Distribution of diffuse plexiform neurofibroma on the body surface in patients with neurofibromatosis 1

Association of plexiform and diffuse neurofibromas with malignant peripheral nerve sheath tumor in NF I patients: a whole-body MRI assessment

OBJECTIVE

The aim of this study is to evaluate neurofibromatosis type 1 (NF1) patients with whole-body MRI (WBMRI) to investigate the frequency of plexiform neurofibromas (pNFs), diffuse neurofibromas (dNFs), and malignant peripheral nerve sheath tumors (MPNSTs).

MATERIALS AND METHODS

In this retrospective cross-sectional study, between the years 2015 and 2023, 83 consecutive patients with known NF1 underwent a total of 110 WBMRI screenings for MPNST using a standardized institutional protocol. The lesions are categorized as discrete lesions, pNFs, dNFs, and MPNSTs. Histopathology served as the reference standard for all MPNSTs.

RESULTS

Among the 83 patients analyzed, 53 (64%) were women and 30 were men (36%) of ages 36.94±14.43 years (range, 15-66 years). Of the 83 patients, 33 have a positive family history of NF1 and positive genetic studies. Seven of 83 (8%) have only dNF, 20/83 (24%) have pNF, 28/83 (34%) have both dNF and pNF, and 28/83 (34%) have neither. Of the 83 patients, eight (9.6%) were diagnosed with nine total MPNSTs. Age range for patients with MPNSTs at time of diagnosis was 22-51, with an average age of 33.4 years. Only one MPNST (11%) developed from underlying pNF 4 years after WBMRI along the right bronchial tree. Three of eight (37.5%) patients with MPNST died within 5 years of pathologic diagnosis.

CONCLUSION

This study suggests the absence of a predisposition for development of MPNST from pNFs and dNFs in the setting of NF1. As such, these lesions may not need special surveillance compared to discrete peripheral nerve sheath tumors.

Use of the subfascial plane in debulking an extensive lower extremity plexiform neurofibroma: A case report

INTRODUCTION

Plexiform neurofibromas (PNs) are characterized by their diffuse masses with tortuous expansion along nerve branches. While surgery is the primary management for PNs, the optimal surgical approach remains unestablished.

CASE PRESENTATION

A 35-year-old lady presented with a large hanging mass covering the medial aspect of the thigh and the leg. It caused discomfort, disfigurement, and occasional pain. The patient was planned for the debulking surgery under spinal anesthesia. Incisions were given on the normal-looking skin adjacent to the mass, through the skin layers, subcutaneous tissue and deep fascia until the muscles were seen. The mass was then approached and elevated in the subfascial plane (relatively avascular). Large, dilated, dense tortuous vessels could be seen in the suprafascial and subcutaneous planes. Maximum area that could be removed was marked and excised. The normal contour of the left lower extremity was restored close to achieving a thigh and a leg lift.

DISCUSSION

PNs pose surgical challenges due to their vascularity and difficult locations. The subfascial debulking approach presented in the case aims to reduce intraoperative hemorrhage by avoiding highly vascular areas and preventing entry into blood sinuses within the neurofibromatous tissue. This technique also minimizes the risk of inadvertent injury to nearby neurovascular structures.

CONCLUSION

The proposed subfascial approach, significantly reduces intraoperative hemorrhage during the debulking of a PN.

Neurofibromatosis type 1-associated plexiform neurofibromas of the neck: topography of lesions and surgical treatment data of 69 patients

PURPOSE

Plexiform neurofibromas (PNF) are rare tumors arising from peripheral nerve sheath cells. PNF are a hallmark in patients with neurofibromatosis type 1 (NF1), a tumor predisposition syndrome. PNF often grow invasively and destructively, what may complicate surgical treatment. Data on frequency, location, and surgical procedures of patients with NF1-associated FPNF are scarce. This study provides treatment data of NF1 patients.

METHODS

Localization and treatment data of 69 NF1 patients with neck PNF were analyzed. Frequency of lesions was recorded in coded colors on schematic neck drawings.

