Neurofibromatosis type 1 (NF1) associated with tumor of the corpus callosum.

INTRODUCTION: Neurofibromatosis type 1 (NF1), one of the most common neurocutaneous disorders, is a multisystemic disease associated with tumors in any organ of the body, especially in the central nervous system and also the peripheral nervous system. Pilocytic astrocytomas have been described in almost all intracranial regions in patients with NF1. However, only a few patients with NF1 and tumor of the corpus callosum have been reported to date. MATERIAL AND METHODS: An 11-year-old white Spanish boy was evaluated due to a family history of NF1 and low performance test scores in school. He was studied from the neurological and intellectual level points of view. RESULTS: Magnetic resonance (MR) study revealed a tumor in the anterior-middle portion of the corpus callosum and a Wechsler Intelligence Scale for Children-Revised showed verbal IQ of 92, a performance IQ of 108, and a total IQ of 100. In addition, he showed attention deficit and hyperactivity disorder. CONCLUSIONS: Tumors of corpus callosum in patients with NF1 are very uncommon. The patient presented in this paper consulted due to family history of NF1, progressive hyperactivity, and below average school performance. The MR study showed tumor in the corpus callosum. Tumor histology was not investigated.

Hyperglycosylation and reduced GABA currents of mutated GABRB3 polypeptide in remitting childhood absence epilepsy.

Childhood absence epilepsy (CAE) accounts for 10% to 12% of epilepsy in children under 16 years of age. We screened for mutations in the GABA(A) receptor (GABAR) beta 3 subunit gene (GABRB3) in 48 probands and families with remitting CAE. We found that four out of 48 families (8%) had mutations in GABRB3. One heterozygous missense mutation (P11S) in exon 1a segregated with four CAE-affected persons in one multiplex, two-generation Mexican family. P11S was also found in a singleton from Mexico. Another heterozygous missense mutation (S15F) was present in a singleton from Honduras. An exon 2 heterozygous missense mutation (G32R) was present in two CAE-affected persons and two persons affected with EEG-recorded spike and/or sharp wave in a two-generation Honduran family. All mutations were absent in 630 controls. We studied functions and possible pathogenicity by expressing mutations in HeLa cells with the use of Western blots and an in vitro translation and translocation system. Expression levels did not differ from those of controls, but all mutations showed hyperglycosylation in the in vitro translation and translocation system with canine microsomes. Functional analysis of human GABA(A) receptors (alpha 1 beta 3-v2 gamma 2S, alpha 1 beta 3-v2[P11S]gamma 2S, alpha 1 beta 3-v2[S15F]gamma 2S, and alpha 1 beta 3-v2[G32R]gamma 2S) transiently expressed in HEK293T cells with the use of rapid agonist application showed that each amino acid transversion in the beta 3-v2 subunit (P11S, S15F, and G32R) reduced GABA-evoked current density from whole cells. Mutated beta 3 subunit protein could thus cause absence seizures through a gain in glycosylation of mutated exon 1a and exon 2, affecting maturation and trafficking of GABAR from endoplasmic reticulum to cell surface and resulting in reduced GABA-evoked currents.

Neurosurgical treatment of tuberous sclerosis complex lesions.

