Teaching NeuroImages: Intracranial DICER1-associated spindle cell sarcoma.

An 8-year-old boy presented with a 2-week history of worsening right-sided headache and left-sided jerking movements. Symptoms were associated with vomiting, photophobia, phonophobia, and diplopia but no loss of consciousness. cEEG demonstrated increased voltage on the right but no evidence of seizures. Brain MRI demonstrated a large right frontoparietal mass (figure 1). The pathologic findings were compatible with DICER1 -associated pleomorphic spindle cell sarcoma (figure 2). Recently described, DICER1 mutation predisposes individuals to development of a subgroup of tumors termed “spindle cell sarcoma with rhabdomyosarcoma-like features, DICER1 mutant” although it may present as “primary intracranial sarcoma, DICER1 -mutant.”1,2