CNS Metastases from Bone and Soft Tissue Sarcomas in Children, Adolescents, and Young Adults: Are They Really So Rare?

An Evaluation of Risk Factors for Intracranial Metastases of Sarcomas: A Systematic Review and Meta-Analysis

INTRODUCTION

Sarcomas, a group of neoplasms comprising both tissue and bone soft tissue tumors, has an increasing prevalence in recent years. Prognosis significantly hinges on early detection, and if not detected early, may consequently metastasize. This review will be the first systematic review and meta-analysis characterizing the presentation and progression of brain metastases from bone and soft tissue cancers.

METHODS

The PubMed, Scopus, and Web of Science databases were queried to identify studies reporting the incidence of intracranial brain metastases from primary sarcoma to the present. Abstract and full-text screening of 1822 initial articles returned by preliminary search yielded 28 studies for inclusion and data extraction. Qualitative assessment of the studies was conducted in accordance with the Newcastle-Ottawa Scale criteria. Meta-analyses were applied to assess risk factors on outcomes.

RESULTS

The average age within the cohort was 27.9 years with a male and female prevalence of 59.1% and 40.9%, respectively. The odds ratio for living status (dead/alive) was calculated for several risk factors - male/female [OR 1.14, 95% CI 0.62, 2.07], single/multiple metastases [OR 0.67, 95% CI 0.35, 1.28], lung metastases/not [OR 1.63, 95% CI 0.85, 3.13], surgery/no surgery [OR 0.49, 95% CI 0.20, 1.21]. The standardized mean differences for duration from diagnoses to metastases were likewise analyzed - male/female [SMD 0.13, 95% CI -0.15, 0.42], single/multiple metastases [SMD 0.11, 95% CI -0.20, 0.42], lung metastases/not [SMD -0.03, 95% CI -0.38, 0.32], surgery/no surgery [SMD 0.45, 95% CI -0.18, 1.09]. The standardized mean differences for duration from metastases to death were analyzed - lung metastases/not [SMD 0.43, 95% CI -0.08, 0.95].

CONCLUSIONS

Our study observed no statistically significant differences in mortality rate among several patient risk factors. Consequentially, there lacks a clear answer as to whether or not an association between mortality rates exists with these patient factors. As such, it is important to continue research in brain-metastasizing sarcomas despite their relative rarity.

Characterization of pediatric non-hematopoietic tumor metastases to the central nervous system: A single institution review

Central nervous system (CNS) metastases represent a small portion of pediatric CNS neoplasms and data surrounding this condition with high morbidity is scarce. Single institutional archival institutional pathology records between 1999 and 2022 were searched for patients over 21 years old and younger with CNS, dura, cranial nerve, CSF, or leptomeningeal metastases; 41 cases were identified. We documented primary tumor types and locations, metastasis locations, types of invasion (direct extension vs distant metastasis), times from imaging or pathologic diagnosis to CNS involvement, and outcomes. Distant metastasis was the most common mechanism of metastasis (n = 32, 78%). Interval times to CNS metastasis varied by both tumor type and primary tumor location. In this cohort, osteosarcoma portended the shortest survival following CNS metastasis. This study highlights the diverse mechanisms and locations of CNS involvement in pediatric CNS metastases and illuminates a need for varied monitoring strategies when considering primary tumor type and anatomic location.

Central Nervous System Metastases in Pediatric Patients With Ewing Sarcoma

Metastatic central nervous system (CNS) involvement is rare in pediatric primary extracranial Ewing sarcoma (ES). We describe the incidence and course of 6 patients with extracranial ES who developed metastatic CNS lesions treated at a single institution. The median time to CNS disease detection was 16.3 months (10.0-28.3 months). Event-free and overall survival after CNS disease detection were 1.9 months (0.4 to 10.3 months) and 4.6 months (1.1 to 50.9 months), respectively. One patient was alive at the time of analysis. Clinical status and ability to obtain disease control should be considered when making decisions regarding aggressive interventions in these patients with poor prognosis.

Brain metastases of sarcoma: a rare phenomenon in rare tumours

The usual site for distant metastases of sarcoma is lungs, while brain metastasis (BM) occurs much less frequently and usually late in the disease progression. Despite the advancement in cancer treatment, the outcome for patients with brain metastasis is poor, and their lifespan is short. The frequency of BM in sarcoma seems to be affected by the location and histology of the primary tumour. Sarcoma subtypes with a high propensity for brain metastasis are ASPS, leiomyosarcoma and osteosarcoma. There are no clear guidelines for the treatment of sarcoma brain metastasis. However, therapeutic options include surgery, radiotherapy and chemotherapy, and are often combined. Targeted therapies are a promising treatment option for sarcoma but require investigation in patients with BM. The following review presents the data on sarcoma brain metastasis incidence, treatment and prognosis.

