Neurofibromatosis type 1--an update and review for the primary pediatrician

Pheochromocytoma crisis in a patient with newly diagnosed neurofibromatosis type 1

Pheochromocytoma occasionally engenders catecholamine-induced hypertension crisis. Pheochromocytoma is clinically identified in 0.1%-5.7% of patients with neurofibromatosis type 1 (NF1), which is 10 times more frequently than in healthy individuals. This report describes a case of newly diagnosed NF1 presenting with pheochromocytoma crisis, with severe electrolyte depletion and deteriorating recurrent ventricular tachycardia storm. Characteristic skin lesions such as café-au-lait macules and neurofibromas contributed to the diagnosis of NF1 and pheochromocytoma. No recurrence of electrolyte depletion was found after the adrenalectomy. Primary care physicians must distinguish the characteristic skin lesions of NF1, such as café-au-lait macules and neurofibromas and recognise the risk for pheochromocytoma.

A resected case of liver metastases from extra-adrenal retroperitoneal paraganglioma with von Recklinghausen's disease 16 years after the initial surgery

The patient was a 46-year-old man who had undergone resection for a bulky retroperitoneal tumor 16 years previously during a follow-up for von Recklinghausen’s disease. Histopathological examination of the resected specimen showed that the tumor was an extra-adrenal paraganglioma. After the surgery, he had survived without any recurrence of the tumor. However, 16 years after the initial surgery, liver tumors were identified, and he was referred to our hospital for further investigation and treatment. Abdominal imaging modalities showed three masses in the left lateral segment of the liver. Fluorodeoxyglucose-positron emission tomography/computed tomography showed an abnormal uptake of fluorodeoxyglucose corresponding to the mass lesions. The patient was diagnosed with a metastatic paraganglioma based on histopathological examination of a liver mass biopsy. The patient underwent left lateral sectionectomy of the liver. Histopathological examination of the resected specimen revealed proliferating cells with basophilic cytoplasm and oval densely stained nuclei arranged in an alveolar pattern, which was similar to the findings of the initial resection specimen. Immunohistochemical staining was positive for synaptophysin and chromogranin A. Based on these findings, the resected tumors were histopathologically diagnosed with liver metastases from the retroperitoneal paraganglioma. We concluded that this is an extremely rare case of liver metastases occurring long after the initial resection of extra-adrenal peritoneal paraganglioma with von Recklinghausen’s disease.

Hyperactive RAS/PI3-K/MAPK Signaling Cascade in Migration and Adhesion of Nf1 Haploinsufficient Mesenchymal Stem/Progenitor Cells

Neurofibromatosis type 1 (NF1) is an autosomal dominant disease caused by mutations in the NF1 tumor suppressor gene, which affect approximately 1 out of 3000 individuals. Patients with NF1 suffer from a range of malignant and nonmalignant manifestations such as plexiform neurofibromas and skeletal abnormalities. We previously demonstrated that Nf1 haploinsufficiency in mesenchymal stem/progenitor cells (MSPCs) results in impaired osteoblastic differentiation, which may be associated with the skeletal manifestations in NF1 patients. Here we sought to further ascertain the role of Nf1 in modulating the migration and adhesion of MSPCs of the Nf1 haploinsufficient (Nf1^+/−) mice. Nf1^+/− MSPCs demonstrated increased nuclear-cytoplasmic ratio, increased migration, and increased actin polymerization as compared to wild-type (WT) MSPCs. Additionally, Nf1^+/− MSPCs were noted to have significantly enhanced cell adhesion to fibronectin with selective affinity for CH271 with an overexpression of its complimentary receptor, CD49e. Nf1^+/− MSPCs also showed hyperactivation of phosphoinositide 3-kinase (PI3-K) and mitogen activated protein kinase (MAPK) signaling pathways when compared to WT MSPCs, which were both significantly reduced in the presence of their pharmacologic inhibitors, LY294002 and PD0325901, respectively. Collectively, our study suggests that both PI3-K and MAPK signaling pathways play a significant role in enhanced migration and adhesion of Nf1 haploinsufficient MSPCs.

Frequency of choroidal abnormalities in pediatric patients with neurofibromatosis type 1

PURPOSE

To investigate the frequency of choroidal abnormalities in pediatric patients with neurofibromatosis type 1 detected by infrared reflectance imaging.

METHODS

The fundus of 38 eyes of 19 patients with neurofibromatosis type 1 was examined using infrared reflectance imaging with optical coherence tomography. Forty eyes of 20 age-matched controls were examined similarly. Each patient was evaluated for the presence and the number of choroidal abnormalities. The correlation between the total number of choroidal abnormalities and the patient's age was studied.

