A novel stop-gain NF1 variant in neurofibromatosis type 1 and bilateral optic atrophy without optic gliomas.

BACKGROUND: Neurofibromatosis type 1 (NF1) is a multisystem disorder that primarily affects the skin and peripheral nervous system and is caused by chromosomal abnormalities and mostly truncating variants in the NF1 gene. Ocular complications such as Lisch nodules and optic pathway gliomas (OPGs) can occur in NF1 patients. Herein, we report a novel NF1 variant in an NF1 patient with bilateral optic atrophy. METHODS: Ophthalmological examinations and genetic analyses were performed using targeted next-generation sequencing (NGS). RESULTS: A 14-year-old girl diagnosed with NF1 visited our hospital with decreased visual acuity (VA). The patient had no family history of NF1 or visual impairment. Brain and orbital magnetic resonance imaging revealed no remarkable findings. Ophthalmoscopy revealed temporal pallor of the optic discs, which was confirmed by optical coherence tomography findings of significant thinning of the circumpapillary retinal nerve fiber layer in both eyes. At 23 years of age, the decimal-corrected VA had deteriorated to 0.2 in the right eye and 0.1 in the left eye. Additionally, the targeted NGS panel revealed a novel heterozygous stop-gain variant (p.Tyr628Ter) in the NF1 gene; however, no pathogenic variants in OPA1 or the mitochondrial DNA were identified. CONCLUSIONS: A patient with NF1 without OPGs developed bilateral optic atrophy and carried a novel de novo stop-gain variant of NF1. Although the relationship between NF1 variants and bilateral optic atrophy remains unclear, further investigations are required.

Hemorrhagic Complication in Surgical Resection for Massive Plexiform Neurofibroma in Body Trunk: The Flow-Void Sign as a Predictor and Preoperative Embolization as Prevention.

BACKGROUND: Plexiform neurofibromas (PNs) are highly vascularized and potentially malignant tumors. Surgical resection of a PN can be complicated by perioperative hemorrhagic events (PHE), including excessive intraoperative blood loss and postoperative hematoma at the surgical site. This study aimed to evaluate the predictive factors of PHE and the usefulness of preoperative embolization for PN. MATERIALS AND METHODS: Consecutive surgical resections of 24 massive PNs in the body trunk with a maximum diameter > 5 cm in 22 patients between January 2015 and December 2020 were reviewed. Patient demographics, laboratory analyses, MRI findings, preoperative transcatheter arterial embolization (TAE), and pathological findings were evaluated between PNs with and without PHE, which consists of intraoperative blood loss over 15% of their estimated total blood volume and/or postoperative hematoma requiring surgical intervention or blood transfusion. RESULTS: PHE was observed in 7 out of 24 PNs (29.2%), with 5 events of excessive intraoperative bleeding and 2 postoperative hematomas. The PHE group (n = 7) showed a significantly higher flow-void effect inside the tumor on preoperative MRI than the non-PHE group (n = 17) (P = 0.0186). Preoperative TAE was not associated with PHE occurrence for the 24 PNs; however, it significantly reduced the PHE risk by 12 PNs with a flow-void sign (P = 0.00126). Other characteristics showed no significant differences between groups. CONCLUSION: The flow-void sign on MRI can be the only predictive factor of PHE in surgical resection for massive PNs in the body trunk. Preoperative TAE can reduce the PHE risk for PNs with a flow-void sign.

Use of balloon enteroscopy in preoperative diagnosis of neurofibromatosis-associated gastrointestinal stromal tumours of the small bowel: a case report.

Neurofibromatosis type I (NF1) is one of the most common inheritable disorders and is associated with an increased risk of gastrointestinal stromal tumours (GISTs). However, the predominant location of these lesions in the small bowel makes them difficult to diagnose. We report the successful use of balloon enteroscopy in conjunction with conventional methods for clinical diagnosis of jejunal GISTs in a 70-year-old man with NF1 who presented with melaena. The importance of screening NF1 patients for GISTs and the complementary role of balloon enteroscopy with capsule endoscopy in such diagnoses is discussed.