Intracranial Metastasis of Extracranial Chondrosarcoma: Systematic Review With Illustrative Case

BACKGROUND

Cerebral chondrosarcoma metastases are rare and aggressive neoplasms. The rarity of presentation has precluded rigorous analysis of diagnosis, risk factors, treatment, and survival. We analyzed every reported case through exhaustive literature review. We further present the first case with Maffucci syndrome.

METHODS

Three databases, PubMed, Embase, and Google Scholar, and crossed references were queried for cerebral chondrosarcoma metastases. Extracted variables included demographics, risk factors, tumor characteristics, interventions, and outcomes. Univariate and multivariate analyses were performed.

RESULTS

Fifty-six patients were included from 1,489 literature results. The average age at brain metastasis was 46.6±17.6 years and occurred at a median of 24±2.8 months from primary diagnosis. Primary tumor histology (dedifferentiated 5.0±1.5 months, mesenchymal 24±3.0 months, conventional 41±7.4 months, p<0.05) and grade (low grade 54±16.7 months vs. high-grade 10±6.4 months, p<0.001) correlated with time interval until brain metastasis. A multiple enchondromatosis syndrome occurred in 13.2% of cases. At time of brain metastases diagnosis, extracranial metastases were identified in 76.2% of cases. Median survival after the development of brain metastasis was 2.0±0.78 months with a 1-year survival of 10.0%. On regression analysis, surgery reduced brain metastasis mortality risk and radiation trended towards reduced mortality risk (surgery: hazard ratio [HR] 0.22, 95% confidence interval [CI] 0.064-0.763, p=0.017; radiation: HR 0.31, 95% CI 0.091-1.072, p=0.064).

CONCLUSION

We present a systematic review of cerebral chondrosarcoma metastases. Primary tumor histology and grade correlate with time until cerebral metastasis. Following cerebral metastasis, these tumors have poor prognosis and modestly benefit from surgery.

Desmoplastic Small Round Cell Tumor With Ascending Intraspinal Metastasis at Recurrence: Case Report and Review of the Literature

BACKGROUND

Desmoplastic small round cell tumor (DSRCT) is a rare and aggressive malignancy commonly involving the abdomen and/or pelvic peritoneum. Despite aggressive therapy, the prognosis remains poor. Central nervous system relapse is rare in abdominal/pelvic primary DSRCT.

OBSERVATION

We report a case of a 10-year-old female with a large pelvic DSRCT and involvement of the rectosigmoid colon and liver. Following treatment with chemotherapy, and cytoreductive surgery with hyperthermic intraperitoneal chemotherapy an initial response was noted. With progressive lower limb weakness, recurrence with perineural invasion in the lumbosacral nerve root involving the conus was noted 2.5 years from diagnosis. Cerebrospinal fluid showed tumor cells with a molecular confirmation.

CONCLUSIONS

Perineural invasion and ascending paralysis secondary to primary abdominal DSRCT has not been previously reported to our knowledge. We recommend a high index of suspicion for early and accurate diagnosis of this rare presentation.

Immunotherapy Associated Neurotoxicity in Pediatric Oncology

Novel immunotherapies are increasingly being employed in pediatric oncology, both in the upfront and relapsed/refractory settings. Through various mechanisms of action, engagement and activation of the immune system can cause both generalized and disease site-specific inflammation, leading to immune-related adverse events (irAEs). One of the most worrisome irAEs is that of neurotoxicity. This can present as a large spectrum of neurological toxicities, including confusion, aphasia, neuropathies, seizures, and/or death, with variable onset and severity. Earlier identification and treatment, generally with corticosteroids, remains the mainstay of neurotoxicity management to optimize patient outcomes. The pathophysiology of neurotoxicity varies across the different therapeutic strategies and remains to be elucidated in most cases. Furthermore, little is known about long-term neurologic sequelae. This review will focus on neurotoxicity seen with the most common immunotherapies used in pediatric oncology, including CAR T cell therapy, alternative forms of adoptive cell therapy, antibody therapies, immune checkpoint inhibitors, and tumor vaccines. Herein we will discuss the incidence, pathophysiology, symptomatology, diagnosis, and management strategies currently being utilized for immunotherapy-associated neurotoxicity with a focus on pediatric specific considerations.

