Neurofibromatosis Research Articles

7694 Characterizing NF1 Germline Pathogenic Variants In A Cohort Of Patients With Pheochromocytomas And Neurofibromatosis Type 1

Abstract Disclosure: T. Hristova: None. S. Parisien-La Salle: None. S. Lapointe: None. D. Tremblay: None. N. Dumas: None. M. Labidi: None. Z. El Haffaf: None. I. Bourdeau: None. Introduction: Pheochromocytomas and paragangliomas (PPGLs) are the tumors with the highest heritability in adult patients, with identification of a germline mutation in more than 30% of cases. Up to 20 susceptibility genes for PPGLs are known, including NF1. Neurofibromatosis type 1 (NF1) is an inherited disease affecting approximately 1 in 3000 people that predisposes to the development of tumors, such as pheochromocytomas (PHEO). Up to recently, the diagnosis of NF1 was mainly based on clinical manifestations and NF1 genetic characterization was not systematically performed. Objectives: To characterize germline pathogenic variants in the NF1 gene in patients with NF1 developing and PHEO. Methods: We reviewed the charts of patients with a pathology-proven diagnosis of PHEOs that were investigated at Centre hospitalier de l’Université de Montréal (CHUM) between 2000 and May 2023. Genetic analysis included gene sequencing by Sanger method or multigene sequencing by NGS with a panel (Invitae, CA) Results: In our cohort of 220 PHEOs, 15 patients (6.8%) (Males: 6, Females: 9) had a diagnosis of NF1. Mean age at diagnosis of PHEO in NF1 patients was 48 ± 13.6 years, contrasting to the mean age of 38,7 ± 15.2 years in patients carrying germline mutations in non-NF1 genes, most likely reflecting lack of systematic biochemically screening of PHEO in NF1. Urinary metanephrines were elevated in 9/15 patients. 2/15 (15.4%) NF1 patients had bilateral PHEO and 1/15 (7,7%) metastatic disease. Mean tumour diameter was 4.64cm (min-max 1.5 – 12.5 cm). Eight out of 15 NF1 patients underwent NF1 genetic analysis. Heterozygous NF1 germline pathogenic variants were found in all of them: 3 deletions (c.7379delG, c.5844_5845delAA and one encompassing the entire gene), 3 premature stop codons leading to truncated proteins or loss of function (c.7549C>T, c.3916C>T, c.1246C>T), and 2 splicing defects (c.4269+1 G>A, c.1885G>A). Conclusions: We report a large cohort of patients with NF1 and PHEO. The older age at diagnosis of PHEO in NF1 is expected based on lack of systematic biochemical screening for PHEO in NF1 clinical guidelines. We report 8 germline NF1 mutations associated with PHEOs. Further studies are required to fully understand the impact of genetic pathogenic variants in this population and to unravel a possible genotype-phenotype correlation. Presentation: 6/2/2024

5118 When Thyroid Gland Is Not Made Of Thyroid Cells

Abstract Disclosure: A. Bulut: None. L. Ma: None. J.P. Noordzij: None. S.Y. Lee: None. Introduction: Neurofibroma is a type of peripheral nerve tumor that can arise sporadically or be a part of neurofibromatosis type 1 (NF1), a rare genetic disorder. Neurofibromas within the thyroid gland are extremely rare. Here, we present the fifth reported case of primary neurofibroma of thyroid gland. Case: A 60-year-old woman with history of systemic lupus erythematosus and hypertension presented with enlargement of left thyroid gland. She was diagnosed with Graves’ disease 40 years ago, which was treated with right thyroid lobectomy one year after the initial diagnosis. Five years after the surgery, she had recurrence of her symptoms and received radioactive iodine ablation with subsequent hypothyroidism. On presentation to endocrine clinic, she had thyroid ultrasound (US), which showed surgically absent right thyroid lobe and enlarged heterogenous left thyroid lobe measuring 5.1 cm x 3.8 cm x 3.9 cm with scant blood flow without discrete nodules. In interim, patient developed dysphagia and globus sensation. Repeat thyroid US showed enlargement of left lobe to 5.6 cm x 3.7 cm x 4.7 cm. Patient underwent completion thyroidectomy. Surgical pathology showed neurofibroma (S-100+, CD34+ and MSA-) without any thyroid parenchyma. Whole-body scan revealed no other evidence of tumors. Patient was referred for genetic analysis. Discussion: Neurofibromas are benign peripheral nerve system tumors primarily consist of Schwann cells along with other components of perineurium. They can occur as a sporadic lesion which accounts for 90% of solitary neurofibroma cases or be a part of NF1 on rare occasions. NF1 is an autosomal dominant genetic disorder due to germline mutation in NF1 gene located on chromosome 17q11.2, whose manifestations include café-au-lait macules, Lisch nodules, skeletal abnormalities, neurological deficits, and other benign and malignant tumors. Neurofibromas are the hallmarks of NF1. There are only few cases in the literature reported neurofibromas adjacent to or originating from thyroid gland. To the best of our knowledge, there have been only four other cases reporting primary neurofibroma of thyroid gland, one of which developed from thyroid capsule. Our patient most likely has primary neurofibroma of thyroid gland given the lack of syndromic features, however, genetic testing is needed in order to rule out NF1. In conclusion, clinicians should consider neurofibroma in their differential in cases of enlarging thyroid gland or nodules, especially in the presence of other clinical features. Presentation: 6/1/2024

