Malignant peripheral nerve sheath tumor in children: A single-institute retrospective analysis

Clinical presentation of childhood soft tissue sarcomas: a systematic review and meta-analysis

BACKGROUND

Time to diagnosis (TTD) of childhood soft tissue sarcoma (STS) is significantly associated with survival. This review aims to identify pre-diagnostic symptoms/signs to inform earlier diagnosis interventions.

METHODS

Medline, Embase, Cochrane and Web-of-Science were searched between January 2010 and February 2021 for studies including children (<18 years) diagnosed with STS, with no language restrictions. Pooled proportions of symptoms/signs were calculated and subanalysed by tumour location and age.

RESULTS

Fifty-nine eligible studies were identified, totalling 2462 cases. The most frequent symptoms were lump/swelling (38%, 95% CI 27% to 51%), pain (6%, 95% CI 3% to 10%), cutaneous changes (4%, 95% CI 0 to 9%), localised eye swelling (3%, 95% CI 0 to 7%), cranial nerve deficits (2%, 95% CI 0 to 5%) and constitutional symptoms (2%, 95% CI 0 to 5%).Symptoms varied by location and age. Localised eye swelling (20%, 95% CI 3% to 45%), cranial nerve deficits (14%, 95% CI 4% to 28%) and impaired visual function (6%, 95% CI 0 to 17%) were frequent in head and neck tumours. For abdomen/pelvic tumours, urinary symptoms (24%, 95% CI 5% to 15%), abdominal distension/discomfort (22%, 95% CI 4% to 47%), genital lump/swelling (16%, 95% CI 1% to 42%), constitutional symptoms (9%, 95% CI 0%] to 23%), vaginal bleeding (7%, 95%C I 0 to 21%) and bowel habit changes (6%, 95% CI 0 to 17%) were frequent.In <5 years, consumptive coagulopathy (16%, 95% CI 0 to 48%), cutaneous changes (5%, 95% CI 0 to 40%), genital lump/swelling (4%, 95% CI 0 to 14%), reduced mobility (3%, 95% CI 0 to 11%), vaginal bleeding (2%, 95% CI 0 to 11%) and bleeding/bruising/petechiae (2%, 95% CI 0 to 20%) were frequent compared with lump/swelling, constitutional symptoms, pain and headaches which were frequent among >11 years.

CONCLUSIONS

For STS, pre-diagnostic symptoms differ by age and location, highlighting the need to tailor early diagnosis interventions.

Survival outcomes of malignant peripheral nerve sheath tumors (MPNSTs) with and without neurofibromatosis type I (NF1): a meta-analysis

INTRODUCTION

Malignant peripheral nerve sheath tumors (MPNSTs) are malignancies that demonstrate nerve sheath differentiation in the peripheral nervous system. They can occur sporadically or be associated with neurofibromatosis type 1 (NF1), an autosomal dominant neurocutaneous disorder, with up to 13% of patients developing MPNSTs in their lifetimes. Previous studies have suggested conflicting findings regarding the prognosis of NF1 for patients with MPNSTs. The elucidation of NF1 as an independent prognostic factor on mortality has implications for clinical management. We aim to investigate the role of NF1 status as an independent prognostic factor of overall survival (OS) and disease-specific survival (DSS) in MPNSTs.

METHODS

An electronic literature search of PubMed and MEDLINE was performed on studies reporting OS or DSS outcomes of MPNSTs with and without NF1. A grey literature search by reviewing bibliographies of included studies and review articles was performed to find pertinent studies. Data was extracted and assessed in accordance with the PRISMA guidelines. A meta-analysis was performed to calculate hazard ratios (HRs) using a random-effects model. The primary and secondary outcomes were all-cause and disease-specific mortality, respectively, with NF1 as an independent prognostic factor of interest.

RESULTS

A total of 59 retrospective studies involving 3602 patients fulfilled the inclusion criteria for OS analysis, and 23 studies involving 704 MPNST patients were included to evaluate DSS outcomes. There was a significant increase in the hazard of all-cause mortality (HR 1.63, 95% CI 1.45 to 1.84) and disease-specific mortality (HR 1.52, 95% CI 1.24 to 1.88) among NF1 as compared to sporadic cases. Subgroup analyses and meta-regression showed that this result was consistent regardless of the quality of the study and year of publication.

CONCLUSION

NF1 is associated with a substantially higher risk of all-cause and disease-specific mortality. This finding suggests that closer surveillance is required for NF1 patients at risk of developing MPNSTs.

