomographic scans provided well-defined images for the diagnosis of optic nerve glioma, but magnetic resonance imaging was the preferred procedure for the diagnosis of gliomas involving the chiasm and the optic tracts and radiations, particularly if there was no mass effect. In our patients, tumor growth was hardly noticeable during follow-up even up to 20 years, with no difference between patients who were treated with radiation and those who were not treated. However, endocrine disturbances developed in all cases subjected to radiotherapy, and were less frequent in untreated patients. Aqueductal stenosis was observed with similar frequency among both treated or untreated patients. Three patients died, two due to complications of hydrocephalus secondary to aqueductal stenosis and one because of respiratory problems due to compression of the hypothalamus and brainstem by the chiasm tumor. Two of the 3 patients who died had orbital plexiform neurofibroma.

Age Factors↗
PubMed1993

[Peripheral neurogenic tumors--surgical therapy of nerve sheath tumors. Review and personal results].

Nerve sheath tumors are rare tumors originating from the Schwann's cover cells. Neurinomas, neurofibromas and schwannomas can be separated due to a diverse growth behavior. 24 patients with neurinomas and 13 patients with neurofibromas were operated on from January 1, 1987 to December 31, 1992 at the Department of Surgery, University Cologne. A total of 10 patients received treatment during the last ten years because of schwannoma. The concepts of treatment and differentiation of the various tumors are demonstrated and compared based on the patients records and on a review of the literature.

Adolescent↗
PubMedDate not supplied

[Isolated and spontaneously regressive colonic neurofibromatosis].

This case report concerns a man presenting protein losing enteropathy. Multiple polypoid colonic lesions were discovered corresponding to intra and submucosal neurofibromas. No extradigestive sign was noticed, and the diagnosis of isolated colonic neurofibromatosis was upheld. Eight years later, it was observed that both protein losing enteropathy and the colonic neurofibromas had apparently spontaneously disappeared. Isolated digestive neurofibromatosis and spontaneous tumoural regressions are discussed.

Colonic Neoplasms↗
PubMed1997

A potential role for NF1 mRNA editing in the pathogenesis of NF1 tumors.

Neurofibromatosis type I (NF1) is a common disorder that predisposes to neoplasia in tissues derived from the embryonic neural crest. The NF1 gene encodes a tumor suppressor that most likely acts through the interaction of its GTPase-activating protein (GAP)-related domain (GRD) with the product of the ras protooncogene. We have previously identified a site in the NF1 mRNA, within the first half of the NF1 GRD, which undergoes base-modification editing. Editing at that site changes a C to a U, thereby introducing an in-frame stop codon. NF1 RNA editing has been detected in all cell types studied, to date. In order to investigate the role played by editing in NF1 tumorigenesis, we analyzed RNA from 19 NF1 and 4 non-NF1 tumors. We observed varying levels of NF1 mRNA editing in different tumors, with a higher range of editing levels in more malignant tumors (e.g., neurofibrosarcomas) compared to benign tumors (cutaneous neurofibromas). Plexiform neurofibromas have an intermediate range of levels of NF1 mRNA editing. We also compared tumor and nontumor tissues from several NF1 individuals, to determine the extent of variability present in the constitutional levels of NF1 mRNA editing and to determine whether higher levels are present in tumors. The constitutional levels of NF1 mRNA editing varied slightly but were consistent with the levels observed in non-NF1 individuals. In every case, there was a greater level of NF1 mRNA editing in the tumor than in the nontumor tissue from the same patient. These results suggest that inappropriately high levels of NF1 mRNA editing does play a role in NF1 tumorigenesis and that editing may result in the functional equivalent of biallelic inactivation of the NF1 tumor suppressor.

Astrocytoma↗
PubMed1997

Soft tissue tumours of eyelid.

Soft tissue tumours of eyelid constituted 28.9% of all eyelid tumours. Morphologically they were either vascular 32 cases (49.23%), neural 24 cases (36.92%), fibrous 6 cases (9.23%) or adipose tissue tumours 3 cases (4.62%). The age ranged from 1-30 years, haemangiomas and neurofibromas were present since birth. Upper eyelid was involved in 81.54% cases. Neurofibroma was associated with generalized lesions in 13.6% cases.

Adipose Tissue↗
PubMed1998

[Cutaneous manifestations of type 1 neurofibromatosis and their treatment].

After recalling the frequency and pathophysiology of type 1 neurofibromatosis, or Von Recklinghausen disease, the authors report the various cutaneous manifestations: café-au-lait spots, lentigines, cutaneous neurofibromas, plexiform neurofibromas. Treatment must be multidisciplinary, as surgery is difficult and often gives disappointing results. The various surgical treatments are considered according to the type and site of the lesions to be treated, with particular emphasis on the treatment plan, which must be discussed with the patient.

Adolescent↗
PubMed1997

Malignant peripheral nerve sheath tumor: a fine-needle aspiration biopsy study.