BACKGROUND: Tuberous sclerosis complex (TSC) is an autosomal dominantly inherited syndrome. Renal disease is the main cause of death. Brain disorders are the origin of more frequent and severe problems, such as tumors, epilepsy, and mental retardation. Participation of neurosurgeons in the study and especially in the treatment of TSC patients is often required. MATERIALS AND METHODS: Two types of pathological conditions mainly require neurosurgical interventions in TSC: subependymal giant cell astrocytomas (SGCA) and cortical tubers. SGCA are located in the cerebral region close to the foramina of Monroe, uni- or bilaterally, and originate in hamartomas that can grow slowly as well as rapidly, even suddenly, especially in cases with intratumoral cyst, causing increased intracranial pressure (ICP) with severe risk for visual loss and life. Neurosurgeons have to participate in the follow-up of the patients as soon as the risk of ICP exists to remove the tumor when the criteria of SGCA growth are present. The other intracranial lesions that require neurosurgical intervention by are the cortical tubers. CONCLUSION: These dysplastic lesions are associated with TSC in almost the 100% of affected persons and are the cause of epilepsy in most patients. The seizures can be resistant to antiepileptic medication in many cases in which a tuber is identified as the origin of the focal seizures after functional studies, such as EEG, MR, PET, etc. In these cases, only surgical removal of the tuber and the perituberal epileptogenic foci can cure the epilepsy. Large tubers are more epileptogenic than smaller ones.

Pascual-Castroviejo type II syndrome (P-CIIS). Importance of the presence of persistent embryonic arteries.

INTRODUCTION: Cutaneous hemangioma and vascular malformation are two vascular abnormalities frequently associated with absence or hypoplasia of one or both carotid and/or vertebral arteries, presence of persistent embryonic arteries, especially the trigeminal, cerebellar malformations, and coarctation of the aortic arch and/or congenital cardiopathy. This disease is known as Pascual-Castroviejo type II syndrome (P-CIIS) and by the acronym PHACE. MATERIAL AND METHODS: Three patients (two females and one male) with facial hemangioma are studied during the first years of age by magnetic resonance angiography (MRA) and their vascular evolution to adult age followed through several MRA controls. RESULTS: All the three patients showed persistence of the trigeminal artery associated to other intra- and extracranial vascular abnormalities of type hemangioma or hemangiomatous arteries that presented progressive involution with decreased arterial caliber without appearing cerebrovascular stroke or hypoxic zones because, at the same time, collateral vascularization appeared through connections between the embryonic arteries and the peripheral branches of the internal carotids or connections between branches of the external and internal carotids. Only one patient had obstruction of a branch of the left middle cerebral artery after 3 days, with gastroenteritis with elevated fever at 17 months of life that caused parenchymal infarct in the left cerebral region supplied by the obstructed artery. CONCLUSIONS: The presence of embryonic arteries, especially the trigeminal, and connections between branches of the internal and external carotids, mainly through the internal maxillary and ophthalmic arteries, ensure the cerebral supply in the P-CIIS despite the progressive involvement of the cerebral arteries.

An overview of L-2-hydroxyglutarate dehydrogenase gene (L2HGDH) variants: a genotype-phenotype study.

L-2-Hydroxyglutaric aciduria (L2HGA) is a rare, neurometabolic disorder with an autosomal recessive mode of inheritance. Affected individuals only have neurological manifestations, including psychomotor retardation, cerebellar ataxia, and more variably macrocephaly, or epilepsy. The diagnosis of L2HGA can be made based on magnetic resonance imaging (MRI), biochemical analysis, and mutational analysis of L2HGDH. About 200 patients with elevated concentrations of 2-hydroxyglutarate (2HG) in the urine were referred for chiral determination of 2HG and L2HGDH mutational analysis. All patients with increased L2HG (n=106; 83 families) were included. Clinical information on 61 patients was obtained via questionnaires. In 82 families the mutations were detected by direct sequence analysis and/or multiplex ligation dependent probe amplification (MLPA), including one case where MLPA was essential to detect the second allele. In another case RT-PCR followed by deep intronic sequencing was needed to detect the mutation. Thirty-five novel mutations as well as 35 reported mutations and 14 nondisease-related variants are reviewed and included in a novel Leiden Open source Variation Database (LOVD) for L2HGDH variants (http://www.LOVD.nl/L2HGDH). Every user can access the database and submit variants/patients. Furthermore, we report on the phenotype, including neurological manifestations and urinary levels of L2HG, and we evaluate the phenotype-genotype relationship.

Posterior fossa tumors in children with neurofibromatosis type 1 (NF1).

