A brief report of plexiform neurofibroma

Web in the Neck - An Interesting Case Report

Lateral neck masses are common in children, ranging from simple benign diseases to pathologies with malignant potential. Plexiform neurofibromas are extremely rare peripheral nerve sheath tumours involving multiple nerve sheath fascicles. They are typically seen in the paediatric population, with the majority affecting the craniofacial area and neck. Due to the close clinical and histological resemblance with other benign neck lesions such as lymphadenitis and branchial cysts, these cases can often go misdiagnosed. We describe a lesion in a young girl who presented with a progressive lateral neck swelling and how it was managed.

Neurofibromatosis Type 1: Pediatric Aspects and Review of Genotype-Phenotype Correlations

Neurofibromatosis type 1 (NF1) is an autosomal dominant condition, with a birth incidence of approximately 1:2000-3000, caused by germline pathogenic variants in NF1, a tumor suppressor gene encoding neurofibromin, a negative regulator of the RAS/MAPK pathway. This explains why NF1 is included in the group of RASopathies and shares several clinical features with Noonan syndrome. Here, we describe the main clinical characteristics and complications associated with NF1, particularly those occurring in pediatric age. NF1 has complete penetrance and shows wide inter- and intrafamilial phenotypic variability and age-dependent appearance of manifestations. Clinical presentation and history of NF1 are multisystemic and highly unpredictable, especially in the first years of life when penetrance is still incomplete. In this scenario of extreme phenotypic variability, some genotype-phenotype associations need to be taken into consideration, as they strongly impact on genetic counseling and prognostication of the disease. We provide a synthetic review, based on the most recent literature data, of all known genotype-phenotype correlations from a genetic and clinical perspective. Molecular diagnosis is fundamental for the confirmation of doubtful clinical diagnoses, especially in the light of recently revised diagnostic criteria, and for the early identification of genotypes, albeit few, that correlate with specific phenotypes.

Strangled by His Nerves-Cervical Plexiform Neurofibroma With Infantile Spinal Neurofibromatosis: Case Report in a 14 Years Old Child

Background

Neurofibromatoses are a rare group of autosomal dominant tumor suppressor phacomatoses syndromes. Neurofibromatosis type 1 (NF1 or Von Recklinghausen's disease) is the most commonly found type of neurofibromatosis, and constitutes the most commonly found autosomal dominant disease of the nervous system.

Case presentation

We report a case of a 14-year-old boy who reported a 3-year-history of a slowly enlarging right lateral cervical mass. He has a medical history of a progressive limping gait disorder with scoliotic attitude. MRI identified a dumb-bell shaped intradural right cervical process through right paravertebral gutter on C2 to C4, a second intradural dorsal mass with the same characteristics through left paravertebral gutter on D4 and D5 and a large tissue-like mass infiltrating the lumbosacral subcutaneous soft tissues. A Surgical excision of the cervical and lumbar masses was performed with a good outcome after surgical excision.

Conclusions

This case illustrates the need for a collaboration of both neurological and head and neck surgeons in terms of managing difficulties related to a cervical neurofibroma. Benign plexiform neurofibromas are rapidly growing tumors, particularly in children and adolescents, which makes all the importance of early detection and appropriate treatment. Repeated interventions are usually needed in order to adapt and stabilize the tumors extension.

Anatomy, Imaging, and Pathologic Conditions of the Brachial Plexus

The brachial plexus is an intricate anatomic structure with an important function: providing innervation to the upper extremity, shoulder, and upper chest. Owing to its complex form and longitudinal course, the brachial plexus can be challenging to conceptualize in three dimensions, which complicates evaluations in standard orthogonal imaging planes. The components of the brachial plexus can be determined by using key anatomic landmarks. Applying this anatomic knowledge, a radiologist should then be able to identify pathologic appearances of the brachial plexus by using imaging modalities such as MRI, CT, and US. Brachial plexopathies can be divided into two broad categories that are based on disease origin: traumatic and nontraumatic. In the traumatic plexopathy group, there are distinct imaging findings and management methods for pre- versus postganglionic injuries. For nontraumatic plexopathies, having access to an accurate patient history is often crucial. Knowledge of the timing of radiation therapy is critical to diagnosing post-radiation therapy brachial plexopathy. In acute brachial neuritis, antecedent stressors occur within a specific time frame. Primary and secondary tumors of the brachial plexus are not uncommon, with the most common primary tumors being peripheral nerve sheath tumors. Direct extension and metastasis from primary malignancies such as breast and lung cancer can occur. Although diagnosing a brachial plexus anomaly is potentially perplexing, it can be straightforward if it is based on foundational knowledge of anatomy, imaging findings, and pathologic features. ^©RSNA, 2020.

Trametinib for orbital plexiform neurofibromas in young children with neurofibromatosis type 1

INTRODUCTION

Plexiform neurofibromas (PNF) in neurofibromatosis type 1 (NF1) are usually diagnosed in childhood and can grow rapidly during this period. In 10% of patients, PNF involve the orbital-periorbital area and may cause visual problems including glaucoma, visual loss from amblyopia (deprivational, strabismic, or refractive), optic nerve compression, or keratopathy. Ptosis, proptosis, and facial disfigurement lead to social problems and decreased self-esteem. Complete surgical removal involves significant risks and mutilation, and regrowth after debulking is not uncommon. Inhibitors of the RAS/MAPK pathway have recently been investigated for their activity in PNF. We administered the oral MEK inhibitor trametinib to five young children with NF1 and PNF of the orbital area, with visual compromise and progressive tumor growth; and followed them clinically and by volumetric MRI.

METHODS

Treatment was initiated at a mean age of 26.8 months (SD ± 12.8) and continued for a median 28 months (range 16-51). Doses were 0.025 mg/kg/day for children aged > 6 years and 0.032 mg/kg/day for those aged < 6 years.

RESULTS

Volumetric MRI measurements showed a reduction of 2.9-33% at 1 year after treatment initiation, with maximal reductions of 44% and 49% in two patients, at 44 and 36 months, respectively. No change in visual function was recorded during treatment. One child reported decreased orbital pain after 2 weeks; and another, with involvement of the masseters, had increased ability to chew food. Toxicities were mostly to skin and nails, grades 1-2.

CONCLUSIONS

Trametinib can decrease tumor size in some young children with orbital PNF and may prevent progressive disfigurement.

The recurrent plexiform neurofibroma of the scalp in neurofibromatosis type 1: illustrative case

BACKGROUND

Plexiform neurofibroma is a benign tumor of the peripheral nerves. It is an unusual variant of neurofibroma originating from all parts of the nerve. Plexiform neurofibroma is primarily pathognomonic and exhibits an unusual variant from neurofibromatosis type 1 (NF1). The possibility of malignancy and recurrence are the main reasons for long-term, close follow-up.

OBSERVATIONS

The authors report a case of a 14-year-old girl with a recurrent plexiform neurofibroma derived from the peripheral nerves, which also presented with a typical sign of NF1 disease. The aim of the tumor resection is symptomatic relief.

LESSONS

Accomplishing a good outcome can be related to good perioperative planning and a precise operative procedure. The result of anatomical pathology determines the prognosis of the patient. Clinical examination and radiological studies are needed to evaluate the recurrence of complications after surgical procedures.