5118 When Thyroid Gland is Not Made of Thyroid Cells

Abstract Disclosure: A. Bulut: None. L. Ma: None. J.P. Noordzij: None. S.Y. Lee: None. Introduction: Neurofibroma is a type of peripheral nerve tumor that can arise sporadically or be a part of neurofibromatosis type 1 (NF1), a rare genetic disorder. Neurofibromas within the thyroid gland are extremely rare. Here, we present the fifth reported case of primary neurofibroma of thyroid gland. Case: A 60-year-old woman with history of systemic lupus erythematosus and hypertension presented with enlargement of left thyroid gland. She was diagnosed with Graves’ disease 40 years ago, which was treated with right thyroid lobectomy one year after the initial diagnosis. Five years after the surgery, she had recurrence of her symptoms and received radioactive iodine ablation with subsequent hypothyroidism. On presentation to endocrine clinic, she had thyroid ultrasound (US), which showed surgically absent right thyroid lobe and enlarged heterogenous left thyroid lobe measuring 5.1 cm x 3.8 cm x 3.9 cm with scant blood flow without discrete nodules. In interim, patient developed dysphagia and globus sensation. Repeat thyroid US showed enlargement of left lobe to 5.6 cm x 3.7 cm x 4.7 cm. Patient underwent completion thyroidectomy. Surgical pathology showed neurofibroma (S-100+, CD34+ and MSA-) without any thyroid parenchyma. Whole-body scan revealed no other evidence of tumors. Patient was referred for genetic analysis. Discussion: Neurofibromas are benign peripheral nerve system tumors primarily consist of Schwann cells along with other components of perineurium. They can occur as a sporadic lesion which accounts for 90% of solitary neurofibroma cases or be a part of NF1 on rare occasions. NF1 is an autosomal dominant genetic disorder due to germline mutation in NF1 gene located on chromosome 17q11.2, whose manifestations include café-au-lait macules, Lisch nodules, skeletal abnormalities, neurological deficits, and other benign and malignant tumors. Neurofibromas are the hallmarks of NF1. There are only few cases in the literature reported neurofibromas adjacent to or originating from thyroid gland. To the best of our knowledge, there have been only four other cases reporting primary neurofibroma of thyroid gland, one of which developed from thyroid capsule. Our patient most likely has primary neurofibroma of thyroid gland given the lack of syndromic features, however, genetic testing is needed in order to rule out NF1. In conclusion, clinicians should consider neurofibroma in their differential in cases of enlarging thyroid gland or nodules, especially in the presence of other clinical features. Presentation: 6/1/2024

