Prevalence of Endocrine Manifestations and GIST in 108 Systematically Screened Patients With Neurofibromatosis Type 1

Context

In patients with neurofibromatosis type 1 (NF1), guidelines suggest screening for pheochromocytoma by metanephrine measurement and abdominal imaging, which may lead to the discovery of gastroenteropancreatic neuroendocrine tumors (GEP-NETs) and their differential diagnosis, gastrointestinal stromal tumors (GISTs). Other endocrine manifestations such as follicular thyroid carcinoma and primary hyperparathyroidism have also been reported in a few cases.

Objective

This study aimed to describe prevalence and clinical presentation of these manifestations through systematic screening in a large cohort of patients.

Methods

In this monocentric retrospective study, 108 patients with NF1 were included and screened for endocrine manifestations and GISTs. Clinical, laboratory, molecular profile, pathology, and morphologic (abdominal computed tomography scan and/or magnetic resonance imaging) and functional imaging were collected.

Results

Twenty-four patients (22.2% of the cohort, 16 female, mean age 42.6 years) presented with pheochromocytomas that were unilateral in 65.5%, benign in 89.7%, and with a ganglioneural component in 20.7%. Three female patients (2.8% of the cohort, aged 42-63 years) presented with well-differentiated GEP-NETs, and 4 (3.7%) with GISTs. One patient had primary hyperparathyroidism, 1 patient had medullary microcarcinoma, and 16 patients had goiter, multinodular in 10 cases. There was no correlation between pheochromocytoma and other NF1 tumoral manifestations, nor correlations between pheochromocytoma and NF1 genotype, despite a familial clustering in one-third of patients.

Conclusion

The pheochromocytoma prevalence in this NF1 cohort was higher (>20%) than previously described, confirming the interest of systematic screening, especially in young women. The prevalence of GEP-NETs and GISTs was about 3%, respectively. No phenotype-genotype correlation was observed.

Iliofemoral Aneurysm in Patients with Type 1 Neurofibromatosis: A Case Report and a Literature Review

Vascular involvement, especially in the iliofemoral segment, is rare in type 1 neurofibromatosis. We herein report a case involving a 49-year-old male diagnosed with type 1 neurofibromatosis who presented with right inguinal pain and swelling. CT angiography revealed a 50-mm aneurysm extending from the right external artery to the common femoral artery. Although surgical reconstruction was performed successfully, the patient required an additional operation 6 years later for aneurysm enlargement in the deep femoral artery. Histopathological examination confirmed the proliferation of neurofibromatosis cells in the aneurysm wall.

Synchronous cutaneous malignant peripheral nerve sheath tumor and jejunal gastrointestinal stromal tumor and submucosal angiomyolipoma in type 1 neurofibromatosis: A case report and literature review

RATIONALE

Type 1 neurofibromatosis (NF1) is one of the most prevalent genetic conditions. NF1 is characterized by cutaneous plexiform neurofibromas and café au lait skin pigmentation, and is inherited in an autosomal dominant trait with mutation in the neurofibromin 1 gene on chromosome 17. Neurofibromin is involved in Ras proto-oncogene regulation. Accordingly, NF1 may lead to malignancies, with a lifetime cancer risk of 60%. Malignant peripheral nerve sheath tumor (MPNST) is the leading cause of mortality due to NF1. The relevance of gastrointestinal stromal tumor (GIST) in NF1 is increasingly being reported in the literature and NF1-associated GIST has been identified to have an alternative molecular pathogenesis.

PATIENT CONCERNS

A 62-years-old female had a 7 × 5 cm growing back mass in the background of various sized cutaneous neurofibromas with café au lait spots. Computed tomography performed in the workup revealed a 4.1 cm enhancing mass near the ileal mesentery.

DIAGNOSES

NF1 affected by cutaneous MPNST of the back, and synchronous GIST and submucosal angiomyolipoma (AML) of the jejunum.

INTERVENTIONS

The patient underwent laparoscopic jejunal mass excision, and excision and flap coverage for the back mass owing to the suspicion of multiple MPNSTs. However, the abdominal masses were diagnosed as GIST and AML following confirmation of the immunohistochemical profiles. Accordingly, the patient was administered adjuvant radiotherapy to the MPNST after surgery.

OUTCOMES

Symptomatic improvements were achieved, and no subsequent relapses were observed.

LESSONS

Although MPNST and GIST are not rare neoplasm in NF1, only 2 case reports have been published on the synchronous occurrence of these tumors. Moreover, no case report has been published on AML in NF1, except 1 renal AML in segmental neurofibromatosis. Identifying the clinical and pathologic significances of the NF1 is important to achieve improved diagnostic accuracy.

