Calcified pilocytic astrocytoma of the medulla mimicking a brainstem "stone"

Area of Science:

• Neuro-oncology
• Pediatric Neurosurgery
• Neuropathology

Background:

• Brainstem gliomas are common pediatric central nervous system tumors, accounting for 10% of cases.
• Pilocytic astrocytomas, a type of low-grade glioma, typically affect the midbrain and medulla.
• Surgical resection is often curative for accessible pilocytic astrocytomas.

Observation:

• Densely calcified pilocytic astrocytomas of the brainstem are exceptionally rare.
• A young adult presented with a large, calcified brainstem mass involving the medulla.
• The mass was subtotally resected via a posterior suboccipital surgical approach.

Findings:

• The definitive pathological diagnosis of the resected tumor was calcified pilocytic astrocytoma.
• This finding highlights an unusual presentation of a typically low-grade glial tumor.

Implications:

• This case expands the known spectrum of pilocytic astrocytoma presentations.
• It underscores the importance of considering rare variants in the differential diagnosis of brainstem tumors.
• Further research may elucidate the mechanisms behind unusual calcification in these pediatric-type tumors in adults.