RESULTS

A total of 19 patients (11 females, 8 males) were included. The mean age of the neurofibromatosis group was 8.63 ± 3.15 years (range: 4 to 16 years) and that of the control group was 9.05 ± 3.27 years (range: 4 to 15 years). Choroidal nodules appearing as bright patchy nodules were detected in 15 (78.9%) of 19 patients with neurofibromatosis type 1 and 1 (5%) of 20 control subjects. In terms of the frequency of choroidal abnormalities, the difference was significant between the patients with neurofibromatosis type 1 and the controls (P < .001). There was a positive correlation between the number of choroidal abnormalities in both eyes and the patient's age (r = 0.701, P = .001).

CONCLUSIONS

Choroidal abnormalities are frequent in neurofibromatosis type 1. Choroidal abnormalities detected by infrared reflectance imaging with optical coherence tomography can be used to diagnose neurofibromatosis type 1.

Neurofibromatosis type 1 and the "elephant man's" disease: the confusion persists: an ethnographic study

BACKGROUND

In 1986, two Canadian geneticists had demonstrated that Joseph Merrick, better known as the Elephant Man, suffered from the Proteus syndrome and not from neurofibromatosis type 1 (NF1), as was alleged by dermatologist Parkes in 1909. Despite this and although the two diseases differ at several levels: prevalence, diagnostic criteria, clinical manifestations and transmission, the confusion between NF1 and the "elephant man's" disease continues in medical and social representations by current linguistic usage, and in some media reports. With this article, we want to 1) document the persistence and extent of this fallacy, 2) identify certain critical factors that contribute to its persistence, and 3) evaluate its impact on the health and well being of patients with NF1 and their family members.

METHODOLOGY

Participant observation in the course of an ethnographic study on intergenerational dialogue between individuals with neurofibromatosis and their parents - Analysis of the scientific literature and of pinpoint articles in the print and online news media.

FINDINGS

Our findings show that because physicians have little knowledge about NF1, several print and online news media and a lot of physicians continue to make the confusion between NF1 and the disease the "elephant man". This misconception contributes to misinformation about the disease, feeding prejudices against affected patients, exacerbating the negative impacts of the disease on their quality of life, their cognitive development, their reproductive choices, as well as depriving them of proper care and appropriate genetic counseling.

CONCLUSION

If family physicians and pediatricians were properly informed about the disease, they could refer their patients with NF1 to NF clinics and to specialists. Thus, patients and their family members would benefit from better-tailored clinical management of their cases, perhaps even optimal management. [corrected]

Phase I trial of pegylated interferon-alpha-2b in young patients with plexiform neurofibromas

OBJECTIVE

Interferon has antiproliferative and antiangiogenic properties. We sought to evaluate preliminary efficacy and determine the recommended phase II dose (RP2D) for pegylated interferon-α-2b (PI) in patients with unresectable progressive or symptomatic plexiform neurofibromas (PN).

METHODS

PI was administered weekly in cohorts of 3-6 patients during the dose-finding phase and continued for up to 2 years. Twelve patients were treated at the RP2D to further evaluate toxicity and activity.

RESULTS

Thirty patients (median age 9.3 years, range 1.9-34.7 years) were enrolled. No dose-limiting toxicity (DLT) was seen in patients treated at the 3 μg/kg dose level (DL) during the first 4 weeks. All 5 patients treated at the 4.5 μg/kg DL came off study or required dose reductions for behavioral toxicity or fatigue. Similar DLT on the 3 μg/kg DL became apparent over time. There was 1 DLT (myoclonus) in 12 patients enrolled at the 1.0 μg/kg DL. Eleven of 16 patients with pain showed improvement and 13 of 14 patients with a palpable mass had a decrease in size. Five of 17 patients (29%) who underwent volumetric analysis had a 15%-22% decrease in volume. Three of 4 patients with documented radiographic progression prior to enrollment showed stabilization or shrinkage.

CONCLUSIONS

The RP2D of PI for pediatric patients with PN is 1 μg/kg/wk. Clinical and radiographic improvement and cessation of growth can occur.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that pegylated interferon-α-2b in patients with unresectable, progressive, symptomatic, or life-threatening PNs results in radiographic reduction or stabilization of PN size.

Endoscopic excision of a supraorbital schwannoma

Patients with neurofibromatosis 1 frequently require multiple tumor excisions over the course of many years. Minimally invasive techniques of excision offer promise in reducing morbidity and scarring in a group of patients with well-circumscribed benign tumors in aesthetically sensitive areas. The safety and efficacy of endoscopic approaches to a variety of conditions affecting the craniofacial frontal region are well established. This report describes the endoscopic excision of a benign supraorbital nerve schwannoma in a 5-year-old girl.

