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Results for “Neurofibroma, Plexiform”

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At least 19 recordsLinked to original sources
PubMed1999

Plexiform neurofibromas.

Plexiform neurofibromas are among the most common and debilitating complications of neurofibromatosis type 1 (NF1). They account for substantial morbidity, including disfigurement, functional impairment, and may even be life threatening. Plexiform neurofibromas are also subject to transformation into malignant peripheral nerve sheath tumor (MPNST), a complication that is refractory to treatment both because of a paucity of effective therapies for malignant soft tissue sarcomas in general, and because of the delay in diagnosis that results from change of a small portion of a large pre-existing tumor. The current mainstay of treatment of plexiform neurofibromas, and of MPNST for that matter, is surgical resection. The major variables are the timing and means of identification of plexiform neurofibromas, methods of follow-up, and indications for surgery. There is no established means of medical treatment, but research into the molecular pathogenesis of NF1, as well as advances in tumor therapy in general, are opening the way towards clinical trials for plexiform neurofibroma. Am. J. Med. Genet. (Semin. Med. Genet.) 89:31-37, 1999.

Humans↗
PubMed2003

Malignant peripheral nerve sheath tumours in neurofibromatosis type 1: MRI supports the diagnosis of malignant plexiform neurofibroma.

Plexiform neurofibroma (PNF) is a typical feature of neurofibromatosis 1 (NF1). About 10% of patients with NF1 develop malignant peripheral nerve-sheath tumours (MPNST), usually arising from PNF, and this is the major cause of poor survival. A better prognosis can be achieved if the tumours are diagnosed at an early stage. Our objective was to establish MRI criteria for MPNST and to test their usefulness in detecting early malignant change in PNF. MRI was performed on 50 patients with NF1 and nerve-sheath tumours, of whom seven had atypical pain, tumour growth or neurological deficits indicative of malignancy; the other 43 were asymptomatic. On MRI all seven symptomatic patients had inhomogeneous lesions, due to necrosis and haemorrhage and patchy contrast enhancement. In one patient, the multiplicity of confluent tumours with inhomogeneous areas in addition to central lesions did not allow exclusion of malignancy. Only three of the 43 asymptomatic patients had comparable changes; the other 40 patients had tumours being of relatively homogeneous structure on T1- and T2-weighted images before and after contrast enhancement. All three asymptomatic patients with inhomogeneous lesions were shown to have MPNST.

Adolescent↗
PubMed2006

Single stage near total resection of massive pediatric head and neck plexiform neurofibromas.

OBJECTIVE: Plexiform neurofibromas of the head and neck in neurofibromatosis type 1 (NF 1) carry a significant morbidity with substantial loss of function as well as significant cosmetic problems. We describe our experience with early aggressive surgical intervention in such patients in order to avert these problems. METHODS: Retrospective review of four consecutive pediatric patients with massive head and neck plexiform neurofibromas who underwent single stage near total or sub-total tumor resections. RESULTS: All four patients were referred for obstructive airway symptoms. Each patient experienced complete relief of symptoms and return of function without additional neurological deficits. There were two minor complications and no major complications of surgical resection. There have been no recurrences to date, with follow-up ranging from 15 months to 5 years. CONCLUSIONS: Early surgical intervention of NF 1 patients with plexiform neurofibromas of the head and neck with a goal of near total resection avoids the loss of function associated with these tumors, such as tracheostomy dependence, swallowing difficulty, and speech problems, and prevents the inexorable progression of substantial cosmetic deformity. Successful management of these complex lesions requires detailed preoperative planning, advanced surgical techniques, and vigilant postoperative care.

Adolescent↗
PubMed1997

Massive intratumor hemorrhage in facial plexiform neurofibroma.

BACKGROUND: Plexiform neurofibromatosis is a feature of von Recklinghausen's disease. Head and neck lesions may produce varying degrees of cosmetic and functional deformity. However, life-threatening hemorrhage into facial plexiform neurofibromas has not been previously reported. METHOD: We report two patients with von Recklinghausen's disease who experienced massive hemorrhage into facial neurofibromas, one following a blunt injury and the other without a known initiating event. RESULTS: Conservative management did not stop the hemorrhage into facial neurofibromas in either instance. Surgical exploration was mandated for hemorrhage control and evacuation of blood clots. Hemostasis was attained by a combination of hypotensive anesthesia and chromic catgut suture ligatures. CONCLUSIONS: These case reports demonstrate a potentially lethal complication in patients with facial plexiform neurofibroma. Where a competent and experienced interventional neuroradiologist is not available, surgical exploration should be undertaken to control bleeding.