BACKGROUND: Tumours of the posterior fossa associated with neurofibromatosis type 1 (NF1) are very infrequent. Series studying this association are seldom reported. PERSONAL EXPERIENCE: In a series of 600 NF1 patients studied during 39 years (1965-2004) only five (0.83%) had posterior fossa tumours. They were studied clinically, radiologically by computerized tomography (CT) or magnetic resonance (MR) and histologically. Four of them had astrocytomas but only in one case was the tumour primarily cerebellar while the tumour was primarily of the brain stem with invasion of the adjacent regions of one or both cerebellar hemispheres in three patients. The fifth tumour was a medulloblastoma that had a survival of 3 years following treatment. The patient with primary cerebellar astrocytoma is apparently cured 7 years after the removal of the tumour. The patients with the brain stem tumours extending to the cerebellum, showed a chronic slowly progressive cerebellar disease, but remain alive at age of more than 20 years (one was lost to follow-up). DISCUSSION AND CONCLUSION: The aim of this study was to present five children (one male and four females) less than 16 years of age when they were initially seen in our service, who had NF1 associates with posterior fossa tumours. This location is very uncommon in patients with NF1, in contrast with those located in other regions, such as pathway optic tumours and brain stem tumours. Most of these tumours are histologically benign (low grade astrocytomas). Only one patient in this series had a medulloblastoma, an exceptionally rare tumour seldom reported in patients with NF1.

Sturge-Weber syndrome: study of 55 patients.

PURPOSE: To review the clinical and neuroimaging features of a large series of patients with Sturge-Weber syndrome (SWS) seen over a 40-year period. METHODS: Fifty-five patients with SWS (30 males and 25 females), were studied between 1965 and 2004. Results of neurological and ophthalmological examinations, electroencephalographic, and neuroimaging studies were reviewed. All patients were seen by one of the authors (I. P-C). RESULTS: Epilepsy, hemiparesis, mental retardation and ocular problems were the most frequent and severe features of patients with Sturge-Weber syndrome in this series. The facial nevus flammeus was unilateral in 35 (63.5%) patients, bilateral in 17 (31%) and absent in 3 (5.5%) of the patients with leptomeningeal angiomas. Seven (41%) of the 17 patients with bilateral nevus flammeus had unilateral leptomeningeal angiomas. Seizures occurred in 47 patients (85.5%). Complete seizure control was obtained in 20 patients (42.5%), but in 2 of these 20 patients seizures were controlled only after lobectomy. All patients with unilateral or bilateral upper eyelid nevus flammeus had ipsilateral, unilateral or bilateral choroid-retinal angiomas. Only 20 (36%) of the 55 patients had low-normal or borderline intelligence (IQs < 70). No relationship was observed between the size of the facial nevus flammeus and the severity of the brain lesion. CONCLUSIONS: Epilepsy, hemiparesis, mental retardation and ocular problems were the most frequent and severe features of patients with Sturge-Weber syndrome in this series. Cerebral lesions followed a progressive course during early childhood, but not later. Early surgical treatment controlled the seizures but other neurological problems such as hemiparesis and intellectual deficits showed a less satisfactory response. Early onset of seizures and poor response to medical treatment, bilateral cerebral involvement and unilateral severe lesions were indicative of a poor prognosis. Limited intelligence and social skills, poor aesthetic appearance and seizures complicated the integration of SWS patients. These features must be addressed in order for the patients improve social interactions, obtain gainful employment and achieve a better quality of life.

Diplegia due to transcranial knife-blade injury in a 20-month-old child.

Transcranial stab wounds are uncommon among both adults and adolescents and rarely occur in children, particularly when caused by another child. A 20-month-old girl was injured by a 3-year-old cousin, who introduced a knife blade into the brain through the left parietal region. The trajectory of the wound penetrated at least 5 cm, crossed the falx cerebri, and involved both motor cortical areas. The clinical sequela was a severe symmetric spastic diplegia.

