Establishment and characterization of a recurrent malignant peripheral nerve sheath tumor cell line: RsNF

Malignant peripheral nerve sheath tumor (MPNST) is a highly aggressive and recurrent soft tissue sarcoma. It most commonly occurs secondary to neurofibromatosis type I, and it has a 5-year survival rate of only 8-13%. To better study the tumor heterogeneity of MPNST and to develop diverse treatment options, more tumor-derived cell lines are needed to obtain richer biological information. Here, we established a primary cell line of relapsed MPNST RsNF cells derived from a patient diagnosed with NF1 and detected the presence of NF1 mutations and SUZ12 somatic mutations through whole-exome sequencing(WES). Through tumor molecular marker targeted sequencing and single-cell transcriptome sequencing, it was found that chromosome 7 copy number variation (CNV) was gained in this cell line, and ZNF804B, EGFR, etc., were overexpressed on chromosome 7. Therefore, RsNF cells can be used as a useful tool in NF1-associated MPNST genomic amplification studies and to develop new therapeutic strategies.

Ovarian epithelioid malignant peripheral nerve sheath tumor with EWSR1-CREM fusion: A case report and literature review

Epithelioid malignant peripheral nerve sheath tumor (EMPNST) is a rare soft tissue sarcoma. The authors report the first case of EMPNST arising in the ovary (OEMPNST). A 7-year-old child underwent left salpingo-oophorectomy due to tumor rupture and the pathology suggested a juvenile granulosa cell tumor (JGCT). Six cycles of bleomycin, etoposide, and carboplatin were administrated. A second surgery was applied due to relapse 4 months after the last cycle of chemotherapy, and the pathology revealed JGCT with extensive abdominopelvic seedings even after interinstitutional consultation in two hospitals. Next-generation sequencing demonstrated EWSR1 exon12-CREM exon6 fusion with neurofibromatosis-2 gene deletion, and no mutation was detected in either FOXL2 or DICER1. However, pathology consultation in two other hospitals suggested the diagnosis of OEMPNST, and additional immunohistochemical (IHC) staining revealed positive H3K27me3. Nonetheless, she was treated with nine courses of chemotherapy but experienced a second recurrence of extensive abdominal metastases approximately 3 months after ceasing chemotherapy. Neither elevated tumor makers nor abnormal sex hormones level was noted since the initial presentation. Repeated cytoreductive surgery was conducted and IHC staining showed expression of SOX10, S-100, INI-1, and α-inhibin in tumor tissue. A final diagnosis of OEMPNST with EWSR1-CREM fusion was established, indicating that the probability of OEMPNST could not be excluded when treatment for JGCT showed poor response. A comprehensive evaluation including biological characteristics, morphology, IHC staining, and molecular features is vital in the differential diagnosis between JGCT and OEMPNST.

RRM2 as a novel prognostic and therapeutic target of NF1-associated MPNST

BACKGROUND

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive sarcomas that typically develop in the setting of neurofibromatosis type 1 (NF1) and cause significant morbidity. Conventional therapies are often ineffective for MPNSTs. Ribonucleotide reductase subunit M2 (RRM2) is involved in DNA synthesis and repair, and is overexpressed in multiple cancers. However, its role in NF1-associated MPNSTs remains unknown. Our objective was to determine the therapeutic and prognostic potential of RRM2 in NF1-associated MPNSTs.

METHODS

Identification of hub genes was performed by using NF1-associated MPNST microarray datasets. We detected RRM2 expression by immunochemical staining in an MPNST tissue microarray, and assessed the clinical and prognostic significance of RRM2 in an MPNST cohort. RRM2 knockdown and the RRM2 inhibitor Triapine were used to assess cell proliferation and apoptosis in NF1-associated MPNST cells in vitro and in vivo. The underlying mechanism of RRM2 in NF1-associated MPNST was revealed by transcriptome analysis.

RESULTS

RRM2 is a key hub gene and its expression is significantly elevated in NF1-associated MPNST. We revealed that high RRM2 expression accounted for a larger proportion of NF1-associated MPNSTs and confirmed the correlation of high RRM2 expression with poor overall survival. Knockdown of RRM2 inhibited NF1-associated MPNST cell proliferation and promoted apoptosis and S-phase arrest. The RRM2 inhibitor Triapine displayed dose-dependent inhibitory effects in vitro and induced significant tumor growth reduction in vivo in NF1-associated MPNST. Analysis of transcriptomic changes induced by RRM2 knockdown revealed suppression of the AKT-mTOR signaling pathway. Overexpression of RRM2 activates the AKT pathway to promote NF1-associated MPNST cell proliferation.

