Treatment of Clival Giant Cell Tumor: A Case Report and Literature Review.

Giant cell tumors (GCTs) are locally aggressive primary bone tumors of osteoclast-like cells. Most GCTs occur within the long bones, and primary GCTs involving the clivus are extremely rare. We present the case of an 18-year-old boy with binocular horizontal diplopia with an insidious onset who was found to have a hypointense enhancing mass involving the clivus and left side dorsum sellae on magnetic resonance images. The tumor was completely resected via an endoscopic endonasal transclival approach, and histopathologic examination via immunohistochemistry indicated a GCT. The patient's left abducens nerve palsy improved slightly after surgery. Because of the rarity of GCTs, there is no consensus about the definitive treatment protocol. However, we suggest that gross total resection is the treatment of choice, and denosumab plays a critical role in patients with subtotal resection.

Factors Limiting Complete Resection in the Subarachnoid Space in Endoscopic Surgery for Giant Pituitary Adenoma.

OBJECTIVES: Giant pituitary adenomas (>4 cm, GPAs) have presented great challenges to surgeons because the residual tumor in the subarachnoid space can cause hemorrhage or vessel injury following apoplexy. This study aimed to investigate the factors limiting surgical success in endoscopic skull base surgery (ESS) for GPAs. METHODS: ESS was performed on 67 consecutive patients with GPAs from 2010 to 2020. We retrospectively analyzed the clinical and radiologic features and surgical outcomes. Correlations between the tumor characteristics and extent of resection were statistically presented with odds ratios (ORs). RESULTS: Preoperative visual and hormonal impairments were present in 59 (88.1%) and 55 patients (82.1%), respectively. Gross total resection (GTR) was achieved in 58.2% of patients, and the tumor remained on the lateral side of the subarachnoid space or the cavernous sinus when complete resection failed. The tumor volume, maximal diameter, multilobulated shape, cavernous sinus invasion, posterior fossa extension, and extent of suprasellar lateral extension of tumors were significantly correlated with incomplete resection. In tumors with subarachnoid lateral extension, greater distances from the medial wall of the proximal cavernous internal carotid artery to the most lateral tumor significantly increased the risk of incomplete resection for the suprasellar lateral portion of the tumor, with an OR of 1.21. CONCLUSIONS: Considerable surgical planning in ESS for GPAs is crucial for complete resection and patient safety. We elucidated that lateral extension of tumors in the subarachnoid space hindered the surgical success of the suprasellar portion of the tumor.