Supernormal electro-oculograms in patients with neurofibromatosis type 1

Purpose

To asses the retinal pigment epithelium (RPE) function measured by EOG testing in patients with neurofibromatosis type 1 (NF-1). Our preliminary EOG results suggested dysfunction of the RPE in individuals with NF-1. In order to confirm our initial results we performed EOG examination on a larger group of NF-1 patients.

Patients

Studies were performed on 36 patients with clinically diagnosed NF-1 and compared to normal healthy controls.

Methods

Standard EOG recordings were performed in accordance with the International Society for Clinical Electrophysiology of Vision (ISCEV) standards.

Results

In NF-1 patients the Arden indexes of the EOG test were significantly higher primarily due to the lower values of dark troughs. Supernormal EOGs (exceeding the value of the mean + 2 SD from the control group) were present in 58% of NF-1 patients.

Conclusions

Dysfunction of the RPE is a characteristic feature of individuals with NF-1.

Is a plexiform neurofibroma pathognomonic of neurofibromatosis type I?

OBJECTIVES/HYPOTHESIS

Several prominent textbooks have claimed that a plexiform neurofibroma is pathognomonic for neurofibromatosis type I. This is not in agreement with the National Institutes of Health criteria, which require two signs to be present, one of which can be a plexiform neurofibroma. Is a plexiform neurofibroma pathognomonic for neurofibromatosis type I?

STUDY DESIGN

Retrospective chart review.

METHODS

Fifty-one patients with surgically resected plexiform neurofibromas between the years 1991 and 2001 were identified, and their charts reviewed. The presence and absence of any manifestation of neurofibromatosis type I as detailed in the National Institutes of Health criteria were recorded. The pathology database at the Hospital for Sick Children (HSC) was searched retrospectively.

RESULTS

Five of the 51 patients had a single solitary plexiform neurofibroma. They were followed at the neurofibromatosis clinic at the HSC with regular detailed examinations and no other stigmata were found.

CONCLUSION

Although plexiform neurofibromas are highly suggestive of neurofibromatosis type I, they are not pathognomonic as claimed.

Neurofibromatosis type I: clinical and imaging features of Von Recklinghausen's disease

OBJECTIVE

To discuss the case of a 45-year-old woman, with a prior diagnosis of neurofibromatosis type 1 (NF-1), complaining of low back and cervical spine pain with bilateral upper extremity paresthesias.

CLINICAL FEATURES

The patient had a dull, achy, constant low-back pain of 4 months' duration, with mild headaches and upper extremity paresthesias. Multiple skin lesions and spinopelvic postural imbalances were present. Diagnostic radiography, along with advanced imaging, demonstrated multilevel dysplastic osseous changes, with dural ectasia, scoliosis, and tumor extension. In addition to the previous diagnosis of NF-1, our clinical diagnosis included segmental dysfunction with resultant cervicalgia, lumbalgia, and myospasm.

INTERVENTION AND OUTCOME

Treatment consisted of a course of spinal manipulation of the lumbopelvic region, with adjunctive therapy consisting of interferential therapy, heat, and rehabilitative exercise. Marked reduction in pain and paresthesia with improved function were achieved.

CONCLUSIONS

NF-1 is a multisystem disease with neoplasia of the skin and nervous system. Patients experience a lifetime of morbidity and increased risk of mortality, depending on the extent of the disease. A multitude of therapeutic regimens may be engaged to improve NF-1-associated symptomatology and morbidity. Chiropractic spinal manipulation may have a positive effect in pain reduction and improved function in patients who have NF-1 without spinal instability.

Neurofibromatosis 1: clinical manifestations and diagnostic criteria

Neurofibromatosis 1 occurs in 2 to 3 people per 10,000. The most frequent clinical features are café-au-lait macules, neurofibromas, intertriginous freckling, Lisch nodules, and learning disabilities, but optic and other gliomas, malignant peripheral nerve sheath tumors, and characteristic osseous lesions also can be present. Two striking aspects of neurofibromatosis 1 are its progressive nature and its extreme variability. This article reviews the natural history and some important clinical manifestations of neurofibromatosis 1, with emphasis on features that constitute the standard diagnostic criteria. The pathogenic implications of these clinical manifestations are also considered.

[Tumors diagnosed in 65 patients with type I neurofibromatosis]

BACKGROUND

Type 1 neurofibromatosis patients develop malignant neoplasm more frequently than general population.

PATIENTS AND METHOD

We have studied 65 patients with neurofibromatosis type 1 because we intend to know the kind of neoplasms that they have presented.