CONCLUSIONS

RRM2 expression is significantly elevated in NF1-associated MPNST and that high RRM2 expression correlates with poorer outcomes. RRM2 acts as an integral part in the promotion of NF1-associated MPNST cell proliferation via the AKT-mTOR signaling pathway. Inhibition of RRM2 may be a promising therapeutic strategy for NF1-associated MPNST.

Cardiac malignant peripheral nerve sheath tumor on computed tomography and magnetic resonance imaging: A case report

RATIONALE

Malignant peripheral nerve sheath tumor (MPNST) is a very rare sarcoma of the heart, and few cases have been reported. Herein, we retrospectively reviewed clinical manifestations, imaging features and management of our patient and other reported cases.

PATIENT CONCERNS

A 32-year-old woman was referred to the emergency department of our institution with expiratory dyspnea, edema of face for a month.

DIAGNOSIS

The patient was initially diagnosed with asthma at a local hospital based on a history of fatigue, cough and expiratory dyspnea, as well as negative electroencephalogram (ECG) and chest radiography. Based on computed tomography (CT) and cardiac magnetic resonance imaging (CMRI) in our hospital, she was found to have a malignant tumor involving right atrium. The tumor was diagnosed as MPNST according to histopathological results.

INTERVENTIONS

The tumor was deemed unresectable during the surgery. Then, the patient was referred for chemotherapy and radiotherapy.

OUTCOMES

The patient deteriorated and died 4 months later.

LESSONS

Cardiac MPNST is very uncommon with nonspecific clinical and imaging characteristics according to limited cased reported. CMR, due to the high tissue resolution and multiple sequence imaging advantages, is useful for the detection, location and evaluation whether there is involvement of adjacent structures, and may help better clinical decision-making.

Epidemiological Analysis of Major Complications Requiring Medical Intervention in Patients with Neurofibromatosis 1

Neurofibromatosis 1 has various complications. To elucidate the frequency of neurofibromatosis 1-related major complications requiring medical intervention, a nationwide retrospective study was conducted of 3,530 patients with neurofibromatosis 1 registered from 2001 to 2014 in Japan. The ratio of certified patients requiring medical intervention (>stage 3) was 82%. Patients classified in the most severe grade experienced dermatological complications (71.8% of patients), neurological complications (38.1%) and bone complications (33.3%). In patients with dermatological manifestations, medical treatment was needed for cutaneous neurofibromas (58%), diffuse plexiform neurofibromas (31%) and malignant peripheral nerve sheath tumours (10%). Patients with neurological manifestations needed medical treatment mainly for brain tumours (53%) and intellectual disability (26%). Patients with bone manifestations needed medical treatment for pseudoarthrosis (9%), scoliosis (55%) and bone defects (16%). It is necessary for physicians to be aware of neurofibromatosis 1-related complications requiring medical intervention in order to provide appropriate care for patients with neurofibromatosis 1.

Diagnosis, Classification, and Management of Soft Tissue Sarcomas

BACKGROUND

Soft tissue sarcomas are challenging to oncologists due to their unique character, the infrequency of their occurrence, and the difficulties in predicting outcomes. Advances in imaging, as well as improvements in surgical techniques and adjunctive treatment methods, have improved care for patients with these unusual disorders.

METHODS

The various types of soft tissue tumors are defined, and the statistics for the Orthopaedic Oncology Group in relation to them are reviewed and compared with literature references.

RESULTS

The overall survival rate for 1,220 tumors treated at our institute from June 1972 to June of 2001 was 72%, with a wide range. Patients with leiomyosarcomas, clear cell sarcomas, and malignant fibrous histiocytomas had a poorer survival rate, while those with fibrosarcomas, liposarcomas, and neurofibrosarcomas fared better. Outcome was affected by patient age, tumor anatomic site, tumor stage, and a history of recurrence.

CONCLUSIONS

Competent imaging, predictive immunological and genetic studies, improved surgery, and newer methods of adjunctive and neoadjunctive treatment should result in improvements in outcomes for patients with these tumors.

