• Korean Journal of Head & Neck Oncology
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• v.39 no.2
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• pp.45-48
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• 2023

Malignant peripheral nerve sheath tumor (MPNST) is one of the soft tissue sarcoma believed to originate from neural crest cells. The patients with neurofibromatosis type I (NF1) have about 8-13% of the lifetime risk of the malignant transformation. Neurofibroma on patients with NF1 can be surgically resected and has good prognosis if approach to the tumor is possible. We experienced a case of a 50-year-old woman with NF who had incompletely resected neurofibroma, which presented a rapid malignant transformation to MPNST, 3 months after the first surgery. We reported this case with a brief review of literature.

• Journal of Genetic Medicine
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• v.9 no.2
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• pp.84-88
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• 2012

Purpose: Neurofibromatosis type 1 (NF1), which is caused by mutations of the NF1 gene, is the most frequent single gene disorder to affect the nervous system. Unidentified bright objects (UBOs) are commonly observed on brain magnetic resonance imaging (MRI) in patients with NF1. However, their clinical and pathologic significance is not well understood. The purpose of this study was to investigate the correlation between UBOs and cerebral glucose metabolism measured by $^{18}F$-2-Fluoro-2-deoxy-D-glucose ($^{18}F$-FDG) positron emission tomography (PET) in Korean patients with NF1. Materials and Methods: Medical records of 75 patients (34 males and 41 females) with NF1 who underwent brain MRI and PET between 2005 and 2011 were evaluated retrospectively. Clinical data including demographics, neurological symptoms, and brain MRI and PET findings, were reviewed. Results: UBOs were detected in the brain MRI scans of 31 patients (41%). The region most frequently affected by UBOs was the basal ganglia. The most frequent brain PET finding was thalamic glucose hypometabolism (45/75, 60%). Of the 31 patients with UBOs, 26 had thalamic glucose hypometabolism on brain PET, but the other 5 had normal brain PET findings. Conversely, of the 45 patients with thalamic glucose hypometabolism on brain PET, 26 showed UBOs on their brain MRI scans, but 19 had normal findings on brain MRI scans. Conclusion: UBOs on brain MRI scans and thalamic glucose hypometabolism on PET appear to be 2 distinctive features of NF1 rather than correlated symptoms. Because the clinical significance of these abnormal imaging findings remains unclear, a longitudinal follow-up study of changes in clinical manifestations and imaging findings is necessary.

• Journal of the Korean Society of Radiology
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• v.82 no.2
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• pp.417-422
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• 2021

Neurofibromatosis type 1 (NF1) is a rare neuroectodermal disease that is associated with an increased risk of malignancy. Here, we report a rare case of bilateral breast cancer in a 49-year-old woman with NF1 that presented as a microlobulated oval hypoechoic mass and a complex cystic solid mass on sonography. She underwent bilateral mastectomy. The masses were diagnosed as invasive ductal carcinoma, ductal carcinoma in situ, and a malignant peripheral nerve sheath tumor. We describe the imaging findings, including ultrasonography, CT, and ¹⁸F-fluorodeoxyglucose PET.

• Molecules and Cells
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• v.20 no.2
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• pp.196-200
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• 2005

The neurofibromatosis type2 (NF2) tumor suppressor gene product, merlin, is structurally related to the ezrin-radixin-moesin (ERM) family of proteins that anchor the actin cytoskeleton to specific membrane proteins and participate in cell signaling. However, the basis of the tumor suppressing activity of merlin is not well understood. Previously, we identified a role of merlin as an inhibitor of the Ras-ERK signaling pathway. Recent studies have suggested that phosphorylation of merlin, as of other ERM proteins, may regulate its function. To determine whether phosphorylation of merlin affects its suppression of Ras-ERK signaling, we generated plasmids expressing full-length merlin with substitutions of serine 518, a potential phosphorylation site. A substitution that mimics constitutive phosphorylation (S518D) abrogated the ability of merlin to suppress effects of the Ras-ERK signaling pathway such as Ras-induced SRE transactivation, Elk-mediated SRE transactivation, Ras-induced ERK phosphorylation and Ras-induced focus formation. On the other hand, an S518A mutant, which mimics nonphosphorylated merlin, acted like wild type merlin. These observations show that mimicking merlin phosphorylation impairs not only growth suppression by merlin but also its inhibitory action on the Ras-ERK signaling pathway.

• Journal of Korean Neurosurgical Society
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• v.63 no.6
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• pp.738-746
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• 2020