Cobb syndrome: case report.

We present a 7-year-old boy in whom cutaneous hemangioma and intramedullary and paraspinal arteriovenous malformations were associated. Magnetic resonance arteriography revealed the presence of the two arterovenous malformations, and the selective intercostal arteriography demonstrated that the intraspinal and paraspinal arteriovenous malformations were supplied by the same intercostal arteries. Rubbing the back was required to detect the cutaneous changes, which were only suspected by casual inspection.

Congenital vascular malformations in childhood.

Congenital vascular malformations are an important group of vascular anomalies that occur very early in the pregnancy. Most of these malformations occur between the third and the seventh weeks of the embryonic development. Malformations can affect the arteries, veins, capillaries, and venous sinuses, involving an isolated vessel or a part of the vascular system. There are malformations that affect the vessel size or course, and others that show pathology of the wall anatomy of the vessel. Magnetic resonance angiography (MRA) is improving the study conditions of this pathology. Treatment of most of the vascular malformations--some of them giving clinical symptoms during adulthood--still constitutes a challenge.

[Voluminous plexiform neurofibromas of the neck region in neurofibromatosis 1]. / Neurofibromas plexiformes voluminosos de cuello en la neurofibromatosis tipo 1.

AIM. To present the clinic, imaging and evolutive characteristics of a series of patients with neurofibromatosis 1 with voluminous plexiform neurofibromas in the neck (VPNFN) during childhood. PATIENTS AND METHODS. Nine patients (five females and four males) who were diagnosed as VPNFN at ages between 3 and 15 years. The VPNFN widespread to the posterior fossa or the upper thoracic region in some cases. The diagnosis was based on the clinical, imaging and histological findings. RESULTS. One of the tumors was intralaryngeal and caused respiratory difficulties. The other eight patients had the origin of the tumor in several spinal roots of one or both sides and could growth to the posterior fossa and to the upper thoracic region in some cases with displacement of the surrounding organs, especially in three patients, all girls, in whom the tumor reached a voluminous size on one side, that was observed only until 10 to 11 years when the growth ceased. CONCLUSIONS. The VPNFN are histologically benign tumors. Those located in the larynx must be removed because of the respiratory problems, but it is not necessary in cases with other locations despite the voluminous size that can reach in some patients with great displacement of the surrounding organs. The analysis of the results of our series may demonstrate that al least the extralaryngeal tumors only grow to 11-12 years of age. This possibility may make recommendable to retard the surgical treatment as much as possible in cases that it is not necessary.

TITLE: Neurofibromas plexiformes voluminosos de cuello en la neurofibromatosis tipo 1.Objetivo. Presentar las caracteristicas clinicas, de imagen y evolutivas de una serie de pacientes con neurofibromatosis tipo 1 que desarrollaron durante la infancia neurofibromas plexiformes voluminosos en el cuello (NFPVC). Pacientes y metodos. Nueve pacientes (cinco mujeres y cuatro varones) con edades entre 3 y 15 años en el momento del diagnostico de los tumores, que podian extenderse tambien a la fosa posterior y a la zona toracica superior. El diagnostico estuvo basado fundamentalmente en la clinica, la imagen y la histologia. Resultados. Un tumor era intralaringeo y causaba problemas respiratorios. Los otros ocho casos tenian su origen en varias raices espinales de uno o de ambos lados y podian crecer tambien hacia el interior de la fosa posterior y de la region toracica en algunos pacientes, y desplazaban a las estructuras anatomicas vecinas, especialmente en tres casos, todos niñas, en las que el tumor crecio hasta alcanzar gran volumen, especialmente por un lado, parandose el crecimiento entre los 11 y 12 años y no volviendo a crecer mas tarde. Conclusiones. Los NFPVC son tumores histologicamente benignos. La extirpacion es necesaria cuando estan localizados en la laringe por los problemas respiratorios que causan, pero no en los de las otras regiones, pese a que el voluminoso tamaño que alcanzan en algunos casos puede causar exagerados desplazamientos de las estructuras vecinas. El estudio de nuestra serie parece indicar que al menos los tumores extralaringeos solo crecen hasta los 11-12 años. Puede ser recomendable retrasar la cirugia tanto como sea posible si no existe sintomatologia aguda que la haga necesaria.