Soft-tissue sarcomas in children and adolescents with neurofibromatosis type 1

BACKGROUND

Patients affected by neurofibromatosis type 1 (NF1) are at higher risk of developing soft-tissue sarcomas (STS) than the general population. The clinical findings and outcome in 43 children and adolescents with NF1 treated for STS in the Italian protocols between 1988 and 2004 are reported.

METHODS

The study included 37 patients with neurogenic sarcomas (36 malignant peripheral nerve sheath tumors [MPNST], 1 triton tumor) and 6 cases of rhabdomyosarcoma (RMS). The prevalence of NF1 observed during the study period was 43% in the MPNST population and 1% in the RMS group.

RESULTS

Most patients with neurogenic sarcomas had large, invasive tumors. Five-year event-free and overall survival rates were 19% and 28%, respectively. Two of 16 patients with evaluable disease responded to chemotherapy. All 6 RMS patients were </=3 years old and had embryonal subtype, 5 of 6 arising in the genitourinary tract or pelvis (paravesical); 4 were alive in first remission at the time of the analysis, 1 was alive in second remission after a local recurrence, and 1 died of disease.

CONCLUSIONS

The occurrence of STS in pediatric patients with NF1 syndrome in Italy is discussed, confirming that NF1 patients have a high risk of developing STS, and particularly MPNST, often with an aggressive clinical presentation and poor outcome. Cases of RMS tended to have particular features (early age, embryonal histotype, genitourinary site) and their outcome seemed to resemble that of the general RMS population.

Pediatric neurofibrosarcoma

BACKGROUND/PURPOSE

Neurofibrosarcoma is rare in children, and the natural history and prognostic factors are not well described. The authors present a 57-year review of their experience.

METHODS

The charts of children with neurofibrosarcoma were reviewed retrospectively. Statistical analysis was performed using the Chi2 and unpaired t tests.

RESULTS

From 1944 to 2001, 38 patients under the age of 21 were diagnosed with neurofibrosarcoma. Twenty-two were boys. The average age at diagnosis was 13.8 years (range, 3 to 19.9 years). Nineteen patients (50%) had neurofibromatosis. The tumor site was as follows: extremity, 19 patients; trunk, 9 patients; head and neck, 7 patients; and retroperitoneum, 3 patients. The average tumor size was 10 cm. The margins after resection were as follows: grossly positive, 9; microscopically positive, 5; negative, 21; and unknown, 3. Patients with positive margins had a 22% survival rate, whereas those with negative or unknown margins had a 34% survival rate. Thirty-two patients achieved a complete response, 2 a partial response, and 4 progressed while on therapy. Twenty-six patients relapsed after a complete response (11 local, 10 distant, 5 both). Of the 15 patients with a distant relapse, 73% (11) relapsed in the lung. Twelve (32%) patients survived with an average follow-up of 14 years (range, 0.3 to 28 years). Nine patients were treated with chemotherapy, 9 with radiation, and 9 with both chemotherapy and radiation. Outcome was not significantly affected by gender, presence of neurofibromatosis, site, margin, or use of adjuvant therapy.

CONCLUSION

Neurofibrosarcoma remains a rare disease in children with insufficient contemporary numbers to assess efficacy of therapy. Prognosis remains poor with a high incidence of relapse, particularly in the lungs, suggesting that more aggressive therapies to control both local and distant relapses are needed.

PET-FDG en paciente con enfermedad de Von Recklinghausen y neurofibrosarcoma dorsal izquierdo

The development of neurofibrosarcomas in patients with Von Recklinghausen disease is a rare complication that can appear in the daily clinical practice. We report a clinical case with Von Recklinghausen disease and recurrence of a left dorsal neurofibrosarcoma diagnosed by Positron Emission Tomography with fluorine-18-fluoro-deoxyD-glucose (FDG-PET). We believe this work is important due to the relatively uncommon clinical presentation and the discussion on the utility of 18-FDG PET and other conventional imaging methods in the diagnosis of this entity.