Adolescent↗
PubMed2004

Molecular profiles of neurofibromatosis type 1-associated plexiform neurofibromas: identification of a gene expression signature of poor prognosis.

PURPOSE: Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder with a complex variety of clinical symptoms. The hallmark of NF1 is the development of heterogeneous benign neurofibromas, which may appear as dermal neurofibromas or plexiform neurofibromas. NF1 patients with plexiform neurofibromas are at risk of developing malignant peripheral nerve sheath tumors. EXPERIMENTAL DESIGN: To obtain additional insight into the molecular pathogenesis of plexiform neurofibromas, we used real-time quantitative reverse transcription-PCR assays to quantify the mRNA expression of 349 selected genes in plexiform neurofibromas in comparison with dermal neurofibromas and patient-matched malignant peripheral nerve sheath tumors. RESULTS: Thirty genes were significantly up-regulated in plexiform neurofibromas compared with dermal neurofibromas. None were down-regulated. The up-regulated genes mainly encoded transcription factors and growth factors and secreted proteins, cytokines, and their receptors, pointing to a role of paracrine and autocrine signaling defects in the genesis of plexiform neurofibromas. We also identified a gene expression profile, based on MMP9, FLT4/VEGFR3, TNFRSF10B/TRAILR2, SHH, and GLI1, which discriminated those plexiform neurofibromas most likely to undergo malignant transformation. CONCLUSION: Our study has identified a limited number of signaling pathways that could be involved, when altered, in plexiform neurofibroma development. Some of the up-regulated genes could be useful diagnostic or prognostic markers or form the basis of novel therapeutic strategies.

Adolescent↗
PubMed1996

Plexiform leiomyoma of the esophagus: a peculiar gross variant simulating plexiform neurofibroma.

A plexiform variant of leiomyoma of the esophagus in a 51-year-old woman is reported. The patient was diagnosed with a tumor of the esophagus in an X-ray mass survey of the upper gastrointestinal tract. She was referred to the Ryukyu University Hospital for further examination. She appeared healthy with no complaints. Upper gastrointestinal series revealed an oval, well-defined filling defect in the lower esophagus just above the esophagogastric junction. Endoscopy revealed an undulating bulge covered with normal esophageal mucosa. Endoscopic ultrasonography showed a sharply demarcated hypoechoic mural tumor with internal linear pattern, with no evidence of penetration into the surrounding tissue. These findings were evaluated as consistent with a leiomyoma. Removing the tumor by enucleation was easily accomplished. Unexpectedly, on gross inspection, the tumor was a plexiform type, mimicking a plexiform neurofibroma. Light and electron microscopic examination and immunohistochemistry of the tumor tissue confirmed leiomyoma. Since the enucleation of the tumor, the patient has been free of recurrence and symptoms for 1.5 years at the time of this report.

Diagnosis, Differential↗
PubMed1977

Facial plexiform neurofibroma.

Facial plexiform neurofibroma is a relatively rare manifestation of Von Recklinghausen's neurofibromatosis. Two patients with extensive facial tumor involvement are presented, each having undergone wide local resection after multiple previous local excisions had failed to control the tumor and its locally deforming and destructive effects. A discussion of the problem, its etiology, pathogenesis, natural history, prognosis and suggested treatment is presented.

Adolescent↗
PubMed1979

Epicranial plexiform neurofibroma.

Epicranial plexiform neurofibroma is a rare presentation of neurofibromatosis. Two such cases are presented in which epicranial tumors constituted isolated manifestations of the disease except for skin pigmentation. Tumor development began at two and three months of age respectively; one case showed a calvarian bony defect associated with the tumor.

Female↗
PubMed1995

[Exclusive nodular plexiform neurofibroma. An unusual case of neurofibromatosis type 1].