8563 Pheochromocytoma Screening In A Patient With Neurofibromatosis Type I And Medication-Resistant Hypertension

Abstract Disclosure: E. Mora: None. A. Bolduc, MD: None. G. Elshimy: None. Title: Pheochromocytoma Screening in a Patient With Neurofibromatosis Type I and Medication-Resistant Hypertension Background: Patients with neurofibromatosis type I (NF1) have a higher risk of pheochromocytoma and it may be missed if no screening done, thus placing the patient at risk of stroke and/or myocardial infarction. The prevalence of pheochromocytoma in patients with NF1 is 2.9% according to a retrospective cohort study by Gruber et al. We present a case of biochemically silent pheochromocytoma in a patient with NF1 and resistant hypertension Clinical case: A 74-year woman with NF1 presented with episodic headaches and labile systolic blood pressure (BP) in the 170-200s mm Hg on three different antihypertensives consistent with pheochromocytoma. Initial tests for renal artery stenosis and pheochromocytoma showed normal plasma MN (0.43 nmol/L, n< 0.50 nmol/L) and NM (0.86 nmol/L, n< 0.90 nmol/L), and normal flow in both renal hila by color Doppler and no large suprarenal masses identified on retroperitoneal US. Duplex imaging of the bilateral kidneys showed no evidence of renal artery stenosis. CT of abdomen/pelvis with and without IV contrast showed a 1.6 cm nodule on Right (RT) adrenal gland that measured 36 HU on unenhanced phase with an absolute washout of 67%. No discrete nodule in Lt adrenal gland. Dotatate PET/CT revealed a Rt adrenal nodule with elevated asymmetric activity (measured 28.1 standardized uptake values (SUV), n for liver: max 12.3, spleen: max 23.5) relative to the normal physiologic activity of the Leftt adrenal gland, which is concerning for pheochromocytoma. The patient was then referred to our endocrine clinic for further evaluation 6 months after the initial presentation. Labs showed normal aldosterone (5.8 ng/dL, n≤39.2 ng/dL), cortisol (7.66 mcg/dL, n: 3.09-22.40 mcg/dL), ACTH (20 pg/mL, n: 7.2-63 (AM collection), and DHEA-S (28 mcg/dL, n:5.3-124 mcg/dL). Normal repeat plasma MN (0.38 nmol/L, n< 0.50 nmol/L) and NM (0.46 nmol/L, n< 0.90 nmol/L). Repeat CT adrenal washout redemonstrated 1.4 cm Rt adrenal nodule that measured 39 HU on non- contrast image with an absolute washout of 68%. Patient will have a surgical resection of the Rt adrenal biochemically silent pheochromocytoma next week and she has been receiving an alpha-blocker prior to surgery to decrease risk for labile BP. Discussion and Conclusion: This case illustrates how CT and DOtatate scan findings can alert providers to the presence of a pheochromocytoma, even in biochemically negative patients. We recommend pheochromocytoma screening in all patients with NF1 to prevent delayed diagnosis and complications of untreated pheochromocytoma. Presentation: 6/1/2024

8291 Graves’ Disease and Moyamoya Syndrome: A Complex Case of Thyroid Dysfunction and Neurovascular Abnormalities

Abstract Disclosure: A. Jamil: None. Q.V. Luong: None. A. Llorens Bonilla: None. A. Siddiqui: None. Background: Moyamoya disease is a cerebrovascular disease characterized by progressive stenosis and occlusion of cerebral arteries, particularly the internal carotid arteries, proximal anterior and middle cerebral arteries associated with a net-like collateral vessel formation. Moyamoya disease in association with certain systemic conditions (e.g. Graves’ disease, sickle cell anemia, neurofibromatosis type 1, and Down Syndrome) has been referred to as moyamoya syndrome. Graves’ disease is an autoimmune disease in which the development of thyroid-stimulating hormone (TSH) receptor autoantibodies leads to overproduction of thyroid hormones. Although the pathophysiology is unclear, Graves’ disease can adversely impact the clinical course of moyamoya syndrome.Clinical Case: A 26-year-old woman diagnosed with Graves’ disease at the age of 20 years who was in remission presented to the ED with right upper extremity weakness and headache. A stroke work-up was performed, and an initial CT head without contrast showed an acute infarct in the left temporal area. Extensive workup for hypercoagulability and cardiac causes were negative. MRI brain showed multiple infarcts of the left cerebral hemisphere with ivy sign, which are prominent linear or punctate high intensity areas in the subarachnoid space reflecting the development of collaterals that occurs in moyamoya disease. TSH at the time was noted to be <0.01 uIU/mL (range: 0.30-4.20 uIU/mL), indicating a thyrotoxic state. She was discharged on methimazole and antiplatelet therapies. However, the patient continued to have hypertension and headaches which did not resolve with the return to euthyroidism. At age 29, she again developed acute right upper and lower extremity weakness, and consequently presented to the ED. Imaging studies showed multiple punctate infarcts in her bilateral frontal lobes and bilateral ICA stenosis consistent with moyamoya disease. However, her biochemical studies showed euthyroidism. Ultimately, she underwent right frontotemporal craniotomy and direct parietal superficial temporal artery to middle cerebral artery bypass by neurosurgery to decrease her future stroke risk for her moyamoya syndrome, and her Graves’ disease remains in remission.Conclusions: The coexistence of Graves’ disease in moyamoya syndrome may suggest a pathophysiologic connection. It has been suggested that hemodynamic changes in cerebrovascular flow due to thyrotoxicosis might contribute to ischemic neurologic deficits. Surgical intervention for revascularization procedures should be attempted after optimal control of thyrotoxicosis, as this may help to prevent further ischemic events in the future and improve patient outcomes. Presentation: 6/1/2024

