ReviewMechanismInconclusiveLimited evidenceTier 4 · clinical
AJNR. American journal of neuroradiology · May 2025 · narrative review
mesenchymal nonmeningothelial tumors of the central nervous systemFET::CREB fusion-positive tumorsCIC-rearranged sarcomaprimary intracranial sarcoma, DICER1-mutantdural angioleiomyomaspindle cell neoplasm with NTRK rearrangement
This narrative review summarizes the WHO CNS5 updates to the classification and diagnostic criteria for mesenchymal nonmeningothelial CNS tumors and aligns CNS entities with soft-tissue tumor taxonomy. It highlights newly defined histomolecular entities (FET::CREB fusion-positive, CIC-rearranged sarcoma, and DICER1-mutant primary intracranial sarcoma), discusses emerging entities such as dural angioleiomyomas and NTRK-rearranged spindle cell tumors, and emphasizes that molecular techniques are essential for accurate diagnosis because histology and immunophenotype are often nonspecific.
Key findings
- WHO CNS5 substantially revised terminology and diagnostic criteria for mesenchymal nonmeningothelial CNS tumors to better align with soft-tissue tumor classification.
- The CNS chapter includes entities that occur exclusively or primarily in the CNS, most arising from the meninges and mainly located in the supratentorial compartment.
- These tumors are grouped into soft tissue, chondro-osseous, and notochordal categories; soft tissue tumors are subdivided into fibroblastic, vascular, and skeletal muscle subtypes.
- A new subcategory 'tumors of uncertain differentiation' includes three histomolecular entities: FET::CREB fusion-positive, CIC-rearranged sarcoma, and primary intracranial sarcoma, DICER1-mutant.
- Emerging entities such as dural angioleiomyomas and spindle cell neoplasms with NTRK rearrangements are discussed though not included in WHO CNS5.
- Because histology and immunophenotype are often nonspecific for tumors of uncertain differentiation, molecular techniques have become indispensable for accurate diagnosis.
Limitations: Narrative review without original, patient-level data reported in this article.; Not a primary research study; no new experimental results or pooled quantitative synthesis provided.; Scope and methods of literature selection are not detailed in the abstract (potential for incomplete coverage)..
AI summary of the abstract, human-reviewed · Jun 2026. Describes what this study reported, not medical advice. View on PubMed · Full text
Human · observationalMixed resultsLimited evidenceTier 3 · early humann = 25
Surgical neurology international · Nov 2024 · retrospective case series
primary intracranial sarcoma
This retrospective case series reviewed 25 children with primary intracranial sarcoma seen at a tertiary hospital in Peru from 2020–2023. Most presented with intracranial hypertension and radiologic hemorrhage; emergency craniotomy was common and gross total resection was achieved in 72% at first surgery. An adjuvant CTX-RT-CTX regimen was given to 72% of cases; among patients followed >1 year, those who started this regimen 2 weeks after gross total resection had survival >1 year compared with those who began complementary treatment after 4 weeks. The authors report an apparent increase in pediatric PIS incidence in recent years at their center.
Reported effects: cases_identified 25, n=25 · median_age 5, n=25 · +7 more
Key findings
- Twenty-five pediatric PIS cases identified (study period Jan 2020–Dec 2023).
- Median age was 5 years; slight female predominance (56%).
- 68% presented with features of intracranial hypertension; radiologic cerebral hemorrhage was present in 80% of those with ICH and convulsion.
- All but one case had a supratentorial tumor.
- Emergency craniotomy was performed in 84% of cases; gross total resection (GTR) at first surgery achieved in 72% of cases.
- An adjuvant chemoradiotherapy-chemotherapy (CTX-RT-CTX) regimen was used in 72% of cases; 12% started this regimen 2 weeks after surgical resection.
- Cases followed >1 year that received CTX-RT-CTX after GTR had survival >1 year compared with cases that received complementary treatment after 4 weeks.
- The authors state the incidence of pediatric PIS has increased in Peru in recent years.
Limitations: Retrospective, single-center case series.; Small sample size (n=25).; No randomized or contemporaneous control group for the timing of adjuvant therapy comparison.; Survival comparison by timing of adjuvant therapy is not quantified and may be confounded by selection and follow-up bias.; Follow-up duration is not fully reported for all cases.; No statistical testing or confidence intervals reported in the abstract..
AI summary of the abstract, human-reviewed · Jun 2026. Describes what this study reported, not medical advice. View on PubMed · Full text
Case reportMechanismInconclusiveLimited evidenceTier 3 · early humann = 1
Surgical neurology international · Jul 2024 · case report
primary intracranial sarcoma
This is a single-patient case report of a 26-year-old man with a high-grade primary intracranial sarcoma found to have a DICER1-associated genomic profile. The tumor showed unusual hypervascularity with refractory hemorrhage and subdural effusions. Management included endovascular embolization, multiple surgeries, intrathecal etoposide, oral pazopanib, and adjuvant radiation; the abstract does not provide quantitative outcomes of these treatments.
Studied with: endovascular embolization, multiple surgical interventions, adjuvant radiation therapy.
Key findings
- Patient had a high-grade spindle-celled neoplasm with sarcomatous features, multinucleated giant cells, and rare eosinophilic spheroids.
- Genomic analysis identified the tumor as DICER1-associated primary intracranial sarcoma.
- The case demonstrated anomalous hypervascularity, refractory hemorrhage, and subdural effusions as part of the presentation.
- Therapies used included endovascular embolization, multiple surgical interventions, intrathecal etoposide injections, oral pazopanib, and adjuvant radiation therapy.
Limitations: Single-patient case report — findings may not generalize.; No control group or comparative data.; Abstract does not report quantitative outcomes or measures of treatment effectiveness.; Short/unclear follow-up and limited clinical outcome details in the abstract..
AI summary of the abstract, human-reviewed · Jun 2026. Describes what this study reported, not medical advice. View on PubMed · Full text