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Papillary glioneuronal tumor (PGNT) is a rare, mixed glioneuronal neoplasm characterized histologically by pseudopapillary architecture, and clinically by slow growth and seizure presentation.

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It is a WHO CNS 2021 Grade 1 tumor, with indolent behavior and excellent prognosis following surgical resection.

Epidemiology

Age: Typically presents in children and young adults (median age ~23 years)
Sex: Slight male predominance
Rarity: Comprises <0.1% of CNS tumors

Etiopathogenesis

Originates from cortical or subcortical tissue, likely from biphenotypic glioneuronal progenitors
No evidence of aggressive transformation in most cases

Molecular hallmark:

Most PGNTs harbor a SLC44A1::PRKCA fusion (specific and diagnostic)
Typically IDH-wildtype, BRAF-negative

Clinical Features

Feature	Notes
Seizures	Most common symptom due to cortical location
Headache or signs of raised ICP	Occasionally if large or periventricular
Neurologically intact	Most patients are otherwise normal
Site	Often temporal or frontal lobe; occasionally periventricular

Radiology

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Key radiological pattern: Well-circumscribed cystic lesion with enhancing solid nodule, similar to pilocytic astrocytoma or ganglioglioma

Location: Often cortically based in temporal/frontal lobes; sometimes intraventricular </aside>