Endoscopic Keyhole Approach Is Useful in the Diagnosis and Removal of Cystic Cerebellar Hemangioblastoma: A Case Report.

Intracranial cystic lesions such as hemangioblastoma (HB) are commonly found incidentally; however, they can be difficult to diagnose because they require various differential diagnoses. A contrast-enhanced mural nodule on magnetic resonance imaging (MRI) is typical and can be diagnosed preoperatively; however, some small nodules cannot be visualised and only cysts may be seen, complicating preoperative diagnosis. In such cases, thorough observation of the cysts is necessary for a definitive diagnosis. To achieve this, minimally invasive surgery, such as endoscopic keyhole surgery, is required. Herein, we report the case of a man in his 50s who presented with an unstable gait, and experienced dizziness for several months. Preoperative MRI revealed a cystic lesion in the left cerebellar hemisphere, without a mural nodule. Although there was no diagnostic evidence of HB, we suspected that the symptoms were caused by this cystic lesion because of its recent occurrence. Upon detecting a mural nodule, we diagnosed it as a cerebellar HB and completely resected it using an endoscopic keyhole approach. The patient's symptoms alleviated postoperatively. The endoscopic keyhole approach may be useful as a less invasive procedure for diagnosing and removing cystic cerebellar HBs, especially for lesions that are difficult to diagnose using preoperative imaging.