HGMs is benign central nervous system tumor commonly diagnosed in adults, originating from the embryonic remnants of mesodermal cells. They account for 1.5–2.5% of all intracranial tumors and 7–12% of posterior fossa tumors, most occurring in the cerebellum, but also the cerebral hemispheres, spinal cord, and brainstem [3, 4]. Approximately 66%-80% of HGMs are sporadic. Hippel-Lindau syndrome, an autosomal dominant disorder, is associated with 20%-33% of HGMs and is often combined with renal or pancreatic cysts, pheochromocytoma, and retinal hemangioma [5, 6]. Previous reports were mostly single solid, cystic, or cystic-solid hemangioblastomas, this case is about multiple cystic-solid hemangioblastomas, and the site of occurrence is the same as the site of previous glioma formation, and there is no similar report in the existing papers.
At present, complete resection through surgery is still the first-line treatment of HGMs [7], since the solid part of the neoplasm is abundant with blood supply, the neoplasm should be dissected as a whole as much as possible, otherwise, it will lead to a large amount of hemorrhage during the operation, which may threaten the patient's life [3, 8, 9]. We applied midline suboccipital approach, which provided extensive exposure of the tumor and progressive separation of the tumor from the surrounding structures, with adequate hemostasis at each step to avoid intraoperative hemorrhage. The trigeminal nerve and facial-auditory nerve complex were also protected intraoperatively using neurophysiological techniques, and the patient showed no postoperative cranial nerve damage. Techniques such as extensive exposure of the operative area and circumferential dissection all contribute tremendously to the complete resection of the tumor [3, 9]. For postoperative residual neoplasms, stereotactic radiosurgery (SRS) can be used [10]. SRS is generally not required for HGMs that are completely resected by surgery. SRS is mainly suitable for postoperative residual lesions, multiple deep lesions, and lesions in the brainstem that cannot be treated by surgery. It has been shown that preoperative embolization is beneficial in reducing intraoperative bleeding [2], nevertheless, preoperative embolization remains a controversial procedure based on its relevant risks, such as ischemia, hemorrhage, and increased intracranial pressure [11, 12].
Because vascular endothelial growth factor (VEGF) is highly expressed in HGMs, endovascular chemotherapy targeting VEGF has become a novel and promising therapeutic modality. It has been reported that the anti-angiogenic drug bevacizumab and the VEGF-2 inhibitor, anlotinib, both showed inhibitory effects on the growth of HGMs [13, 14]. According to statistics, about 25% of HGMs will recur after surgical resection. Re-operation after recurrence is highly traumatic for patients and the difficulty of surgery is further increased due to postoperative intracranial structural changes. Therefore, chemotherapy has great potential for the treatment of HGMs in terms of reducing trauma.
In conclusion, although central nervous system hemangioblastoma is a benign tumor, its solid part is characterized by a rich blood supply, and its formation location is mostly located in the brainstem, cerebellar earth, and spinal cord [15], which makes surgery extremely difficult and risky and is a great challenge for neurosurgery.