Malignant peripheral nerve sheath tumor in children: A clinicopathologic and molecular study with parallels to the adult counterpart

Malignant peripheral nerve sheath tumors (MPNST) are aggressive neoplasms, arising either sporadically, in the setting of neurofibromatosis type I (NF1) or post radiation. Most MPNST occur in adults and their pathogenesis is driven by the loss of function mutations in the PRC2 complex, regardless of their clinical presentation. In contrast, pediatric MPNST are rare and their pathogenesis has not been elucidated. In this study, we investigate a large cohort of 64 MPNSTs arising in children and young adults (younger than the age of 20 years) to better define their clinicopathologic and molecular features. Sixteen (25%) cases were investigated by MSK-IMPACT, a targeted NGS panel of 505 cancer genes. Most patients (80%) were aged 11-20 years. A history of NF1 was established in half of the cases. Mean tumor size was 8.5 cm. The most common locations included the extremities (34%) and abdomen/pelvis (27%). Histologically, 89% of high-grade MPNST showed conventional features, while the remaining three cases showed a predominant epithelioid phenotype. Heterologous differentiation occurred in 25% of high grade cases, with half showing rhabdomyoblastic differentiation. Tumors arose in a background of a plexiform neurofibroma (16%), neurofibroma (13%), and schwannoma in two cases (3%). Immunohistochemically, H3K27me3 expression was lost in 82% of conventional high-grade MPNST analyzed, while loss of SMARCB1 expression was seen in one epithelioid MPNST. Genomically, all cases showed more than one genetic abnormality, with 53% showing mutations in EED / SUZ12 genes, and 47% of cases harboring alterations in NF1 and CDKN2A/CDKN2B genes. At the last follow-up, 30% patients died of disease, 28% were alive with disease and 42% had no evidence of disease. NF1 status did not correlate with overall survival. In conclusion, half of pediatric and young adult MPNST were NF1-related and showed loss of function alterations in PRC2 complex, NF1, and CDKN2A, similar to the adult counterpart. Thus, H3K27me3 loss of expression may be used in the diagnosis of high grade MPNSTs in children. Moreover, a small subset of pediatric MPNST have an epithelioid morphology with different pathogenesis.

Pediatric peripheral nerve tumors: clinical and surgical aspects

PURPOSE

Pediatric peripheral nerve tumors (PNTs) are rare. Most are related to neurofibromatosis type 1 (NF1) with the potential for malignancy. An ongoing debate occurs about the best approach to such patients. This study describes a cohort of pediatric patients with PNTs and discusses clinical characteristics and surgical treatment.

METHODS

We retrospectively reviewed the charts of seven pediatric patients with eight PNTs surgically treated from 2007 to 2018. Information concerning patient demographics, clinical presentation, PNTs characteristics, treatment choice, and outcome were recorded.

RESULTS

All children presented with intense pain and a palpable mass. Three of the eight tumors were associated with a neurological deficit. Among the four patients with NF1, two had a neurofibroma and two a malignant peripheral nerve sheath tumor (MPNST). Histologically, three of the lesions were a benign peripheral nerve sheath tumor (BPNST), three a MPNST, and one each a desmoid tumor and Ewing's sarcoma. Two of the eight tumors underwent partial tumor excision and six gross total excisions.

CONCLUSIONS

Intense pain at rest, day, and/or night, preventing normal activities; a palpable, hard, immobile mass; an intense Tinel's sign related to the lump; clinical evidence of NF1; and high-speed growth of a tumor in the trajectory of the nerve or plexus should alert the clinician to the potential for malignancy. Preoperative biopsy is not indicated when clinical and imaging findings suggest a benign tumor. The surgical management of PNTs must be to achieve total resection, including wide margins with malignant tumors, though this is not always possible.

Treatment of neurofibromatosis 1-associated malignant peripheral nerve sheath tumors: a systematic review

Malignant peripheral nerve sheath tumors (MPNST) are a rare and aggressive group of tumors that are challenging to treat. Neurofibromatosis type 1 (NF-1)-associated MPNSTs have been associated with poorer clinical outcomes. The treatment options for NF-1-associated MPNSTs broadly include surgery (SG), chemotherapy (CT), and adjuvant radiotherapy (RT). Overall, the role and efficacy of CT and RT are unclear. Examination of existing literature for studies reporting on NF-1-associated MPNSTs and respective treatment-related outcomes was conducted. We conducted a systematic review according to PRISMA guidelines in PubMed/Medline and Cochrane databases of studies which reported treatment-specific outcomes in NF-1-associated MPNSTs. The literature search found 444 records after removal of duplicates. The present study included 50 patients across 12 observational studies. All of the included studies reported data on overall survival (OS 52%, n = 26/50) but mean follow-up in months among the studies and among patients varied widely, between 10.85 (SD, ± 10.38) and 192 (SD, ± 98.22). From the included studies, patients underwent either SG alone (n = 21), SG + CT (n = 10), SG + RT (n = 7), or SG + CT + RT (n = 12). The quality of evidence in the literature regarding optimal treatment options for NF-1-associated MPNSTs remains tenuous. Future retrospective and prospective comparative trials should consider adherence to a set of reporting guidelines to improve the quality of evidence in the literature with respect to individual treatment-related outcomes. The need for prospective multi-institutional efforts cannot be overstated.