RESULTS

The tumors showed no side preference, were located in the entire area under investigation, and did not respect anatomical units/dermatomes. However, the sternocleidomastoid region was particularly frequently affected. The mean number of surgical measures per patient was 1.33. Complications were extensive swelling, hematoma, and bleeding. Histological assessment usually confirmed the clinical assessment of neoplasm. However, histologic differentiation of PNST reveals differences in between tumors that have been unified in clinical assessment as PNF.

CONCLUSION

The color-coded, schematic overview of the frequency distribution of surgical neck interventions in NF1 patients with PNF proved a useful tool to gain assessment of preferred treatment needs. The imaging procedure may be suitable for controlling the external aspect of natural tumor development (growth, effects of aging) in the same way as the documentation of the post-surgical course. Treatment plans for patients with these tumors should consider that repeated interventions may be necessary to achieve a longer-term stable result.

Neurofibromatosis Type 1-Associated Plexiform Neurofibromas of the Face and Adjacent Head Regions: Topography of Lesions and Surgical Treatment Data of 179 Patients

Introduction

Facial plexiform neurofibromas (FPNF) are rare tumors frequently diagnosed in patients with neurofibromatosis type 1 (NF1), a tumor predisposition syndrome. FPNF often grows invasively and destructively, which may complicate surgical treatment. Data on the frequency, location, and surgical procedures of patients with NF1-associated FPNF are scarce. This study provides treatment data from a nationally networked reference center for the treatment of NF1 patients.

Material and Methods

The localization and treatment data of 179 NF1 patients with FPNF were analyzed. Photographically documented tumors of the study area, further determined by imaging, were manually transferred to a facial scheme and digitized. The digitized registrations of the facial extensions of the tumors of each patient were overlaid in a single image (Photoshop™), so that the file of the facial scheme contained the sum of the tumor localization. Finally, the frequency of tumor localization was indicated with a color code. The frequency of tumor extension-related coded colors was applied to outline the lesions' topography on schematic face drawings (heat map).

Results

The distribution of the tumors showed no side preference. The need for the treatment of patients with orbital/periorbital manifestations became evident in the graphic representations. Tumors do not respect anatomical units. However, the classification of the face according to dermatomes, especially the trigeminal nerve, offers indications of tumor spread and guides treatment planning. The mean number of surgical measures per patient was 2.21 (median: 1). Extensive swelling, hematoma, and delayed wound healing were all common postoperative complications.

Conclusion

The color-coded, schematic overview of the frequency distribution of cutaneous tumor spread in NF1 patients with FPNF illustrates the importance of orbital/periorbital and cheek tumor manifestations in patients' treatment needs. The imaging procedure is suitable for controlling natural tumor growth in the same way as the documentation of the post-surgical course. Repeated interventions in the region are included in surgical planning of the progressing tumor disease.

Neurofibromatosis 1 (von Recklinghausen Disease)

Neurofibromatosis 1 (NF1), also known as von Recklinghausen disease, is one of the most common neurocutaneous genetic disorders. Loss of function of the NF1 gene results in overactivation of the RAS/MAPK pathway, leading to neurocutaneous manifestations and osseous abnormalities. Because of medical progress, molecular testing for NF1 after genetic counseling is now available in Japan. In addition, revised diagnostic criteria for NF1 were proposed by NF1 experts of an international panel in 2021. Because the overall degree of severity and manifestations in each patient are not predictable, age-specific annual monitoring and patient education by a multidisciplinary team are important for the management of NF1. Although treatment of plexiform neurofibroma has been challenging, selumetinib (an oral selective MEK1/2 inhibitor), which targets a pathway downstream of RAS, was approved in 2022 for use in children with inoperable, symptomatic plexiform neurofibromas in Japan. This article summarizes recent progress in diagnosis, clinical characteristics, and treatment of various manifestations of NF1 and proposes the future direction required to resolve unmet needs in patients with NF1 in Japan.