[Corpus callosum tumor as the presenting symptom of neurofibromatosis type 1 in a patient and literature review]. / Tumor del cuerpo calloso como presentación de neurofibromatosis tipo 1 en un paciente y revisión de la bibliografía.

INTRODUCTION: Neurofibromatosis type 1 (NF1) is one of the most frequent neurocutaneous syndromes. NF1 can be associated with intracranial tumors in any location, but only rarely in the corpus callosum. AIMS: To describe a case of NF1 presenting as a tumor of the corpus callosum and to carry out a review of the incidence of the tumors of corpus callosum in our series and in the literature. CASE REPORT: We present a child who was studied since 3 years of age because of complete NF1 clinical diagnostic criteria (without genetic study). He was studied by MR and magnetic resonance spectroscopy (MRS). MR study showed neurofibromatosis bright objects distributed over several regions of the cerebral hemispheres and cerebellum, a possible brain stem tumor (bulbar zone) and the splenium of the corpus callosum. The MRS of the brain stem tumor showed changes consistent with a low grade glial tumor. The patient was followed until 19-years of age without demonstrating any changes in the clinical features or the tumor size in both locations Only six cases of corpus callosum tumor in patients with NF1 have been published to date. CONCLUSIONS: We present a new case with tumor of the corpus callosum and NF1. The imaging characteristics and the clinical course were in favour of the benign nature of this type of tumor.

Bilateral spinal neurofibromas in patients with neurofibromatosis 1.

Neurofibromatosis 1 (NF1) is a neurocutaneous syndrome that can be inherited as autosomal dominant or may appear due to a de novo mutation. We present 8 patients (5 M and 3 F) with sporadic or non-familial spinal neurofibromatosis 1 (non-FSNF1) associated with bilateral spinal neurofibromas involving all of the paraspinal nerves. To our knowledge, this is the first series of such association described in the literature. Their ages ranged from 6 months to 20 years (average 9.8 years) at the time of radiological diagnosis. This presentation appears to be earlier than in familial spinal neurofibromas in NF1 (FSNF1). Predisposition to malignancy probably is greater in the non-FSNF1 type. MRI studies were performed routinely in all patients with NF1 and these were complemented with MRI enhanced with gadolinium and repeated at different ages in cases with paraspinal tumors. Coronal views provided the best evidence for the presence of neurofibromas in every spinal nerve. The size of the tumors and the clinical complications increased with advancing age in most patients. Giant plexiform tumors were often seen in the cervico-thoracic region. Malignant peripheral nerve sheath tumors (MPNST) were found in one patient with a sciatic tumor and another patient died suddenly at home without necropsy or pathological study. Voluminous paraspinal neurofibromas can be at risk for malignancy. More frequent neuroimaging studies may be necessary for an earlier detection. Early surgical treatment to anticipate the occurrence of MPNST during surveillance could be an option. Bilateral spinal neurofibromas are found in both patients who inherited the NF1 and in those due to de novo mutations.

Treating spastic equinus foot from cerebral palsy with botulinum toxin type A: what factors influence the results?: an analysis of 189 consecutive cases.