7109 "My Stomach hurts": A Rare Case of Adrenal Cortical Carcinoma

Abstract Disclosure: R.C. Attah: None. I. Sirisena: None. Pheochromocytoma/Paragangliomas are rare neurogenic tumors that arise from chromaffin cells present in the adrenal medulla or extra-adrenal paraganglia, these cells produce catecholamines. Typically, these tumors are discovered as incidentalomas. They can be hereditary as seen in genetic syndromes like multiple endocrine neoplasia type 2A or 2B, neurofibromatosis type 1 or Von Hippel Lindau syndrome but can occur sporadically. Patients typically present with hormonal hypersecretion signs or symptoms like abdominal pain, episodic headaches, sweating, hypertension and tachycardia, but some patients are asymptomatic. Patient is a 37-year-old female with past medical history of hypertension, type 2 diabetes mellitus and fatty liver who presented to the ED with abdominal pain for a few weeks. On arrival, her vitals were BP 205/124, HR 102, RR 14 and SpO2 100% on room air. CT abdomen was obtained which showed a 7.6 x 4.7 x 5.7 cm mass replacing left adrenal gland with small left retroperitoneal hemorrhage worrisome for adrenal cortical carcinoma, metastatic disease or pheochromocytoma. Hormonal workup revealed elevated 24-hr urine cortisol 124.2mcg (ref 4.0-50.0mcg/24h), normal aldosterone/renin ratio 10.63ng/dL (ref <30ng/dl), failed low dose dexamethasone suppression test with post-dex AM cortisol 7.20ug/dL (ref <1.8ug/dL), slightly elevated serum total catecholamine 1256pg/mL (242-1125 pg/mL), norepinephrine 1155pg/mL (ref 217-1109 pg/mL), total metanephrine and normetanephrine 341pg/mL (reg <205 pg/mL), normetanephrine 244.1 (ref <210.1pg/mL), elevated 24-hr urine normetanephrine 700ug/L (ref 131-612ug/L), metanephrine 136ug/L (ref 36-209ug/L) and DHEA-s level 285ug/dl (ref 23-266ug/dL). Due to elevation in cortisol, adrenal cortical carcinoma was suspected as these tumors are frequently associated with cortisol secretion. However, pheochromocytoma with co-secretion of ACTH could not be excluded. She was started on doxazosin for alpha blockade and eventually started on beta blockade with Metoprolol. She underwent a left adrenalectomy and was started on steroid taper post-op due to concern of cortisol co-secretion. Surgical pathology was positive for Left adrenal malignant pheochromocytoma and ganglioneuroma. Genetic panel was negative with no mutation identified in the 54 gene Hereditary paraganglioma-pheochromocytoma panel. This patient had a large adrenal tumor (>4cm mass) but mildly elevated catecholamines which could have led to misdiagnosis as her catecholamine levels were less than 2-3x ULN which is unusual for pheochromocytomas. Roughly 25% of people with pheochromocytoma are undiagnosed throughout their lifespan. This condition can be life-threatening, hence early diagnosis and intervention can be lifesaving. Prognosis of malignant pheochromocytoma is dependent on tumor size, presence of SDHB gene mutation or visceral metastases. Presentation: 6/1/2024

Whole-exome sequencing reveals the genetic causes and modifiers of moyamoya syndrome