Although the histopathologic features of malignant peripheral nerve sheath tumors (MPNST) have been well-described, the cytologic features are less well-characterized. We retrospectively reviewed 4 aspiration specimens from 3 patients with histologically-proven MPNST. The biopsy specimens were obtained from the primary tumor (1 case), a local recurrence (2 cases), and a pulmonary metastasis (1 case). The patients were women, aged 42, 61, and 70 yr. The primary tumors arose from the left neck and elbow, and from a neurofibroma in the right medial thigh. The latter patient had von Recklinghausen's disease. Cardinal cytomorphologic features included aggregates and single cells with ovoid to elongated, and comma to serpentine shapes, as well as hyperchromatic nuclei surrounded by delicate, tapering cytoplasm. Nuclear pleomorphism ranged from slight to marked. Multinucleated giant cells were seen in 2 cases. In general, the degree of nuclear variability within each individual case exceeded that typically observed with synovial sarcoma or fibrosarcoma. Although the cytomorphologic features may strongly suggest MPNST, clinical correlation is necessary and immunocytochemistry (i.e., S-100 protein) may help to distinguish MPNST from other spindle-cell sarcomas. Origin from a nerve trunk or preexisting neurofibroma, or occurrence in a patient with von Recklinghausen's disease, confirms the diagnosis of MPNST.

Adult↗
PubMed1997

Subglottic nerve sheath tumor in a pediatric patient: case report and literature review.

BACKGROUND: Although nerve sheath tumors (neurilemmoma and neurofibroma) can occur on any nerve with Schwann cells, laryngeal involvement is very uncommon. The vast majority of reported laryngeal nerve sheath tumors have been located in the supraglottic area. Our case report involves the diagnosis and management of a subglottic nerve sheath tumor in a pediatric patient. Only two previous reports of such a lesion appear in the world literature. METHODS: A 12-year-old girl was initially seen by her allergist for evaluation of a 2-month history of wheezing and nocturnal dyspnea. Therapy with bronchodilators and steroids had limited success. Flow-volume loop studies suggested a fixed upper airway obstruction, and an office laryngoscopy identified a cherry red, submucosal subglottic lesion. Magnetic resonance imaging (MRI) scan verified the presence of a smooth, homogeneous subglottic mass. RESULTS: An endoscopic CO2 laser excision of the lesion was performed using jet ventilation technique. Histopathology determined the lesion to be a nerve sheath tumor (neurilemmoma versus neurofibroma). Postoperatively, the patient has been asymptomatic without evidence of recurrence. CONCLUSIONS: A subglottic nerve sheath tumor in a pediatric patient is very rare. Although endoscopic and open approaches have been advocated, CO2 laser with jet ventilation provided an excellent modality for resecting this lesion.

Child↗
PubMed1995

Cutaneous plexiform schwannoma associated with neurofibromatosis type 2.

BACKGROUND: Plexiform schwannoma (PS) is a rare benign tumor of the nerve sheath that can be located either in the deep soft tissues or in the dermis or subcutis. The tumor predominantly affects young adults and occurs most commonly as a slowly growing asymptomatic solitary nodule in the head and neck region, trunk, and upper extremities. METHODS: A cutaneous PS located in the preauricular region of a 19-year-old white female is reported. The patient exhibited six "café-au-lait" spots in the trunk and the extremities. Magnetic resonance imaging examination showed bilateral tumors in both acoustic nerves (considered schwannomas) and also masses in the right major sphenoidal wing, falx, and T2-T3 level of rachis and a solid and cystic tumor in the low medulla oblongata. Tumors of the preauricular region, medulla oblongata, spinal cord at level T2-T3, and major sphenoidal wing area were surgically removed. The tumors were studied by immunohistochemistry and diagnosed as PS, pilocytic astrocytoma, and meningiomas, respectively. RESULTS: Seventy-eight cases of PS have been reported in the literature: 8 (10.2%) have been associated with clinical schwannomatosis, 6 (7.7%) with multiple cutaneous schwannomas syndrome, and only 3 (3.8%) with neurofibromatosis type 1 (NF-1). CONCLUSIONS: In this report, to the authors' knowledge, for the first time PS is described associated with neurofibromatosis type 2. The tumor does not appear to have significant association with NF-1. Plexiform schwannoma should be recognized because it may be misdiagnosed as plexiform neurofibroma or other plexiform malignant tumors. Differentiation from plexiform neurofibroma is important, because the latter is virtually pathognomonic of neurofibromatosis type 1 and has a propensity for malignant transformation.

Adult↗
PubMed2000

Mast cells migrate, but do not degranulate, in response to fractalkine, a membrane-bound chemokine expressed constitutively in diverse cells of the skin.