RESULTS

65 patients (48 men and 17 women) fulfilling type 1 neurofibromatosis criteria have been studied. Globally 67 tumors appeared, from which 47 (70%) were benign and 20 (30%) were malignant. Benign tumors included 25 neurofibromas, 11 central nervous system tumors and 11 extraneurological tumors. Malignant tumors accounted for 6 soft tissue sarcomas, 6 carcinomas, 3 malignant CNS tumors and 2 acute lymphoblastic leukemias.

CONCLUSION

Presentation of neoplasms is frequent in type 1 neurofibromatosis and constitutes main death and morbility cause.

Electro-oculogram in patients with neurofibromatosis type 1

PURPOSE

The electro-oculogram (EOG) is a powerful test to evaluate the functional status of the retinal pigment epithelium (RPE). Clinically detectable changes of the RPE desribed in neurofibromatosis type 1 (NF-1) patients include combined hamartoma of the retina/RPE and congenital hypertrophy of the RPE. The goal of this study was to determine whether the function of RPE as measured by EOG is also changed in individuals with NF-1.

PATIENTS

Studies were undertaken in 20 patients with clinically diagnosed NF-1 and compared to 16 normal healthy controls.

METHODS

Standard EOG and flash ERG recordings were performed in accordance with International Society for Clinical Electrophysiology of Vision (ISCEV) standards.

RESULTS

In NF-1 patients the Arden indexes of the EOG test were significantly higher primarily due to the lower values of dark troughs. Supernormal EOGs were present in 60% of NF-1 patients in comparison to the control group mean +2 SD. No one patient showed so high abnormalities during flash ERG examination.

CONCLUSIONS

Dysfunction of the RPE may be characteristic feature of individuals with NF- 1.

Abdominal migraine in children with neurofibromatosis type 1: a case series and review of gastrointestinal involvement in NF1

BACKGROUND

Symptomatic involvement of the gastrointestinal tract in children with neurofibromatosis type 1 (NF1) is rare. Most reported complications in adults are caused by the presence of neurofibromas in the stomach, small bowel, or mesentery. In contrast, abdominal pain in children with NF1 may be the result of nonanatomic causes, such as migraine. There are no previous reports of an association between abdominal migraine and NF1.

METHODS

Children with abdominal migraine were identified from a group of children with NF1, all of whom had been followed up for a minimum of 3 years. Medical records of cases were reviewed independently by two authors. MEDLINE was searched via PubMed for all reports of children with NF1 and any associated gastrointestinal involvement.

RESULTS

Six children with NF1 and intermittent, episodic, severe abdominal pain are reported. Investigations for obstructive or inflammatory causes of abdominal pain were negative. All patients had previously been diagnosed with migraine headaches by a neurologist. In five of the six patients, propranolol (10-15 mg three times daily) resulted in relief of their abdominal pain within days of starting therapy. Our review identified 24 children in the medical literature with gastrointestinal complications of NF1, mostly secondary to visceral neurofibromas. In almost all of these cases, clinical examination and simple radiologic investigations led to the definitive diagnosis. There were no reports of abdominal migraine complicating NF1.

CONCLUSIONS

Abdominal pain secondary to migraine is an unrecognized cause of abdominal pain in children with NF1 and may be more common than anatomic causes of abdominal pain in children with NF1. In children with NF1 and severe recurrent abdominal pain in whom an evaluation for anatomic lesions is negative, a trial of migraine therapy may be indicated.

von Recklinghausen's disease and pheochromocytomas

PURPOSE

We review the literature and characterize the clinical findings of von Recklinghausen's associated pheochromocytoma.

MATERIALS AND METHODS

A Grateful Med search for the years 1966 to 1999 was performed on the subjects, "von Recklinghausen" and "neurofibromatosis." Articles from the Grateful Med search were then reviewed to identify older publications. Of 325 articles 118 are included in this review.

RESULTS

Pheochromocytomas have been clinically identified in 0.1 to 5.7% of patients with von Recklinghausen's disease. Mean patient age was 42 years (range 1.5 to 74) in 87 women and 61 men at presentation with pheochromocytoma. Of the 148 patients 84% had solitary adrenal tumors, 9.6% bilateral adrenal disease and 6.1% ectopic pheochromocytomas. Symptoms related to pheochromocytoma or hypertension were noted in 78% of the patients. Tumors secreted epinephrine and norepinephrine, and 87% demonstrated metaiodobenzylguanidine uptake. Of the 148 patients 6% died during pregnancy or a medical procedure, or due to hypertensive crisis without apparent provocation, 8.8% had gastrointestinal carcinoid tumors and 11.5% had metastases or local invasion from pheochromocytoma.

CONCLUSIONS

Pheochromocytomas occur in a small but defined number of patients with von Recklinghausen's disease, and can be associated with significant morbidity and mortality if not detected. Screening of patients with von Recklinghausen's disease and hypertension or before provocative procedures or pregnancy seems to be indicated.