Moyamoya vasculopathy secondary to various genetic disorders is classified as moyamoya syndrome (MMS). Recent studies indicate MMS occurs due to a combination of genetic modifiers and causative mutations for the primary genetic disorders. We performed whole-exome sequencing (WES) in 13 patients with various genetic disorders who developed MMS. WES successfully revealed the genetic diagnoses of neurofibromatosis type 1 (NF-1), Down syndrome, multisystemic smooth muscle dysfunction syndrome, Noonan syndrome, and alpha thalassemia. The previously reported modifier genes, RNF213 and MRVI1, were confirmed in the NF-1 and Down syndrome cases. Further analysis revealed rare hypomorphic variants in the causative genes of the primary disorders underlying MMS, such as Alagille syndrome and Rasopathies, conferred susceptibility to MMS. Genes involved in the development of pulmonary arterial hypertension (PAH), such as ABCC8 and BMPR2, were also identified as potential modifiers. The rare variants in the MMS and PAH genes were significantly enriched in the eight Japanese patients with MMS compared with the 104 Japanese individuals from the 1000 Genomes Project. Disease genes associated with the arterial occlusive conditions represented by those of Rasopathies and PAH may provide novel diagnostic markers and future therapeutic targets for MMS as well as moyamoya disease with an unknown cause.

Neurofibromatosis Type 1 and Psychiatric Disorders: A Case Report and Literature Review

Neurofibromatosis Type 1 and Psychiatric Disorders: A Case Report and Literature Review

Management and Treatment of Neurofibromatosis Type I

Neurofibromatosis type 1 (NF1) is an autosomal dominant tumour suppressor syndrome associated with benign and malignant tumours, predominantly affecting the skin and nervous system. NF1, the most prevalent neurocutaneous syndrome, and the focus of this review, has a frequency of ~ 1/1,900-1/3,500 people worldwide. Disease manifestations can present at birth and emerge with age, negatively impacting multiple clinical domains and imparting a profound impact on a patient’s quality of life and life expectancy. Given its progressive nature and marked clinical variability, NF1 warrants a multidisciplinary approach to management and treatment.

Long-term analysis of ABI auditory performance in patients with neurofibromatosis type 2-related schwannomatosis.

This retrospective monocentric study aimed to evaluate long-term auditory brainstem implant (ABI) function in patients with neurofibromatosis type 2, and to investigate the prognostic factors for ABI use. Between 1997 and 2022, 27 patients with at least five years of follow-up underwent implantation with 32 ABIs. At 1- and 5-years post-implantation and at last follow-up, ABIs were classified as used or non-used and the size of the ipsilateral tumor was recorded. For patients who used their ABIs, we assessed speech perception (disyllabic words, MBAA sentences) in quiet conditions with the ABI only, by lip-reading (LR), and with a combination of the two (ABI + LR). Hearing improvement was calculated as ABI = (ABI + LR)-LR scores. Predictive factors for ABI use were analyzed. One year post-implantation, 74% patients were ABI-users and 66% of the ABIs were used. Two of these patients were non-users at five years, and another two at last follow-up (14 ± 5.2years); 54% of the patients were ABI-users at last follow-up. ABI revealed a hearing improvement of 32-41% (disyllabic words) and 28-37% (MBAA sentences). Among 16 ABIs with at least LR improvement at 1-year post-implantation, 4 decreased their performance, coinciding with a large growing ipsilateral tumor in 3/4 ABIs. We identified no significant prognostic factors for ABI use. ABIs are indicated in case of bilateral deafness with a non-functional cochlear nerve. Half the patients with ABIs used their implants and auditory performance remained stable over time, except in cases of ipsilateral tumor growth.

Recurrence of spinal schwannomas in a patient with neurofibromatosis type 1: a case report

Introduction and importance: Spinal schwannomas are benign tumors usually attached to peripheral nerves, consisting of a clonal population of Schwann cells. Neurofibromatosis type 1 is an autosomal dominant neurocutaneous disorder that predominantly affects the skin, bone and nervous system. Neurofibromatosis type 1 is a clinically and genetically distinct from neurofibromatosis type 2. This case report highlights the rare association between spinal schwannoma and neurofibromatosis type 1. Case presentation: The patient with a past medical history of spinal schwannoma, operated 1 year back, presented with back pain, weakness of lower limbs and urge incontinence. On examination, she had cutaneous features suggestive of neurofibromatosis type 1 and there was impairment of all sensory modalities below hip region. MRI revealed spinal schwannoma at D9 level for which laminectomy with removal of schwannoma was performed. Clinical discussion: The occurrence and recurrence of spinal schwannoma in neurofibromatosis type 2 is a common finding. But such an association has not been established between spinal schwannoma and neurofibromatosis type 1. In this case, the recurrence of spinal schwannoma has been linked to neurofibromatosis type 1 in the absence of other well-defined etiologies. Conclusion: The occurrence of spinal schwannoma can be genetic or sporadic. The recurrence is usually associated with familial tumor syndrome. The available literature has not established association between neurofibromatosis type 1 and spinal schwannoma, thus, emphasizing the need of more focused studies.