INTRODUCTION: Type 1 neurofibromatous tumours (NF) are benign skin tumours which include cutaneous, subcutaneous and plexiform neurofibromas. Plexiform neurofibromas are either diffuse or nodular, the latter form being much more frequent. CASE REPORT: We observed a particular form of neurofibroma in an 18-year-old patient who developed large deep subcutaneous which histology examination revealed to be exclusively nodular plexiform neurofibromas. The patient also had 6 café au lait spots leading to the diagnosis of sporadic NF 1. He did not have acoustic neuronoma, schwannoma or posterior cataract, eliminating NF 2. COMMENTS: In NF 1, subcutaneous neurofibromas develop in 5 p. 100 of the patients. These lesions are termed nodular plexiform neurofibromas when they form long formations along nerve branches. The exclusive nature of the nodular plexiform neurofibromas in our case was exceptional. It could be hypothesized that the particular phenotype in our patient might correspond to a particular anomaly of the NF 1 gene.

Adolescent↗
PubMed1996

Airway obstruction in children due to plexiform neurofibroma of the larynx.

Plexiform neurofibroma of the larynx is a rare disease. Three cases in children with airway obstruction are presented. After tumour reduction via a lateral pharyngotomy their tracheostomies could be closed. The surgical treatment of plexiform neurofibroma of the superior laryngeal nerve is discussed and conservative, subtotal resection is recommended.

Airway Obstruction↗
PubMed1999

Allelic loss of the NF1 gene in NF1-associated plexiform neurofibromas.

Neurofibromatosis 1 (NF1) is an autosomal dominant disorder with a complex variety of clinical symptoms. Genetic alteration of the NF1 gene on 17q11.2 is the disease. Neurofibromas of the peripheral nervous system are one main manifestation. A variant of neurofibroma is the plexiform neurofibroma which can be found in about 30% of NF1-patients, often causing severe clinical symptoms. In this study, we examined 14 such tumors from 10 NF1-patients for allele loss of the NF1 gene (LOH: loss of heterozygosity) using four intragenic polymorphic markers. Loss of heterozygosity was found in eight tumors from five patients, and suspected in one additional tumor from another patient. This finding suggests that loss of the second allele, and thus inactivation of both alleles of the NF1 gene, is associated with the development of plexiform neurofibromas. The 14 plexiform neufibromas were also examined for mutation in the TP53 gene by screening exons 5 through 8 using temperature gradient gel electrophoresis. No mutation was found in any of the tumors.

Adult↗
PubMed2004

Plexiform neurofibromas express the transcription factor Gli1.

BACKGROUND: Plexiform neurofibromas occur commonly in individuals with neurofibromatosis type 1 (NF1) and consist of neurofibromatous change in multiple nerve fascicles. Previously, we had observed that both plexiform neurofibromas and normal cutaneous nerves expressed Hedgehogs (Hhs), which are intercellular signaling molecules and regulate growth and patterning during embryonic development, and their receptors. In the present study, we examined the expression of Gli1, a transcription factor which mediates Hh signaling to investigate the activation of Hh signaling in plexiform neurofibromas and normal cutaneous nerves. METHODS: An antihuman Gli1 antibody was used with a standard immunoperoxidase technique to determine Gli1 expression in 5 specimens of plexiform neurofibromas and 5 specimens of normal cutaneous nerves. RESULTS: Our results showed Gli1 expression in S-100-positive tumor cells within the involved nerve fascicles in plexiform neurofibromas but not in control normal skins. CONCLUSIONS: Our findings indicate that the Hh signaling pathway is activated in plexiform neurofibromas.

Biomarkers, Tumor↗
PubMedDate not supplied

Plexiform neurofibroma of the tongue: a case report of a child.

A three-year-old girl with a lingual plexiform neurofibroma treated by total excision is presented. Despite their occurrence in the head and neck region, neural sheath tumors are rarely encountered in the oral cavity. It is reported that 4-7% of patients affected by neurofibromatosis display oral manifestations. Neurofibromatosis is characterized by café-au-lait spots and cutaneous neurofibromas. Plexiform neurofibroma is said to be indicative of von Recklinghausen's disease (VRD) even though it may be the only manifestation of the disease. Generally, surgical resection represents the treatment of choice and the diagnosis can only be confirmed after histological examination. Affected patients need regular follow-up to detect malignant degeneration, an early recurrence or appearance of other manifestations of VRD.

Cafe-au-Lait Spots↗
PubMed1985

An isolated plexiform neurofibroma of the bladder.

Plexiform neurofibroma of the bladder is rare, and is considered an expression of the syndrome of neurofibromatosis (von Recklinghausen's disease). We report a case of a vesical plexiform neurofibroma with no other apparent stigmas of the syndrome. The variable natural course of the disease is demonstrated.