OBJECTIVE: The aim of this study was to determine the variables that improve spastic equinus foot caused by cerebral palsy when treated with botulinum toxin type A. DESIGN: We reviewed all patients treated for spastic equinus foot using botulinum toxin type A (Botox) in the triceps suralis during a 3 1/2-yr period and analyzed the results after the first injection. There were 117 patients (72 diplegic and 45 hemiplegic patients) and a total of 189 triceps suralis treated. Variables analyzed included age, total dose per session, total dose per kilogram for each session, total dose per triceps, triceps dose per kilogram, type of cerebral palsy, cognitive level, botulinum toxin dilution, and physiotherapy. Assessments of efficacy were done using a Global Assessment Scale rated independently by parents, therapists, and a neurologist; the Modified Ashworth Scale; and the Modified Physician Rating Koman scale. RESULTS: Improvement was observed in all scales (P < 0.001). The change of foot position during walking was the best parameter for measuring improvement. There was correlation between the grade of improvement and the dose per kilogram for each triceps suralis (P < 0.001). Patient age was inversely correlated with improvement (P = 0.043). Diplegic and hemiplegic patients improved similarly, but the hemiplegic patients required higher doses for each muscle (P < 0.001). The most effective dose for diplegic patients was 3-4 IU/kg for each triceps, compared with 4-6 IU/kg for hemiplegic patients. Different dilutions of Botox (100, 50, and 40 U/ml) resulted in similar outcomes. No better results were achieved when 2-3 sessions/wk of physiotherapy was added to a daily program of exercises at home to enhance foot dorsiflexion. CONCLUSIONS: The dose per kilogram of Botox injected into triceps suralis and the patient age influence the results. The most effective dose is different between diplegic and hemiplegic patients. The concentration of botulinum toxin type A does not play a significant role in the outcome.

[Spontaneous involution of frontal tumors in a patient with neurofibromatosis type 1]. / Involución espontánea de tumores frontales en un paciente con neurofibromatosis tipo 1.

AIM: To present a patient with neurofibromatosis type 1 (NF1) who had cerebral tumors (in a non-optic pathway location) that regressed spontaneously. CASE REPORT: A girl with NF1 and cerebral tumors, probably astrocytomas, with similar neuroimaging characteristics, was studied by magnetic resonance (MR) and MR spectroscopy between 29 months and 6- years of age. The frontal tumors (one on each hemisphere) did not change size in the MR studies done during the first three and a half years of life, but, at six years, the right frontal lobe tumor had apparently disappeared and the left frontal lobe tumor had decreased in a 90% of its original size. During the first three and half years of life, MR images did not demonstrate any optic tumor. However, such a tumor appeared well developed when the MR study was performed at six years of age. CONCLUSION: Involution of cerebral tumors associated with NF1, unrelated to optic pathway, is rare, but has been observed in some patients. Optic pathway tumors can develop in patients with NF1 between three and six years of age.

Major and minor arterial malformations in patients with cutaneous vascular abnormalities.

The association of persistent embryonic arteries and the absence of 1 carotid or vertebral arteries with facial or neck hemangioma or vascular malformation have been frequently described. The abnormalities can involve major or minor vessels. Of 22 patients of our series with this neurocutaneous syndrome, 20 had the origin of both anterior cerebral arteries from the same internal carotid artery. Thirteen patients showed absence or hypoplasia of 1 carotid artery and 10 of 1 vertebral artery; 10 showed persistence of the trigeminal artery; 3 had persistent proatlantal artery; 6 showed the absence of the posterior communicating artery; and 4 had hypoplastic posterior cerebral artery. Other less frequent abnormalities were found in 7 patients. Intellectual level of most patients was either borderline or below normal. Abnormalities in the vascularization and perfusion of the frontal lobes may contribute to the borderline or lower mental level of these patients.

[Cerebral hemisphere tumours in neurofibromatosis type 1 during childhood]. / Tumores de los hemisferios cerebrales en la neurofibromatosis tipo 1 durante la infancia.

