Depression and Nystagmus as the Rare Masquerading Presentations of Pineal Germinoma

Convergence-retraction nystagmus alongside behavioral changes can be rare manifestations of a potentially life-threatening midbrain lesion. After experiencing headaches for three months, a 13-year-old boy was diagnosed with depression due to exhibiting reduced speech, hypersomnia, and psychomotor slowing for three weeks. It was preceded by headache for three months. Examination revealed visual acuity of 6/6 bilaterally, convergence-retraction nystagmus worst on upgaze, limited bilateral ocular motility in upgaze, and light-near dissociation on pupil examination, all of which point towards Parinaud's syndrome. However, there was no lid retraction to suggest Collier's sign. Fundus examination revealed papilledema. Magnetic resonance imaging showed a large pineal mass extending to both thalami, dilated ventricles due to obstructive hydrocephalus, and cerebral edema. An urgent external ventricular drain was inserted, and biopsy revealed pineal gland germinoma. Chemotherapy and radiotherapy resulted in adequate tumor shrinkage. This case report highlights that subacute behavioral changes may mask a potentially life-threatening intracranial tumor, especially when associated with abnormal eye movement.