Idiopathic gross dilatation of the pancreatic duct with exocrine insufficiency in a patient with type 1 neurofibromatosis

Pancreatic duct dilatation occurs in conditions including chronic pancreatitis, pancreatic carcinoma and intraductal papillary mucinous neoplasms. Although several pancreatic benign and malignant tumours have been reported in association with type 1 neurofibromatosis, an association with gross pancreatic duct dilatation or ectasia has not been previously published. We report on a patient with type 1 neurofibromatosis found to have idiopathic gross pancreatic duct dilatation and exocrine insufficiency. A 51-year-old female with type 1 neurofibromatosis presented with weight loss and steatorrhoea. Computed tomography and magnetic resonance cholangiopancreatography showed a possible cystic lesion in the head of the pancreas, a grossly dilated main pancreatic duct and minimal thinned out pancreatic parenchyma. Endosonography confirmed diffuse dilatation of the pancreatic duct with no evidence of a separate cystic neoplasm. Endosonography-guided aspiration revealed non-mucinous, clear fluid with high amylase and normal carcinoembryonic antigen levels. The patient was prescribed pancreatic enzyme supplementation and showed symptomatic improvement. Associations between type 1 neurofibromatosis and pancreatic duct ectasia or chronic pancreatitis have not been reported, and this finding may be coincidental. Clinical presentation in conjunction with multimodal imaging and biochemical and cytological fluid analysis did not reveal the aetiology of the ectatic duct system and attenuated glandular tissue in this patient which is most likely congenital.

NF1-Associated Inflammatory Polyp of the Colon: First Report of a Sporadic Case

"Juvenile-like (hyperplastic/inflammatory) mucosal polyp" is a term proposed for rare benign mesenchymal lesions of the gastro-intestinal tract so far reported only in patients with type 1 neurofibromatosis (NF1). We report here a first sporadic case of NF1-associated mucosal inflammatory polyp of the colon. The diagnosis was made in a 53-year old female patient with a large polypoid tumor of the cecum. The lesion was predominantly mucosal, made of fibroblast-like cells associated with inflammatory infiltrates rich in eosinophils and containing entrapped, distorted epithelial glands, responsible for the juvenile-like appearance. Whole exome sequencing showed a pathogenic variant of NF1. The patient had no evidence of NF1; no NF1 mutation was detected in normal tissues. Our observation may support the existence of juvenile-like inflammatory polyps associated with NF1 alterations, either germline or somatic. This justifies to test NF1 in difficult-to-classify gastrointestinal mesenchymal tumors.

Type I Neurofibromatosis: Case Report and Review of the Literature Focused on Oral and Cutaneous Lesions

Neurofibromatosis type 1 (NF1) is a common genetic disease whose dermatological lesions are at the forefront of its development. Cutaneous manifestations include café au lait spots, intertriginous freckling, and neurofibromas which appear during childhood and adolescence and are part of the clinical criteria to diagnose NF1. However, it is only recently that oral manifestations have been highlighted in many studies as frequently associated to NF1. This article aims to review oral and cutaneous manifestations related to NF1 and to report a case of a 51-year-old male with skin and oral neurofibromas related to NF1. Our patient presented with lesions on the gingiva, a rare localization that takes a hypertrophic form mimicking other various pathological conditions. Although not frequent, malignant transformation in NF1, especially regarding plexiform neurofibromas, is well established. Patients with NF1 therefore have regular follow-ups based on clinical examination, as sarcomatous transformation brings an extremely poor prognosis, recurrences and distant metastasis being common.

Outcomes of growing rods in a series of early-onset scoliosis patients with neurofibromatosis type 1

OBJECTIVE

Early-onset scoliosis (EOS) is not uncommon in patients with neurofibromatosis type 1 (NF1). Despite conservative treatment, spinal deformities progress and require early surgical intervention. To avoid potential interference with chest and trunk growth, growing rods (GRs) have been used effectively in EOS of various etiologies. In this study the authors sought to analyze the outcomes of GRs in EOS patients with NF1.

METHODS

This was a retrospective single-center cohort study that included consecutive EOS patients with NF1 who were treated with GRs and were followed up for a minimum of 2 years. Clinical and radiological analyses were performed preoperatively and until the last follow-up.

RESULTS

From to 2008 to 2017, 18 patients (6 male, 12 female) underwent GR surgery (14 single GRs, 4 dual GRs) at a mean age of 8 ± 2.1 years. Mean follow-up was 5 ± 2.4 years. Fifty-five lengthenings were performed at a mean rate of 3 lengthenings per patient (range 0-7). Ten of 14 single GRs (71%) were converted into dual GRs during treatment. No patient underwent definitive posterior spinal fusion (PSF) at GR treatment completion. The mean initial and last follow-up major curves were 57° and 36°, respectively (p < 0.001, 37% correction). The average T1-S1 increase was 13 mm/yr. Six of 9 hyperkyphotic patients had normal kyphosis at last follow-up. There were 26 complications involving 13 patients (72%), with 1 patient who required unplanned revision. The primary complications were instrumentation related, consisting of 17 proximal hook dislodgments, 6 distal pedicle screw pullouts, and 2 rod fractures. Only 1 patient experienced a mechanical complication after dual GR implantation. There were no wound infections.

CONCLUSIONS

The GR technique provided satisfactory spinal deformity control in EOS patients with NF1 while allowing substantial spinal growth. Adequately contoured dual GRs with proximal hooks placed in nondystrophic regions should be used to minimize implant-related complications. Surgeons should not attempt to correct kyphosis at GR implantation.