Health-related quality of life in patients with neurofibromatosis 1 in Japan: A questionnaire survey using EQ-5D-5L

Neurofibromatosis 1 (NF1) is a genetic disorder characterized by various symptoms including dermatological, neurological, and osseous manifestations. These complications often cause cosmetic or functional disturbances, resulting in a significant impact on quality of life (QOL). However, there are limited data on QOL of individuals with NF1 in Japan. Therefore, we studied health-related QOL in patients with NF1 compared with that in general populations and the association with severity grade using EQ-5D. A cross-sectional study was conducted for 73 adult NF1 patients (26 males and 47 females; mean age, 44.16 years). The EQ-5D-5L values and visual analog scale (VAS) in patients with NF1 were 0.738 ± 0.137 and 69.93 ± 19.14, respectively. Both scores were significantly lower in patients with NF1 than in healthy volunteers (p < 0.0001). The score for anxiety/depression was the highest among the five items of EQ-5D. Although we investigated differences in the index value and VAS between stage 2 or less and stage 3 or higher, there was no difference in the scores between groups related to certification criteria for the public medical expenses subsidy system. EQ-5D-5L is a valuable assessment tool for health-related QOL in patients with NF1, but it might not be sufficient for severity certification of NF1 in Japan. We would need the revision of the current certification based on the patients' demand in the future. Our findings might be useful for assessment of therapeutic effects and appropriate resource allocation in the care of patients with NF1.

New-onset cutaneous nodule arising from hypertrichotic brownish patch in a 6-year-old girl

A 6-year-old girl presented with an enlarging asymptomatic nodule within a hyperpigmented hypertrichotic patch on her left thigh. Histopathological examination revealed tumour cells with round to fusiform nuclei in a fine fibrillary collagenous stroma, along with increased cellularity. Most of the tumour cells were positive for S-100 and negative for HMB-45 and Melan-A.

Imaging appearance of isolated diffuse neurofibroma of nipple areolar area: a case report

Sporadic neurofibromas of the nipple-areolar complexes are exceptional even in patients with neurofibromatosis. Diffuse neurofibroma is an uncommon subtype of neurofibroma that has received little attention in the imaging literature. As are most superficial lesions, it is often evaluated clinically and if biopsy is needed, it is usually performed without imaging. However the imaging data is quite characteristic with the aim of evaluating the extension in depth and detecting an underlying cancer. We report a case of women without a history of neurofibromatosis presenting a skin thickening disfiguring her left breast, related to diffuse neurofibroma of the nipple-areolar complexes confirmed histologically. We study echo-mammography and breast magnetic resonance imaging (MRI) findings in order to highlight its radiographics features.

New FDA oncology small molecule drugs approvals in 2020: Mechanism of action and clinical applications

In 2020, fifty-three new drugs, including forty small-molecules (thirty-six new chemical entities and four new diagnostic agents) and thirteen biologic drugs were approved by the U.S. Food and Drug Administration (FDA). This year, small-molecules continue to play a role in innovative treatments representing around 75% of all drugs accepted by FDA. The dominant therapeutic area was oncology, accounting for twenty-three new approvals, including thirteen new chemical entities, four new diagnostic agents, and thirteen biologic drugs. Recognizing the importance of small-molecules on cancer treatment, this review aims to provide an overview regarding the clinical applications and mechanism of action of the thirteen new small-molecules (excluding new diagnostic agents) approved by FDA in 2020.

Diffuse neurofibroma of the chest and abdominal wall invading the diaphragm leads to diaphragmatic eventration: case report

Background

Neurofibromatosis type 1 (NF1) is an autosomal dominant condition with a high rate of new mutation and variable expression. Diffuse neurofibroma of the epidermis invading deeper organs is rare.We report a case of diffuse subcutaneous neurofibroma in the thoracoabdominal wall which had invaded the diaphragm and caused diaphragmatic eventration.