Metastatic spinal neurofibrosarcoma

Neurofibrosarcomas are rare tumors usually arising in somatic soft tissues or peripheral nerves. Four cases of metastatic neurofibrosarcoma to the spine have been reported before. The current case is unusual because of the presence of two distinct, metachronous spinal metastasis and lung metastasis. A 30-year-old woman with neurofibromatosis and a history of previous neurofibrosarcoma resection presented with back pain. Radiologic evaluation revealed a lytic lesion of the eleventh thoracic vertebra. A transthoracal corpectomy, reconstruction by Harms' cage and posterior instrumentation, and fusion were carried out. After the completion of adjuvant chemotherapy, a solitary pulmonary nodule was detected. Shortly after resection of the metastatic pulmonary nodule, the patient complained of acute onset low-back pain. Radiologic assessment revealed another lytic lesion in the L5 vertebra after 6 months. Again, a corpectomy, anterior and posterior instrumentation, and fusion were carried out. Eight months after the second spinal resection, another solitary pulmonary metastasis was diagnosed and resected. The patient's health status suddenly deteriorated 26 months after the initial spinal metastatectomy, and she died. Though local control can be achieved in more than 80% of the patients with neurofibrosarcoma by wide surgical resection followed by adjuvant chemo- and radiotherapy, most patients die of systemic metastasis. The current patient survived 50 months after the initial resection of a forearm neurofibrosarcoma. Despite achieving local control, she died due to systemic recurrence. Prolonged survival with the help of chemo- and radiotherapy justifies our aggressive surgical strategy for the treatment of spinal metastasis in order to achieve neurologic cure and spinal stability.

Periocular neurofibrosarcoma in a horse

A periocular neurofibrosarcoma was debulked and treated with intralesional cisplatin in a 5-year-old Thoroughbred mare. The horse presented with a 1-year history of a large slowly progressing subcutaneous mass over the right supraorbital process. The mass was surgically debulked, and intralesional cisplatin (1.0 mg/cm3) was injected in 3 doses at 2 weeks, 5 weeks, and 8 weeks postoperatively. No recurrence was noted over a 15-month follow-up period. Histopathology of the mass indicated neurofibrosarcoma.

[Neurogenic sarcoma of the vagal nerve]

A rare case of neurogenic sarcoma of the vagal nerve was presented. Ten cases of such location have been described so far. Neurogenic sarcoma derives from supported elements of peripheral nerves. Its development is asymptomatic and usually the first manifestation is the occurrence of the tumour. This kind of disease is local malignant neoplasm, but it can give metastases, and then the prognosis is significantly worse. The modern treatment is radiotherapy with preceding radical dissection.

[Cutaneous and subcutaneous sarcomas]

Cutaneous sarcomas are uncommon tumors presenting many histological types. The diagnosis is based on pathological, immunohistochemical and sometimes ultrastructural studies. The development of cytogenetic and molecular analysis may constitute an additional aid to the diagnosis and classification. Prognosis and therapeutic strategies are established on the basis of various criteria using different types of staging and grading, but these classifications have not yet been standardized. The rarity of cutaneous sarcoma, and the diversity of clinical presentations account for the difficulties of management, which requires a multidisciplinary approach.

[Neurosarcoma associated with neurofibromatosis 1. Apropos of a case and review of the literature]

BACKGROUND

Type 1 neurofibromatosis considerably increases the risk of cancer development, particularly neurosarcoma. We report a case in a patient with chemosensitive metastatic neurosarcoma.

CASE REPORT

A young female patient with familial type 1 neurofibromatosis developed pleural metastasis of a neurosarcoma located on the arm. This tumor was initially highly sensitive to chemotherapy, but relapse occurred.

DISCUSSION

Follow-up in the order members of the family was particularly difficult to organize. One sister developed cerebral astrocytoma. Neurosarcomas develop earlier in patients with type 1 neurofibromatosis, worsening prognosis. We suggest a prospective and structured registration of such cases using a network of clinicians and pathologists in order to improve management schemes.

Malignant change in cutaneous neurofibromas--case reports

Neurofibromatosis is the most common single gene disorder to affect the nervous system, with an estimated incidence of 1 in 3000 live births. Neurofibromatosis (NF) may be classified into von Recklinghausen NF (NFI) and bilateral acoustic NF (NFII) based on the distribution of lesions. The most common lesion associated with the von Recklinghausen type is the neurofibroma. Various complications are associated with neurofibromatosis, the most feared of which is malignant change in the neurofibroma. This article describes the study of 7 cases of proven malignant change in neurofibromas with regards to presentation, clinical progress and treatment followed by a review of the present literature.