T2 Hyperintensities in Children with Neurofibromatosis Type 1

Areas of increased signal intensity, known as T2 hyperintensities (T2Hs), observed on T2-weighted magnetic resonance imaging (MRI) scans, are linked to a spectrum of brain abnormalities in children with neurofibromatosis type 1 (NF1). Defining the radiological characteristics that distinguish non-neoplastic from neoplastic T2Hs in children with NF1 is crucial. Then, we could identify lesions that most likely to require oncologic surveillance. We conducted a single-center retrospective review of all available brain MRIs from 98 children with NF1 and 50 healthy pediatric controls. All T2Hs identified on MRI were characterized based on location, imaging features, presence of lesion related symptoms. Subsequently, all T2Hs were classified using newly established criteria and categorized into three distinct groups: low-risk tumor lesions, medium-risk tumor lesions, and high-risk tumor lesions. Lesions deemed to be high-risk will be recommended for surgical treatment. T2Hs were present in 61 (62.2%) individuals of the NF1 cohort. T2Hs were a highly sensitive (100%; 95% confidence interval [CI] 92.9%-100.0%) and specific (62.2%; 95% CI 51.9%-71.8%) marker for the diagnosis of NF1. In children aged 4-10, the detection rate of T2Hs is significantly higher than in children under 4 years old and those aged between 10 and 18(P<0.05). T2Hs were most frequently located in basal ganglia, cerebellar hemispheres, and brainstem. During the follow-up process, none of lesions categorized as low-risk or medium-risk tumor lesions progressed to high-risk tumor lesions. Seven patients had high-risk tumor lesions and underwent surgical treatment.The pathological assessment identified 5 cases of glioma among the 7 patients, along with 1 case of gliosis and 1 case of vascular dysplasia. Low-risk and medium-risk tumor lesions can both be classified as unidentified bright objects(UBOs).UBOs constituted the majority of T2Hs in children with NF1. High-risk tumor lesions should be considered as probable tumors.With the application of standardized radiologic criteria, a high prevalence of probable brain tumors will be identified in this at-risk population of children, which underscores the importance of vigilant and appropriate oncological surveillance to ensure timely detection and intervention for these tumors.

Early Detection of Malignant and Premalignant Peripheral Nerve Tumors Using Cell-Free DNA Fragmentomics.

Early detection of neurofibromatosis type 1 (NF1)-associated peripheral nerve sheath tumors (PNST) informs clinical decision-making, enabling early definitive treatment and potentially averting deadly outcomes. In this study, we describe a cell-free DNA (cfDNA) fragmentomic approach that distinguishes nonmalignant, premalignant, and malignant forms of PNST in the cancer predisposition syndrome, NF1. cfDNA was isolated from plasma samples of a novel cohort of 101 patients with NF1 and 21 healthy controls and underwent whole-genome sequencing. We investigated diagnosis-specific signatures of copy-number alterations with in silico size selection as well as fragment profiles. Fragmentomics were analyzed using complementary feature types: bin-wise fragment size ratios, end motifs, and fragment non-negative matrix factorization signatures. The novel cohort of patients with NF1 validated that our previous cfDNA copy-number alteration-based approach identifies malignant PNST (MPNST) but cannot distinguish between benign and premalignant states. Fragmentomic methods were able to differentiate premalignant states including atypical neurofibromas (AN). Fragmentomics also adjudicated AN cases suspicious for MPNST, correctly diagnosing samples noninvasively, which could have informed clinical management. Novel cfDNA fragmentomic signatures distinguish AN from benign plexiform neurofibromas and MPNST, enabling more precise clinical diagnosis and management. This study pioneers the early detection of malignant and premalignant PNST in NF1 and provides a blueprint for decentralizing noninvasive cancer surveillance in hereditary cancer predisposition syndromes.