Temporal evolution of metastatic disease: part II-a novel proposal for subcategorization of metastatic disease from non-neural solid tumors with diverse histologies and locations

Tumor spread is a continuous process and metastases can further disseminate. Currently, metastatic disease from most primary tumors is subcategorized as M0 if absent and M1 if present. However, metastatic disease in different locations may have different prognostic implications, even if it is from the same primary tumor. The current staging systems for metastatic disease have not evolved to match our understanding of the disease's evolution or the evolving treatment paradigms. Primary tumor-specific subcategorization of metastatic disease is currently available for a few tumors, but not all of them imply further remote spread of tumor, similar to tumor (T) and N (node) subcategorizations of the TNM staging, nor are they applicable to wide spectrum of other tumors. In this era of precision medicine, tumor-type agnostic therapies based on common biomarkers rather than primary tumor sites are emerging, but a subcategorization system applicable to metastatic disease from diverse primary tumor locations and with diverse histologies is not available. In this article, we discuss the need to further classify the metastatic disease and present a subcategorization applicable to metastatic disease from non-neural solid tumors from different primary tumor sites and with different histologies, which is based on the temporal spread of metastatic disease. Our proposed subcategorization scheme for metastatic disease into M0, M1, M2 and M3, is universally applicable to a diverse spectrum of non-neural solid tumors, and increasing M subcategorization represents further remote spread of tumor.

Capicua Transcriptional Repressor-Rearranged Undifferentiated Round Cell Sarcoma Metastatic to the Brain Treated with Surgery and Stereotactic Radiosurgery

BACKGROUND

Ewing-like sarcoma with capicua transcriptional repressor (CIC) rearrangement is a unique class of undifferentiated round cell sarcomas characterized by CIC-double homeobox 4 gene fusion. Despite showing great histologic resemblance to Ewing sarcomas, they have proved to be a distinct pathological entity from the immunohistochemistry and genetic examinations and the response to treatment. We have presented a case of CIC-rearranged Ewing-like sarcoma with cerebral metastasis managed with operative resection and gamma knife radiosurgery.

CASE DESCRIPTION

A 56-year-old woman had initially presented with an ulcerating lesion of the right fifth toe. The histological and immunohistochemical analysis revealed features consistent with CIC-rearranged Ewing-like sarcoma, which was confirmed with genetic analysis. Despite aggressive local control and a multidrug chemotherapy regimen, the patient developed multifocal metastases involving the lungs, femur, and cerebrum. The cerebral lesions were managed with surgery and gamma knife radiosurgery, with mixed results.

CONCLUSION

CIC-rearranged Ewing-like sarcomas have recently been recognized as a distinct disease entity with a highly aggressive course. Treatment paradigms have yet to be defined to properly manage such an aggressive pathological process.

Rare Case of Sellar and Suprasellar Metastasis from Ewing's Sarcoma of Tibia

We hereby report a case of metastatic Ewing's sarcoma presenting with rapid-onset total ophthalmoplegia, optic atrophy, and right temporal hemianopia. Comprehensive ophthalmic and neurological evaluation with targeted radioimaging revealed a tumor mass centered over the sella, compressing optic chiasma, extending to involve the left cavernous sinus and the left orbital apex. Whole-body imaging revealed the evidence of multifocal lung and mediastinal metastasis with focal lytic defect in the left femoral head. Histopathological evaluation of transnasal punch biopsy from the nasopharyngeal extension of the tumor revealed small round-cell tumor with strong CD99 positivity, supporting the diagnosis of Ewing's sarcoma. Rapid, aggressive extensions of the metastatic tumor into vital structures despite the initiation of chemoradiation of the extensive intracranial tumor led to unexpected demise of the patient. Our case is an unusual case of Ewing's sarcoma metastasis manifesting as a sellar mass and mimicking a pituitary adenoma radiologically, with a rapid progression within 2 weeks to cause massive extension of tumor into suprasellar, infrasellar, and left parasellar area, indicative of highly malignant nature of the tumor.

MRI of osteosarcoma metastases in the brain of an old English Sheepdog

A 9-year-old, male neutered old English Sheepdog was presented for further investigation of altered mentation, impaired vision, and hemineglect syndrome of 10 days duration. An MRI study of the brain revealed multifocal, contrast-enhancing intra-axial lesions that had a stippled hypointense appearance in all sequences but lacked evidence of a strong signal void on T2* images. Histological examination of the brain postmortem confirmed the lesions were metastases arising from an osteosarcoma, which was later identified in the right humerus. To the authors' knowledge, these MRI characteristics of osteosarcoma metastases in the canine brain have not been previously reported.