Mast cells (MC) are anatomically located near nerves and blood vessels in skin and the gastrointestinal tract and tend to localize within certain cutaneous tumors such as neurofibromas. However, the molecular mechanisms by which MC home to these sites are not well characterized. Fractalkine (FK) is a membrane-bound CX3C chemokine that displays constitutive expression in dendritic cells as well as in non-hematopoietic tissues including mammalian brain. Here we show that FK is constitutively expressed by skin endothelial cells, dermal dendrocytes and cells within neurofibromas. By reverse transcription-PCR, FK receptor, CX3CR1, is expressed by cultured murine bone marrow-derived MC (BMMC) of both connective tissue and mucosal phenotypes. Non-activated human dermal MC isolated from neonatal foreskin similarly demonstrated CX3CR1 expression. In chemotaxis assays, FK attracted MC with maximal migration occurring between 25 - 125 ng / ml. BMMC were not stimulated to release proinflammatory mediators in the presence of FK as measured by granule-associated beta-hexosaminidase release. Thus, CX3CR1 is expressed by MC and effectively mediates chemotaxis without inducing degranulation. We propose that the constitutive expression of FK on certain cells in the skin may be a factor in the tissue-specific homing of MC.

Animals↗
PubMed1995

Clitoromegaly in neurofibromatosis.

Genitourinary neurofibromas are rare and clitoral involvement in neurofibromatosis (NF) has been reported infrequently. However, when it occurs, clitoromegaly is often the presenting sign. In many cases, it is congenital. In 236 families with type 1 neurofibromatosis (NF-1) evaluated through the USF Regional Genetics Program between January 1982 and September 1993, four patients had clitoral involvement. In three, involvement was limited to the clitoris. Biopsy/surgical excision in two of them showed a neurofibroma in one and non-specific hamartomatous soft tissue overgrowth in the other. In the fourth patient, the involvement was asymmetric and extended to the labia majora and mons pubis. Endocrine studies and chromosomes in all patients were normal; there was no exposure to androgens, progestins, or coumadin. There was no gestational history of maternal luteomas. Review of the literature documented 26 patients with NF and clitoral involvement. Clitoral involvement in NF-1 appears to be more common than previously reported and the differential diagnosis of ambiguous genitalia should include clitoromegaly due to NF. Pathogenesis of clitoral lesions appears similar to other lesions of NF. Biopsy of such lesions appears to be justified only when malignancy is suspected.

Child↗
PubMed1995

Deletion of the entire NF1 gene detected by the FISH: four deletion patients associated with severe manifestations.

Genetic analysis of NF1 has indicated a wide diversity of mutations, including chromosome rearrangements, deletions, insertions, duplications, and point mutations. Recently, five severely affected individuals have been found by Kayes et Al. [1994] to have deletions encompassing the entire gene. These deletions were detected by quantitative Southern analysis. To simplify deletion detection, we have employed fluorescence in situ hybridization (FISH) using intragenic probes. Thirteen unrelated individuals with NF1 have been studied. Among six with severe manifestations, four have been found to have deletions detected by probes cFF13, cFB5D, cP5, yA43A9, yA113D7 and yD8F4. All four deletions patients have severe developmental delay, minor and major anomalies (including one with bilateral iris colobomas), and multiple cutaneous neurofibromas or plexiform neurofibromas which were present before age 5 years. FISH provides a simple and rapid means of identification of NF1 gene deletions and will allow more rigorous testing of the hypothesis that such deletions are associated with severe manifestations.

Abnormalities, Multiple↗
PubMed2006

Non-random associations and vascular fields in neurofibromatosis 1: a pathogenetic hypothesis.

Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder with highly variable expression generally ascribed to random factors. However, evidence is presented for patterns suggesting non-stochastic processes as follows: (1) We have seen a MZ twin pair concordant for renal vascular hypertension, and another for unilateral ptosis. Other concordances have been reported, including both malformations and tumors, and combinations as well. (2) Four children were seen with a distinct ipsilateral association of glaucoma or iris anomaly, optic glioma, plexiform neurofibromas arising from the trigeminal nerve and its branches, and sphenoid dysplasia. Other cases in the literature support milder forms of this association. (3) We saw six children with apparent gynecomastia or premature thelarche without endocrine abnormalities. Tissue samples from four of these showed an unusual fibrous plexiform neurofibroma. Interestingly, five of the six cases were African Americans, and constitutional factors affecting fibrous reactions may also be involved here.A tentative hypothesis is presented suggesting vascular fields involving defined areas that can: (1) Support tumor growth. They would be the "soil" determining the ability and the extent of growth. There would, however, still be a need for a "second hit" tumor transformation. (2) Affect blood supply to organs, creating structural anomalies. NF1 involves a vasculopathy, and would predispose to vulnerabilities of such fields. Genetic factors could induce superimposed susceptibilities of specific fields, leading to twin concordances. "Hits" affecting specific fields would increase the likelihood of multiple abnormalities that could include both tumors and structural findings. Finally, tumors may follow the contours of existing fields. The breast is an area normally primed for growth, and the observation of clitoromegally secondary to tumor involvement suggests that such fields exist elsewhere.

Child↗