Malignant peripheral nerve sheath tumours of the pericardium in a patient with Neurofibromatosis type 1: The diagnostic value of 18F-FDG PET-CT and I-123 MIBG SPECT-CT

Risk factors for intraoperative hemorrhage of Type I neurofibromatosis

INTRODUCTION

Neurofibromatosis (NF) is an inherited disease and a benign tumor originating from nerve sheath cells. Neurofibromatosis type I (NF1) is the most common type, and most cases are characterized by neurofibromas. Neurofibromas in NF1 are mainly treated by surgery. Our study explores the risk factors for intraoperative hemorrhage in Type I neurofibromatosis patients who underwent neurofibroma resection.

METHODS

A cross-sectional comparison of the patients who had undergone resection of neurofibroma for NF1. Data regarding patient characteristics and data about operative outcomes were recorded. The definition of intraoperative hemorrhage group was the intraoperative blood loss greater than 200 ml.

RESULTS

Of 94 eligible patients, 44 patients were in the hemorrhage group and 50 patients were in the non-hemorrhage group. Multiple logistic regression analysis demonstrated that the area of excision, classification, surgical site, primary surgical, and organ deformation were significant independent predictors of hemorrhage.

CONCLUSION

Early treatment can reduce the tumor cross-sectional area, avoid organ deformation, and reduce intraoperative blood loss. For plexiform neurofibroma or neurofibroma of the head and face, the amount of blood loss should be predicted correctly, and preoperative evaluation and blood preparation should be paid more attention to.

Mechanisms underlying synergy between DNA topoisomerase I-targeted drugs and mTOR kinase inhibitors in NF1-associated malignant peripheral nerve sheath tumors

Malignant peripheral nerve sheath tumors (MPNSTs) are soft-tissue sarcomas that frequently arise in patients with neurofibromatosis type 1 (NF1). Most of these tumors are unresectable at diagnosis and minimally responsive to conventional treatment, lending urgency to the identification of new pathway dependencies and drugs with potent antitumor activities. We therefore examined a series of candidate agents for their ability to induce apoptosis in MPNST cells arising in nf1/tp53-deficient zebrafish. In this study, we found that DNA topoisomerase I-targeted drugs and mTOR kinase inhibitors were the most effective single agents in eliminating MPNST cells without prohibitive toxicity. In addition, three members of these classes of drugs, either AZD2014 or INK128 in combination with irinotecan, acted synergistically to induce apoptosis both in vitro and in vivo. In mechanistic studies, irinotecan not only induces apoptosis by eliciting a DNA damage response, but also acts synergistically with AZD2014 to potentiate the hypophosphorylation of 4E-BP1, a downstream target of mTORC1. Profound hypophosphorylation of 4E-BP1 induced by this drug combination causes an arrest of protein synthesis, which potently induces tumor cell apoptosis. Our findings provide a compelling rationale for further in vivo evaluation of the combination of DNA topoisomerase I-targeted drugs and mTOR kinase inhibitors against these aggressive nerve sheath tumors.

Neurofibromatosis type I with malignant peripheral nerve sheath tumors in the upper arm: A case report

RATIONALE

Malignant peripheral nerve sheath tumor occurring in the context of neurofibromatosis type I (NF1) is relatively rare. Herein, we report a case of NF1 with malignant peripheral nerve sheath tumor in the upper arm.

PATIENT CONCERNS

A 24-year-old man presented with a mass in the medial part of the left upper arm that had been present for more than 20 years. In the previous 1 year prior to admission, the mass had grown significantly. Physical examination showed cafe-au-lait spots of variable sizes throughout the body and multiple masses in the medial part of the left upper arm. Three months later after the resection of the masses, the patient was readmitted to our department due to tumor recurrence. Two months after the extended resection, in situ recurrence of the tumor was noted again. Four months after the operation and the administration of radiotherapy, a mass was found in the outside of the left upper arm.

DIAGNOSIS

Immunohistochemical staining showed the masses were positivity for vimentin, CD34, and S100; the tumor cells were negative for PGP9.5, CD57, EMA, and SMA. The Ki-67 labeling index was approximately 40%. A diagnosis of malignant peripheral nerve sheath tumor was made.

INTERVENTIONS

Surgical resection was performed for both the primary tumors and the 2 subsequent recurrence tumors. The patient underwent radiotherapy with 60 Gy in 30 fractions after the third operation. Four months after the administration of radiotherapy, the patient underwent tumorectomy of a mass in the outside of the left upper arm.

OUTCOMES

During the 4-month follow-up after the fourth operation, the patient's condition was stable.

LESSONS

Malignant peripheral nerve sheath tumor in NF1 is an exceedingly rare entity that poses a great diagnostic challenge. High-frequency ultrasound can support the diagnosis.