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41.
As an initial manifestation of neurofibromatosis type 1, isolated neurofibroma of the urinary bladder occurs only rarely in the first 2 decades of life. We report a case of a 6-year-old African-American girl who presented in this manner and was found to have a plexiform neurofibroma as well as diffuse ganglioneuromatosis of the urinary bladder. We describe the clinical presentation, diagnostic procedures, and pathologic features encountered. In addition, we review the literature with respect to etiology, current treatment strategies, and the issue of surveillance for this complex lesion occurring in the pediatric population. Neurofibroma of the bladder should be considered in the differential diagnosis of painless hematuria in childhood. Its presentation in such patients warrants a complete evaluation to establish the diagnosis of neurofibromatosis type 1 and begin long-term surveillance for its associated manifestations. At present, there are no established criteria for the treatment of this rare lesion.  相似文献   
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43.
Malignant peripheral nerve sheath tumors (MPNSTs) are uncommon soft tissue tumors. In children with neurofibromatosis 1 (NF1), a MPNST often arises in a pre-existing neurofibroma, or may represent an initial manifestation without other obvious stigmata of the disease. The development of MPNSTs may be associated with instability of the p53 tumor suppressor gene since it is the most frequent genetic abnormality in soft tissue sarcomas. To assess the presence of p53 accumulation in MPNSTs and its correlation with clinical and pathologic features, we studied 12 neurofibromas (NFs), including 4 tumors with cellular features (one congenital) and 10 MPNSTs. Six MPNSTs were associated with NF1, all of which developed within a plexiform neurofibroma. Cell proliferation evaluated with an antibody to Ki-67 and nuclear p53 staining were both detected by immunohistochemistry. We found p53 positivity in 60% of MPNSTs. All NFs except the congenital tumor were p53 immunonegative (P < 0.01). Rare p53-positive nuclei were detected in the transitional zone in two of six MPNSTs arising in plexiform NFs. Ki-67 distinguished the NFs from MPNSTs (P < 0.005). Half of the NF1 patients with p53-positive MPNSTs developed recurrence or metastases or developed a second malignancy within 2 years of diagnosis, whereas patients with p53-positive sporadic MPNSTs were free of disease 1 to 7 years later. We found p53 accumulation more frequently in NF1-associated MPNSTs. p53 mutations may be an additional biologic factor to account for the poor prognosis in these tumors. Received May 11, 1998; accepted August 31, 1998.  相似文献   
44.
患者,男,22岁。脱发1年余,头皮棕褐色肿物6个月。病理可见毛囊微小化,真皮下部大量细长梭形瘤细胞,波浪状排列。S-100多克隆(+),SOX-10(+),MelanA(+),Vimentin-10(+)。诊断为头皮局限性神经纤维瘤。后行手术治疗,随访中。  相似文献   
45.
Individuals with neurofibromatosis 1 (NF1) develop both benign and malignant tumors at an increased frequency. One of the most common benign tumors in NF1 is the plexiform neurofibroma. These tumors cause significant morbidity and mortality on account of their propensity to grow and affect adjacent normal tissues. To determine the clinical profile of plexiform neurofibromas in NF1, we conducted a retrospective review of 68 NF1 patients with plexiform neurofibroma. In our series, 44% of tumors were detected by 5 years of age and most were located in the trunk and extremities. Only two patients developed malignant peripheral nerve sheath tumors in their preexisting plexiform neurofibromas. Lastly, we demonstrate that there were no specific clinical features of NF1 associated with the presence of plexiform neurofibroma. These results underscore the importance of careful serial examinations in the evaluation of patients with NF1. Am. J. Med. Genet. 92:132–135, 2000. © 2000 Wiley‐Liss, Inc.  相似文献   
46.
Thoracic tumors have been infrequently reported as a complication of neurofibromatosis-1 (NF1). To determine the prevalence and clinical features of thoracic tumors seen in children with NF1, we reviewed medical records and imaging studies for a group of 260 pediatric patients with NF1 followed in a multidisciplinary NF Center. Extrapleural thoracic tumors were seen in nine patients with NF1, corresponding to a prevalence of 3.5% in this hospital-based series of patients. Pathological studies of the tumors demonstrated plexiform neurofibroma in four cases and neurofibrosarcoma in one case. The remaining four cases were suspected to be plexiform neurofibroma based on clinical features but have not been confirmed histologically. Three patients presented with symptoms of chest pain, syncope, or wheezing; six patients were asymptomatic at the time of diagnosis of the tumors. Physical findings frequently found in patients with thoracic tumors were scoliosis (especially focal scoliosis) and visible plexiform neurofibromas of the neck. We conclude that NF1 patients presenting with any of these signs and symptoms should be screened for thoracic tumors with chest X-ray and magnetic resonance imaging as needed. It is unknown whether screening asymptomatic NF1 patients with chest X-rays on a regular basis will result in an improved outcome. Am. J. Med. Genet. 74:533–537, 1997. © 1997 Wiley-Liss, Inc.  相似文献   
47.
48.
Neurofibromatosis type 1 (NF1) is a multisystem phakomatosis. The intrathoracic manifestations of NF1 are protean. We describe a rare case of a plexiform neurofibroma infiltrating the mediastinum and lungs with multiple endobronchial neurofibromata. To our knowledge, a mediastinal plexiform neurofibroma extending into the lungs on CT has not been reported.  相似文献   
49.
Kara M, Akyüz M, Y?lmaz A, Hatipo?lu C, Özçakar L. Peripheral nerve involvement in a neurofibromatosis type 2 patient with plexiform neurofibroma of the cauda equina: a sonographic vignette.We report a 20-year-old man with cauda equina syndrome and neurofibromatosis type 2. We discuss the role of sonographic and electromyographic evaluations in the management of our patient and suggest the use of sonographic imaging for visualization of peripheral nerve pathologic states, especially when involvement is widespread.  相似文献   
50.
Plexiform neurofibroma(PN)of the digestive tract is very rare and usually part of the generalized syndrome of neurofibromatosis type 1(von Recklinghausen disease).Solitary PN of the stomach is extremely rare and has not been reported in the literatures.Here we present a case of solitary PN of the stomach,which was not associated with von Recklinghausen disease.A38-year-old male presented abdominal pain and distention for 7 d.The patient underwent endoscopy of the upper gastrointestinal tract,which revealed a 3.5 cm protruding and cauliflower-shaped mass with a shallow1 cm central ulcer in the greater curvature of the stomach.The lesion was removed by laparoscopic surgery.Histological examination demonstrated characteristic histological findings of spindle-shaped cells.Immunohistochemical analysis showed that the tumor cells were positive for S-100 protein,but negative for CD34,KI-67,CD117,and actin.Based on histological findings,gastrointestinal stromal tumor could be excluded,and thus the case was confirmed as PN.We described the clinical features,physical examination,endoscopic findings,and histopathological examination of this case.  相似文献   
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