Adult↗
PubMed1994

Retroperitoneal plexiform neurofibromas: CT findings.

OBJECTIVE: CT findings in retroperitoneal plexiform neurofibromas have been described previously only in a few case reports. This study was performed to characterize the CT features in a larger group of patients with this benign neoplasm and to delineate those findings that suggest the presence of concurrent malignant tumors of the nerve sheath. MATERIALS AND METHODS: From a review of CT scans showing retroperitoneal masses in 25 patients with neurofibromatosis type 1, we identified 16 patients whose clinical and CT features suggested the diagnosis of plexiform neurofibromas. The diagnosis was confirmed by biopsy of the mass in three patients. In the remaining 13 patients, the diagnosis was supported by long-term follow-up in eight and by biopsy confirmation of either a neurofibroma or a plexiform neurofibroma elsewhere in the body in the other five patients. Concurrent retroperitoneal malignant tumors of the nerve sheath were confirmed by biopsy in five patients. RESULTS: CT showed bilateral, remarkably symmetric masses extending along the medial and posterior aspects of the psoas muscles in 15 of the 16 patients. Parapsoas masses tended to be long and cylindrical. In addition to parapsoas masses, eight patients had bilateral, symmetric masses extending along the anterior aspect of the sacrum in a sheetlike fashion. Masses were identified in the region of the celiac axis and the origin of the superior mesenteric artery in four patients. Only one patient had an isolated celiac/superior mesenteric artery mass without associated parapsoas or presacral masses. Retroperitoneal masses were of homogeneous, low attenuation when compared with adjacent muscle on CT images of 14 patients. Two patients had an unusual swirling and serpiginous pattern of increased attenuation superimposed on a low-attenuation background. Asymmetry in size and attenuation was due to malignant nerve sheath tumors in five patients. CONCLUSION: Retroperitoneal plexiform neurofibromas have a characteristic appearance on CT scans. They are typically bilateral, symmetric, low-attenuation masses in a parapsoas or presacral location. Asymmetry in size and attenuation of a larger mass suggests the possibility of a malignant tumor of the nerve sheath. Recognition of the CT features of a retroperitoneal plexiform neurofibroma can obviate the expense, pain, and risk of an unnecessary biopsy. Conversely, detection of findings suggestive of malignant tumor can lead to appropriate recommendation of biopsy.

Adult↗
PubMed2005

Subtotal and total resection of superficial plexiform neurofibromas of face and neck: four case reports.

INTRODUCTION: Plexiform neurofibromas are benign tumours of the peripheral nerves and connective tissue. They develop most often in patients with neurofibromatosis type 1 (NF1) and often grow continuously. Removal of plexiform neurofibromas is usually unsatisfactory because the network-like growth of these tumours often involves multiple nerve fascicles and other adjacent tissues. It has been previously shown that magnetic resonance tomography can distinguish the growth patterns of plexiform neurofibromas into three different categories: superficial, displacing and invasive. PATIENTS AND METHODS: Three cases are described with successful subtotal resections of superficial plexiform neurofibromas, and one case with total resection following the diagnosis of tumour subtype using magnetic resonance imaging (MRI). RESULTS: There was a significant, lasting improvement in appearance which demonstrates that surgical intervention in the case of superficial plexiform neurofibroma is valuable. CONCLUSION: Careful classification of plexiform neurofibroma by means of MRI provides valuable information for the surgical management of patients. It enables the distinction to be drawn between this subtype and the other two subtypes of plexiform neurofibromas.

Adolescent↗
PubMed2005

Plexiform neurofibroma of the cauda equina: case report.

BACKGROUND: Plexiform neurofibromas are rarely found in the cauda equina. The most recent report of a plexiform neurofibroma of the cauda equina noted only 2 previously described cases. CASE DESCRIPTION: To these we add the current case, as well as 2 additional previously published cases. We report the case of a 44-year-old man with a sudden exacerbation of his long-standing lower-back and bilateral leg pain. An intradural lesion was seen on magnetic resonance imaging and he underwent surgery. Intraoperatively, there were swollen nerve roots and tumor insinuating itself between the roots. A biopsy was performed, and pathology findings were consistent with plexiform neurofibroma. CONCLUSIONS: Plexiform neurofibroma of the cauda equina is a rare tumor, with variable manifestations. These tumors are not amenable to complete resection. Surgical treatment consists of either partial resection or biopsy, possibly with dural grafting for decompression.

Adult↗