Recurrent malignant peripheral nerve sheath tumor presenting as an asymptomatic intravenous thrombus extending to the heart: a case report

Background Malignant peripheral nerve sheath tumor (MPNST) is a rare soft tissue sarcoma mainly treated via surgical resection. Herein, we report a case of MPNST wherein a massive tumor thrombus extended to the major veins and heart. Case presentation A 39-year-old female with a history of neurofibromatosis type 1 developed MPNST from the right radial nerve. In addition to adjuvant chemotherapy, she underwent wide tumor resection and concomitant radial nerve resection, followed by postoperative radiotherapy. Histological evaluation revealed marked venous invasion. The 2-year follow-up CT revealed an asymptomatic recurrent tumor thrombus extending from the right subclavian vein to the heart. An urgent life-saving operation was performed to ligate the base of the right subclavian vein and remove the entire intravenous thrombus that extended to the right ventricle. The remaining tumor in the right subclavian vein increased in size 3 months after thrombectomy. After confirming the absence of any metastatic lesions, the patient underwent extended forequarter amputation to achieve surgical remission. One year later, a new metastasis to the right diaphragm was safely resected. The patient remains alive without any evidence of disease 2 years after the extended forequarter amputation. Conclusions In cases of a previous history of microscopic venous invasion, recurrence can occur as a massive tumor thrombus that extends to the great vessels.

RT-5 Boron Neutron Capture Therapy has extended progression-free survival about recurrent malignant peripheral nerve sheath tumor - A case report

Introduction: Recurrent malignant peripheral nerve sheath tumor (MPNST) is intractable. Boron neutron capture therapy (BNCT) is a treatment using tumor-selective particle radiation, and is indicated for medical treatment for head and neck cancer, and also used for malignant glioma and malignant meningioma.<Case>20-year-old woman who has MPNST that extends from the subcutaneous tissue of the right neck to the posterior fossa. <Medical History>Chemotherapy and local irradiation(50.4Gy/28fr) for primary embryonal rhabdomyosarcoma of the right ear canal at the age six.<Current medical history>Right cervical tumor developed at 17-year-old, some chemotherapy regimens and tumor resections were performed as recurrence of rhabdomyosarcoma at the previous hospital. After she was diagnosed with MPNST in the pathology consultation at our hospital, she was irradiated with heavy ion beam 70.8Gy(RBE)/16fr and received additional chemotherapies at our department, but her tumor was refractory. Although BNCT for MPNST is not covered by health insurance in Japan, she wanted to try to be treated for BNCT. After confirming boron accumulation in the tumor (SUVmax 4.28) by FBPA-PET, tumor growth and hydrocephalus occurred while waiting for travel to Taiwan due to the spread of COVID-19 infection. She was performed tumor resection(NTR) and irradiated with SRS 20Gy/fr for the residual lesion, but tumor had a rapid recurrence from the margin of the excision cavity. Finally, she could travel about 3 months after the operation and underwent BNCT, that used neutrons and 10B-boronophenylalanine from the Tsinghua University research reactor in Taiwan. No serious adverse events including cerebral edema were observed, and dramatic tumor shrinkage was maintained after treatment. FBPA-PET of 3 months later showed accumulation in the part of the margin of the cavity, the recurrence was observed on MRI after 3 and a half months. Discussion: BNCT for refractory/recurrent MPNST showed acceptable safety and was able to prolong progression-free survival.

Rare hand mass: malignant peripheral nerve sheath tumor

.

Case report of malignant peripheral nerve sheath tumor of parotid in a patient with neurofibromatosis type 1

<p>Malignant peripheral nerve sheath tumor (MPNST) refers to spindle cell sarcomas arising from or separating in the direction of cells of the peripheral nerve sheath. The MPNST of the parotid gland is an extremely rare tumor, accounts for &lt;5% of all soft tissue sarcomas, and carries a poor prognosis. Diagnosis of MPNSTs is usually based on histopathology aided by IHC, which reflects the Schwann cell differentiation in this neoplasm. Approximately 50-90% of MPNSTs are positive for S-100 protein. A 56-year-old male presented with right parotid swelling for 3 months and incomplete right eye closure. The patient was diagnosed with neurofibromatosis 1 (NF-1) and pulmonary tuberculosis in the past. On Examination, a hard, tender swelling measuring 5×4 cm involving the right parotid gland and right grade 2 LMN facial palsy was noted. Histopathology was suggestive of a MPNST.</p><p><strong> </strong></p>