Case presentation

We describe a patient with diffuse neurofibroma of the chest and abdomen who was admitted to the hospital due to sudden abdominal pain and a possible diaphragmatic hernia. We performed thoracotomy and found that the neurofibroma had invaded the diaphragm and caused diaphragmatic eventration.

Conclusions

This occurrence has not been reported, and it shows that although neurofibromatosis is a benign disease, it still has the biological behavior of a malignant tumor and may cause a serious impact on and damage to other organs.

Increased nuclear translation of YAP might act as a potential therapeutic target for NF1-related plexiform neurofibroma

Plexiform neurofibroma (pNF) in the head and neck is a characteristic feature in patients with neurofibromatosis type 1 (NF1) and is associated with significant disfigurement and psychological distress. Yes-associated protein (YAP), the key molecule involved in the Hippo pathway, is a vital transductor that regulates the proliferation and remyelinating of Schwann cells. The functional status of YAP and its feasibility as a potential target are still unknown in pNF. A total of 17 pNF tumor tissue specimens from the head and neck were collected at the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine. Histologically, diagnosis of the Schwann cell region in pNF was achieved with hematoxylin-eosin staining, positive reactions for S100, SOX10, ERK and p-ERK, and low identification of Ki67 and SMA. Compared with normal nerve tissue, obviously increased nuclear YAP was detected in the Schwann cell region of pNF, with a mean nuclear staining rate of 67.11%. Based on the shNF1 Schwann cell model (the RSC96 cell line), with upregulated expression of RAS, ERK and p-ERK, p-YAP (Ser127) and p-YAP (Ser397) were significantly decreased and total YAP and nuclear YAP were increased. According to a confocal assay, the interference of shNF1 substantially promoted YAP nuclear translocation. Compared with control Schwann cells, the YAP inhibitor CA3 might have a more sensitive effect (IC₅₀: NC=0.96±0.04, shNF1=0.71±0.02, P<0.05) on the shNF1 Schwann cell model than the classic MEK1/2 inhibitor selumetinib (IC₅₀: NC=14.36±0.95, shNF1=24.83±0.98, P>0.05). For in vivo inhibition, the CA3 group and the selumetinib group displayed a similar inhibition effect with no significant difference. Increased nuclear translation and the functional state of YAP implies that the YAP-Hippo pathway might play an important role in the formation and remyelination of pNF. Compared with selumetinib, the YAP inhibitor can exhibit a similar but more sensitive effect on NF1^-/- Schwann cells. These observations imply that YAP as a novel or adjuvant therapy target in the treatment of pNF.

Primary Intrabulbar Neurofibroma

PURPOSE

Eye globe enucleation due to other than a malignant tumor is very rare today. Solitary intraocular neurofibroma without other signs of neurofibromatosis is a rare benign tumor and few cases have been reported to date.

MATERIAL AND METHODS

In 10 year interval from Jan 1 2007 to Dec 31 2016 we analyzed non-malignant eye globe enucleations.

RESULTS

Of the 49 enucleated blind eyes, each patient had visual acuity with no light perception, 34 (69.4%) were indicated for enucleation due to complications following previous postoperative surgery after trauma, 14 patients (28.6%) were due to secondary glaucoma and other complications following previous intraocular surgery, and in one patient (2%) the primary isolated intraocular neurofibroma was verified after enucleation.

CASE REPORT

A patient with isolated intrabulbar neurofibroma has been monitored since childhood for intraocular lesion and histologically verified at adult age. At the time of enucleation, he was 25 years old, squint since childhood and was observed for hamartoma in his right eye since he was 13 years old. Due to the progression of intrabulbar lesion, loss of visual acuity (functional state - no light perception) and secondary glaucoma, the right eye globe was enucleated at adult age and histopathological examination confirmed intraocular neurofibroma in the absence of neurofibromatosis.

CONCLUSION

Every enucleated eye globe should be subjected to a thorough histopathological examination. Isolated intraocular neurofibromas can occur as isolated orbital or intrabulbar masses without systemic features.