Rare child primary intracranial sarcoma associated with DICER1 mutation: a case report and review of the literature.

BACKGROUND

Primary intracranial sarcoma with DICER1 mutation (PIS-DICER1) is a rare and highly aggressive tumor that typically occurs in children and adolescents. Its clinical, radiologic, and pathological features are often nonspecific, making accurate diagnosis challenging.

CASE PRESENTATION: We describe a 14-year-old boy who presented with dizziness and exertional intermittent headache. MRI revealed a hemorrhagic mass in the left frontal lobe near the falx cerebri. Complete surgical resection was achieved. Histopathology demonstrated a high-grade spindle cell sarcoma with occasional desmin positivity, weak SMA staining, and negative myogenin. Genetic sequencing identified both nonsense and missense mutations in DICER1, together with missense mutations in TP53 and PDGFRB, supporting the diagnosis of PIS-DICER1. The patient subsequently received six cycles of alternating EC and VIP chemotherapy, followed by hyperfractionated radiotherapy to a total dose of 60 Gy. At 32 months of follow-up, he remained free of recurrence or metastasis.

CONCLUSIONS

PIS-DICER1 is an extremely uncommon intracranial sarcoma in which genetic testing plays a key role in establishing the diagnosis. Multimodal treatment combining total resection, intensive chemotherapy, and high-dose radiotherapy may contribute to favorable long-term outcomes. Primary intracranial sarcoma with DICER1 mutation (PIS-DICER1) is an extremely rare pediatric brain tumor lacking distinctive clinical or imaging features, making diagnosis difficult without molecular testing. We report a 14-year-old boy who presented with intracranial hemorrhage and achieved long-term disease control through repeated surgeries, intensive chemotherapy, and high-dose radiotherapy. Alongside this case, we performed an updated literature review, which demonstrates the limited evidence base and absence of standardized management strategies. Our findings highlight the essential role of comprehensive genomic analysis and suggest that timely multimodal therapy may improve outcomes in this rare and understudied tumor.