AIM: To present seven tumors of the cerebral hemispheres in 6 children with neurofibromatosis type 1 (NF1). PATIENTS AND METHODS: Six patients (three males and three females) of 600 cases of a series with NF1 showed features of cerebral hemispheres tumor (seizures, headache and hemiparesis). They were studied neurologically, by EEG and by image (MR and/or spectroscopic-MR) because of these features or simply because having NF1. RESULTS: All the patients had the two diagnostic criteria of the NF1. Six patients had seven tumors (it was because one of them had one tumor in every frontal lobe, both with the same image characteristics), but they did not were removed and they were not studied histologically. The histological study was made to the other five patients and showed that the histological nature corresponded to pilocytic astrocytoma in one patient, neuroepitelial dysembryoplastic tumor in one, polymorphe xanthoastrocytoma in one, neuroectodermic hamartoma in one, and inflammatory chronic non-granulomatose lesion in one. CONCLUSION: The prevalence of the tumors in the cerebral hemispheres is very low (1%) in the patients with NF1. The tumors commonly are histologically benign, and they can be found in peripheral or deep region of the cerebral hemispheres. Identity of the tumors by MR study commonly is easy and the treatment is surgical in most cases. However, urgent treatment very seldom is necessary in these tumors, and most frequently is possible to take the attitude of 'wait and see' before to decide the definite treatment.

Safety of botulinum toxin type A in children younger than 2 years.

BACKGROUND: Botulinum toxin type A (BoNT-A) has been used in many indications and is licensed for the treatment of spasticity in children older than 2 years. However, there are few reports of BoNT-A treatment in patients younger than 2 years of age. AIMS: To review retrospectively the safety data from all infants treated with botulinum toxin type A (BoNT-A) before 2 years of age in a paediatric neurology unit. METHODS: There were 74 infants: 28 received the first dose before 1 year of age, and 46 between the ages of 1 and 2 years. RESULTS: In the first year of life, the most frequent indication was obstetric brachial palsy (OBP) (71.4% of cases) and in the second year, cerebral palsy (CP) (73.9%). Both Botox and Dysport, the two commercially-available BoNT-A products in Spain, were used. The average starting dose by session was 6.55 U/kg body weight Botox in infants in their first year of life, and 8.4 U/kg body weight Botox and 21.1 U/kg body weight Dysport in the second year of life. Only 3.6% of cases treated in the first year and 6.5% of those treated in the second experienced adverse events (AEs), which consisted of mild weakness or tiredness lasting 1-4 days. CONCLUSIONS: BoNT-A has a good safety profile in infants younger than 2 years old. AEs are similar to those found in older children.

Neurofibromatosis type 1 with external genitalia involvement presentation of 4 patients.

Genitourinary neurofibromas with clitoral involvement in neurofibromatosis type 1 are rare, and even more infrequent are the neurofibromas involving genitalia in males. The most frequent presenting sign of neurofibroma in females is clitoromegaly with pseudopenis, and enlarged penis is the most common sign in males. Labium majus neurofibroma not associated with clitoral involvement is extremely rare. Magnetic resonance imaging demonstration of the neurofibromas has seldom been reported. We report 4 children, 3 girls and 1 boy, with plexiform neurofibromas involving the external genitalia. Three of the 4 patients had histologic confirmation of neurofibroma. Two girls with clitoral hypertrophy had a neurofibroma that infiltrated the clitoris and extended unilaterally to the lower bladder wall. One girl had a plexiform neurofibroma that affected a labium. One boy with asymmetric penile hypertrophy since 2 years of age and ipsilateral gluteal hypertrophy had plexiform neurofibromas that extended between the left lumbogluteal and penile regions, infiltrating the left rectum wall and bladder with compression of both structures, the left prostate, and the left half of the cavernous corpi with hypertrophy of this part and asymmetry of the penis. Magnetic resonance imaging demonstrated in all patients that external genitalia and plexiform neurofibroma formed images of nondetachable structures. However, hermaphroditism was discarded by chromosomal study in all 3 girls before ratifying the diagnosis of external genitalia neurofibroma.