Objectives : The purpose of this study was to evaluate surgical outcomes and complications of spinal deformity associated with neurofibromatosis type-1 (NF-1). Methods : From 2012 to 2018, patients suffering from spinal deformity associated with NF-1 who underwent surgical correction were identified. Demographic data and radiographic measures were retrospectively reviewed. Pre- and postoperative whole spine radiograph images were used to determine both coronal and sagittal Cobb angles. All of patients underwent 3-dimentional computed tomographic scan and magnetic resonance imaging scan to confirm dystrophic features. For evaluation of clinical outcomes, we surveyed the pre- and postoperative scoliosis research society-22r (SRS-22r) score. Results : Seven patients with spinal deformity associated with NF-1 were enrolled in this study. The mean age of patients was 29.5±1.2 years old. The mean follow-up period was 2.8±1.4 years. The apex of the deformity was located in cervicothoracic (n=1), thoracic (n=4), and lumbar region (n=2). Most patients have poor bone quality and decreased bone mineral density with average T-score of -3.5±1.0. All patients underwent surgical correction via posterior approach. The pre- and postoperative mean coronal and sagittal Cobb angle was 61.6±22.6° and 34.6±38.1°, 56.8±18.5° and 40.2±9.1°, respectively. Mean correction rate of coronal and sagittal angle was 44.7% and 23.1%. Ultimate follow-up SRS-22r score (average score, 3.9±0.4) improved comparing to preoperative score (average score, 3.3±0.9). Only one patient received revision surgery due to rod fracture. No serious complication occurred, such as neurological deficit, and viscerovascular injury. Conclusion : The surgical correction of patients having spinal deformity associated with NF-1 is challenging, however the radiographic and clinical outcomes are satisfactory. The all posterior approach can be a safe and effective surgical option for patients having dystrophic curves associated with NF-1.

• Clinical and Experimental Pediatrics
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• v.49 no.2
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• pp.203-207
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• 2006

Neurofibromatosis type 1 (von Recklinghausen disease, NF1) involves the central and peripheral nervous systems as well as the skin, bone, endocrine, gastrointestinal and vascular systems. The gastrointestinal neurofibroma associated with NF1 has been infrequently reported. We report our experience with a 15-year-old boy who had a gastric plexiform neurofibroma with upper gastrointestinal bleeding and underwent a tumorectomy because of massive upper gastrointestinal bleeding. We conclude that gastrointestinal bleeding and anemia in the setting of NF1 mandates complete endoscopic examination of the digestive tract to rule out neurofibromas. Surgical resection is the standard treatment.

• The Journal of the Korean bone and joint tumor society
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• v.6 no.2
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• pp.77-81
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• 2000

Malignant peripheral nerve sheath tumors(MPNSTs) are uncommon sarcomas that mostly arise in the soft tissue. They can develop from the pre-existing neurofibromas or schwannomas, or denovo from the peripheral nerves, or they can occur following the radiation therapy. We report a case of MPNST that developed in the sciatic nerve of the patient with neurofibromatosis type-1(NF-1). The patient was a 39-year-old man with the history of NF-1, who's main symptom was a rapidly enlarging painful mass in his posterior thigh. The well demarcated tumor, $6.5{\times}5{\times}4.5$cm in size, was composed of closely packed spindle cells. Since the patients with NF-1 have a high risk for developing a recurred MPNST, the importance of the clinical follow up is emphasized.

• Journal of Korean Neurosurgical Society
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• v.55 no.1
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• pp.43-47
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• 2014

Patients with neurofibromatosis 1 (NF1) are predisposed to develop central nervous system tumors, due to the loss of neurofibromin, an inactivator of proto-oncogene Ras. However, to our knowledge, only three cases of ependymomas with NF1 have been reported in the literature. The authors present a case of NF1 patient with a spinal cord ependymoma. She was referred for about half a year history of increasing numbness that progressed from her fingers to her entire body above the bellybutton. Magnetic resonance imaging revealed a relative-demarcated, heterogeneously enhanced mass lesion accompanied by perifocal edema in C5-7 level, a left-sided T11 spinous process heterogeneously enhanced mass in soft tissue, intervertebral disk hernia in L2-5 level, and widespread punctum enhancing lesion in her scalp and in T11-L5 level. The patient underwent C5-7 laminectomies and total excision of the tumor under operative microscope, and intraoperative ultrasonography and physiological monitoring were used during the surgery. Histopathologically, her tumor was found to be a ependymoma without malignant features (grade II in the World Health Organization classification). Therefore, no adjuvant therapy was applied. Following the operation, the patient showed an uneventful clinical recovery with no evidence of tumor recurrence after one year of follow-up.

• Childhood Kidney Diseases
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• v.17 no.2
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• pp.143-148
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• 2013

Neurofibromatosis type 1 (NF-1) is an autosomal dominant neurocutaneous disorder, which can affect different organs or systems of the body, including the cardiovascular system. One of the more serious aspects of the disease relates to arterial involvement. In particular, renal artery stenosis is one of the most common vascular abnormalities in patients with NF-1, and the manifestations vary, ranging from no symptoms to end-stage renal failure. Treatment usually consists of antihypertensive drugs, percutaneous transluminal angioplasty, or surgery. Other causes of hypertension should be ruled out and the patient followed up for close monitoring and proper management. We report a case of bilateral renal artery stenosis and hypertension in a patient with moyamoya disease associated with neurofibromatosis type 1. This report discusses the literature available on the current subject, its clinical features, diagnosis, and treatment.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.24 no.1
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• pp.181-188
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• 1994

Neurofibromatosis, or Von Recklinghausen's disease is inhereted as an autosomal dominent neurocutaneous systemic disease. It is characterized by multiple Cafe-au-lait spots, generlaized cutaneous neurofibromas. It affects one in 3000 births. We observed the clinical, radiologic and histopathologic findings of 3 cases of neurofibromatosis and obtained following results. 1. All patients had multiple Cafe-au-lait spots and neufibromas. 2. Two patients had radiographic changes of pressive erosion and mesodermal dysplasia. 3. Two patients had plexiform neurofibromas and 1 patient had diffuse neurofibromas. Conclusively, we classified these 3 cases as NF-I.