A successful combined spinal-epidural anesthesia for cesarean section in a patient with neurofibromatosis type 1-associated dural ectasia.

Dural ectasia is a common manifestation of neurofibromatosis type 1. Although there have been reports of unsuccessful spinal anesthesia due to dual ectasia in Marfan syndrome, reports describing similar unsuccessful spinal anesthesia in neurofibromatosis type 1 are lacking. A parturient with neurofibromatosis type 1 was scheduled for a repeat cesarean section. During a previous cesarean section, she had experienced a failed spinal anesthesia, which resulted in a conversion to general anesthesia. Preoperative lumbar magnetic resonance imaging revealed dural ectasia, which was speculated to be the cause of the previous spinal anesthesia failure. Therefore, combined spinal-epidural anesthesia was implemented. Because the block level of spinal anesthesia was insufficient as predicted, supplemental administration of epidural anesthesia successfully provided adequate analgesia for the surgery. Combined spinal-epidural anesthesia can be useful for the management of cesarean sections in patients with neurofibromatosis type 1-associated dural ectasia.

Unilateral retinitis pigmentosa in Von Recklinghausen disease: A rare occurrence

Retinitis pigmentosa (RP) is hereditary progressive retinal dystrophy causing symmetrical affliction of both eyes. Neurofibromatosis 1 (NF1)/Von Recklinghausen disease is a hereditary neurocutaneous disorder with ocular involvement. But, occurrence of retinitis pigmentosa in NF1 is very uncommon, and unilateral RP in this scenario is a rare occurrence. This case report is of a male patient with NF1 presenting with unilateral RP on ophthalmological examination. This case is being presented for its rarity.

8251 The Silent Thief: Neurofibromatosis Type 1 (NF1) Leading to Severe Osteoporosis and Recurrent Bone Fractures

8251 The Silent Thief: Neurofibromatosis Type 1 (NF1) Leading to Severe Osteoporosis and Recurrent Bone Fractures

Managing neurofibromatosis type I and vision impairment in a resource-limited setting: a case study and multidisciplinary approach

Background: Neurofibromatosis type I (NF1) is a genetic disorder characterized by the development of multiple benign tumors along nerves in the skin, brain, and other parts of the body. It is associated with a range of clinical manifestations, including skin lesions, neurofibromas, and ocular abnormalities, which can significantly impact a patient’s quality of life. Management of NF1 is particularly challenging in resource-limited settings due to limited access to diagnostic and therapeutic resources. Clinical presentation: A 62-year-old woman with a known history of NF1 presented with progressive visual impairment. Her condition began in childhood with multiple hyperpigmented skin macules, which developed into numerous cutaneous tumors over time. Examination revealed numerous neurofibromas, café-au-lait spots, and axillary freckling. Significant visual impairment was caused by large fibromas on her eyelids. Histological analysis confirmed benign nerve tissue tumors. Clinical discussion: The management strategy in this resource-limited setting focused on regular monitoring, patient education, symptomatic treatment, and multidisciplinary care. Despite the limitations, the patient’s condition was managed effectively through these adapted strategies. The importance of genetic testing for confirmation and further management was noted but not performed due to resource constraints. Conclusion: This case highlights the complexities of managing NF1 in resource-limited settings, emphasizing the need for adaptable management approaches. Multidisciplinary care and patient education were crucial in improving the patient’s quality of life. This case underscores the importance of early diagnosis and intervention to prevent complications like visual impairment.

Trapezius Island Myocutaneous Flap for Head, Neck, and Facial Reconstruction in Neurofibromatosis Type 1-Associated Plexiform Neurofibromas.

