A 16-year-old boy presents with headache, vomiting, and inability to look upwards. Examination shows convergence-retraction nystagmus, pupils that accommodate but do not react to light, and papilloedema. MRI shows a homogeneously enhancing pineal region mass compressing the tectum with hydrocephalus. Serum beta-hCG is mildly elevated. What is the most likely diagnosis?

• A Pineocytoma
• B Choroid plexus papilloma
• C Tectal plate glioma
• D Intracranial germinoma ✓

Explanation

Parinaud syndrome, comprising upgaze palsy, convergence-retraction nystagmus, and light-near dissociation, localises to the pineal region compressing the dorsal midbrain. An enhancing pineal mass with elevated beta-hCG in an adolescent indicates germinoma, often with syncytiotrophoblastic cells. Germinomas are exquisitely radiosensitive and carry excellent survival even with CSF dissemination. Pineocytoma does not secrete beta-hCG. Tectal glioma is indolent and non-enhancing, presenting only with hydrocephalus. Choroid plexus papilloma occurs in the lateral ventricle of infants.

Reference: Greenberg's Handbook of Neurosurgery, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.