Case reportInconclusiveLimited evidenceTier 3 · early humann = 1
Journal of neurosurgery. Case lessons · Mar 2026 · illustrative case report
primary intracranial sarcoma
This is a single-patient case report of a 55-year-old man who presented repeatedly over about 5 months with recurrent right frontal intraparenchymal hemorrhage. Multiple imaging studies including MR spectroscopy initially failed to identify an underlying lesion; only on the most recent presentation did MRI show a hemorrhagic mass that was resected and diagnosed as a primary intracranial sarcoma (DICER-1-mutant). The authors emphasize caution interpreting negative MR spectroscopy in hemorrhagic neoplasms and note difficulty timing resection when the cause of spontaneous IPH is unclear.
Key findings
- A 55-year-old man had recurrent, symptomatic right frontal intraparenchymal hemorrhage over an approximately 5-month period.
- Multiple imaging modalities, including MR spectroscopy, initially failed to identify an underlying lesion.
- On the most recent presentation MRI demonstrated evidence of a hemorrhagic mass.
- The hemorrhagic mass was resected and found to be a primary intracranial sarcoma (DICER-1-mutant).
- The report highlights the need to interpret negative MR spectroscopy results with caution in hemorrhagic neoplasms and the difficulty of determining optimal resection timing when spontaneous IPH has no clear etiology.
Limitations: Single-patient case report (n=1); findings may not generalize.; Observational retrospective description without control or comparison.; No quantitative diagnostic performance data provided for MR spectroscopy or other modalities.; Limited follow-up and limited detail about molecular/therapeutic implications in the abstract..
AI summary of the abstract, human-reviewed · Sep 2026. Describes what this study reported, not medical advice. View on PubMed · Full text
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