Optic Pathway Glioma in Type 1 Neurofibromatosis: Review of Its Pathogenesis, Diagnostic Assessment, and Treatment Recommendations

Type 1 neurofibromatosis (NF1) is a dominantly inherited condition predisposing to tumor development. Optic pathway glioma (OPG) is the most frequent central nervous system tumor in children with NF1, affecting approximately 15-20% of patients. The lack of well-established prognostic markers and the wide clinical variability with respect to tumor progression and visual outcome make the clinical management of these tumors challenging, with significant differences among distinct centers. We reviewed published articles on OPG diagnostic protocol, follow-up and treatment in NF1. Cohorts of NF1 children with OPG reported in the literature and patients prospectively collected in our center were analyzed with regard to clinical data, tumor anatomical site, diagnostic workflow, treatment and outcome. In addition, we discussed the recent findings on the pathophysiology of OPG development in NF1. This review provides a comprehensive overview about the clinical management of NF1-associated OPG, focusing on the most recent advances from preclinical studies with genetically engineered models and the ongoing clinical trials.

Coexistence of cervical vertebral scalloping, pedicle deficiencies and dural ectasia in type I neurofibromatosis

Neurofibromatosis type 1 (NF-1; also known as Von Recklinghausen's disease) is a common autosomal dominant disease that occurs in the general population at the rate of 1 in 3000. Many NF-1 patients present with spinal malformations. A 54-year-old female patient was admitted to the Outpatient Clinic of Dermatology with gradually increasing swelling and spots on the body that had been present for a long period of time. Cervical vertebral scalloping, pedicle deficiencies and dural ectasia (DE) were also detected. She was diagnosed with NF-1. NF-1 is routinely seen in dermatology practice. Coexistence of NF-1 with vertebral scalloping, pedicle deficiencies and DE rarely occurs. Our case is the second reported instance in the literature of NF-1 with a spinal anomaly in the cervical region, and the first reported instance of the coexistence of NF-1 with cervical vertebral scalloping, pedicle deficiencies and DE.

An unusual oral manifestation of type 1 neurofibromatosis: A case report and review of literature

Neurofibroma is a benign peripheral nerve sheath tumor and is the most frequent tumor of neural origin. Its presence is one of the clinical criteria for the diagnosis of neurofibromatosis type 1 (NF1; a common hereditary disease occurring in one out of every 3000 births). The diagnosis can sometimes be made at birth, while in others the diagnosis is made later in life after the appearance of additional clinical criteria. Majority of the solitary neurofibromas are sporadic, while a few are associated with NF1 syndrome. Oral hard and soft tissue are affected by the tumor; however, the tongue is the most affected site. Gingival neurofibroma is an uncommon oral manifestation of NF. Here, we report a rare case of gingival neurofibroma in NF1 patient. One of the most feared complications of NF1 is its transformation into neurofibrosarcoma, which bears a very poor prognosis. Treatment of neurofibroma is surgical resection.

Is magnetic resonance spectroscopy capable of detecting metabolic abnormalities in neurofibromatosis type 1 that are not revealed in brain parenchyma of normal appearance?

BACKGROUND

Results of magnetic resonance spectroscopy studies in normal-appearing brain and in non-neoplastic brain lesions in individuals with neurofibromatosis type 1 (NF1) have been discrepant.

OBJECTIVE

We used magnetic resonance spectroscopy to analyze the metabolic patterns in the basal ganglia of patients with NF1 and examine their correlation with focal hyperintense lesions in T2-weighted images (T2-weighted hyperintensities).

METHODS

We used magnetic resonance spectroscopy data of 42 individuals with NF1 (18 with and 24 without T2- weighted hyperintensities) and 25 controls matched for gender and age. A single-voxel technique was employed by manually placing a region of interest with a uniform size over a predetermined anatomical region including the globus pallidum and putamen (capsulolenticular region). We further analyzed the ratios of choline/creatine, N-acetyl aspartate (NAA)/creatine, and myoinositol/creatine metabolites and the occurrence of T2-weighted hyperintensities in these regions in individuals with NF1.

RESULTS

There was a significant difference between the NF1 and control groups with regard to the mean values of myoinositol/creatine and choline/creatine, with higher metabolite values observed in the NF1 group (P < 0.001). Only the myoinositol/creatine ratio was able to discriminate between NF1 subgroups with and without T2-weighted hyperintensities. For the NAA/creatine ratio, there was no significant difference between the NF1 and the control groups.

CONCLUSION

Magnetic resonance spectroscopy allows the characterization of tissue abnormalities not demonstrable in the structural images of individuals with NF1 through choline and myoinositol metabolite analysis. Yet the preserved NAA values argue against demyelination and axonal degeneration occurring in the region, suggesting instead a functional neuronal stability. Taken in association with the findings of lack of clinical manifestations and the known transient nature of T2-weighted hyperintensities in NF1 as demonstrated by other studies, our results support the current histopathologically driven hypothesis that such T2-weighted hyperintensities may be related to intramyelinic edema.