Primary intracranial cholesteatoma in the thalamus.

Background: Primary intracranial cholesteatomas are rare, benign lesions of keratinizing squamous epithelium, often arising from middle ear extension. However, their occurrence in the thalamus is exceptionally rare, with only one prior case reported. Case Description: A 48-year-old male presented with progressive headaches over 3 years and difficulty with upward gaze. Neurological examination revealed bilateral upward gaze palsy. Magnetic resonance imaging demonstrated an intra-axial cystic mass with a solid component in the right thalamus extending to the midbrain, causing obstructive hydrocephalus. A craniotomy with subtotal tumor resection was performed. Histopathology confirmed cholesteatoma. Postoperatively, the patient's symptoms improved, but hydrocephalus recurred, necessitating an endoscopic third ventriculostomy. Five months later, imaging showed an increase in residual mass size, but further, surgical intervention was declined due to financial constraints. The patient continued outpatient follow-up and maintained functional independence despite persistent symptoms. Conclusion: Thalamic cholesteatomas are rare and diagnostically challenging. Their deep-seated location complicates surgical resection, often necessitating subtotal removal to preserve neurological function. Close postoperative monitoring is essential due to the high recurrence risk. Further research is needed to optimize diagnostic strategies and explore alternative treatment approaches for these rare lesions.