Reconstruction of significant soft tissue defects in the head and neck region after resection of extensive plexiform neurofibromas, as well as preservation and restoration of cosmetic and functional aspects, presents a considerable challenge. The purpose is to evaluate the feasibility of eTMF in repairing substantial defects after the complete resection of NF1 PN. Patients diagnosed with substantial neurofibromatosis (NP) type 1 (NF1), according to the revised criteria, underwent complete resection and remodeling of the facial aesthetic unit. An extended vertical lower trapezius island myocutaneous flap (eTIMF) was used for the defect reconstruction. Perioperative complications were evaluated using the Clavien-Dindo classification. ECOG PS was assessed. Postoperative follow-up at 6 months and completion of UW-QOL. The questionnaire included swallowing, chewing, speech, and quality of life scores. Two patients had pathogenic missense variants: c.5609G>A (p.Arg1870Gln) in exon 38 of NF1 in the first case, and c.4600C>T (p.Arg1534*) in exon 35 in the second case. Two eTMFs were harvested successfully. Five facial esthetic units were remodeled, and 4 units were remodeled. Two extensive tumors were nearly entirely removed. No severe complications were noted. The ECOG PS improved from grade 3 in the first week postsurgery to grade 0 by the eighth week. The UW-QOL results indicated that swallowing, chewing, and speaking functions returned to their preoperative levels, with a 40% improvement in quality of life, reaching 60% and 80%, respectively. eTMF to repair substantial defects following total resection of NF1 PN and facial esthetic unit remodeling enhances appearance, function, and psychosocial outcomes. This technique is safe, efficient, resource-conserving, and simple to implement.

Optic pathway gliomas in children: Clinical characteristics, treatment, and outcome of 95 patients in a single center over a 31-year period. Can we avoid radiotherapy?

Optic pathway gliomas (OPG) are rare tumors in children. Lesion extent, visual functions, neurofibromatosis 1 (NF1), and age are factors that guide treatment. This study evaluates the clinical characteristics, treatment, and outcome of children and adolescents with OPG treated over a 31-year period in a single center. Ninety-five patients with OPG diagnosed between January 1990 and December 2021 were retrospectively evaluated. First-line chemotherapy regimen consisted of vincristine and carboplatinum for 1year. Radiotherapy was not used as first-line treatment and tried to be avoided in the ones who progressed after first-line treatment. Ninety-five children (44 male, 51 female) with a median age of 52 (1-216) months were evaluated. Sixty-three (66.3%) had NF1 and 10 (10,5%) diencephalic syndrome. The most common presenting symptoms were visual abnormalities and/or proptosis, nistagmus, and behavioral changes. Twenty-one (22.1%) patients with NF1 had stable disease throughout the follow-up period and received no treatment. Sixty-three of 74 patients received treatment at diagnosis and 11 due to progression during follow-up. Only one adolescent received radiotherapy at progression. Patients who progressed, received further line systemic treatment (vinblastine; bevacizumab; vincristine-cisplatinum-etoposide). Ten-year overall survival in all patients, in patients with NF1, and without NF1 were 97.2%, 98%, and 95.8% (p>.05), respectively; 10-year progression-free survival (PFS) in all patients, in patients with NF1, and without NF1 were 71.6%, 85.7%, and 54.2% (p=.001), respectively. In children with symptomatic/progressive OPG, chemotherapy consisting of vincristine-carboplatinum (VC) is effective. Radiotherapy may be avoided, especially in patients with NF1.

Lamotrigine for cognitive deficits associated with neurofibromatosis type 1: A phase II randomized placebo-controlled trial.

To find proof-of-principle evidence for short-term treatment with lamotrigine to improve cognitive functioning of adolescents with neurofibromatosis type 1 (NF1). This was a double-blind, parallel-group, randomized, placebo-controlled clinical trial (the NF1-EXCEL trial: Examining the Cognitive and Electrophysiological benefit of Lamotrigine in Neurofibromatosis type 1; Clinicaltrials.gov identifier NCT02256124), with the aim of enrolling 60 adolescents with NF1 aged 12 to 17 years 6 months. The short-term study intervention was 200 mg of lamotrigine taken orally for 26 weeks. The primary outcome was performance IQ tested with the Wechsler Intelligence Scale for Children, Third Edition, complemented with secondary outcomes for visuospatial learning efficacy, visual perception, visual sustained attention, fine motor coordination, attention-deficit/hyperactivity problems, and executive functioning. We screened 402 adolescents with NF1, of whom 31 (eight females) entered the study. Complete-case analysis showed no effect of lamotrigine on either performance IQ (-0.23, 95% CI -6.90 to 6.44) or most secondary outcomes. Visual sustained attention showed a trend towards better performance in the lamotrigine group (-0.81, 95% CI -1.67 to 0.04). Lamotrigine did not improve cognitive functioning in adolescents with NF1. The small treatment effects make it unlikely that a larger sample size could have changed this conclusion.