Clival intraosseous myxoma treated with an endoscopic endonasal approach: illustrative case

BACKGROUND: Solitary lesions of the clivus, especially nonchordomatous ones, are exceptionally rare pathologies representing only 0.1%–0.2% of intracranial tumors that may present diagnostic and therapeutic challenges. Intraosseous myxomas are benign tumors arising from mesenchymal cells with an unknown pathophysiology. OBSERVATIONS: In this article, a 15-year-old male with clival intraosseous myxoma who was treated via an endoscopic endonasal surgical approach is presented. The patient became symptomatic after a baseball struck his head, leading to throbbing headaches and visual difficulties for tracking objects. Examination noted diplopia, cranial nerve VI palsy, and ptosis. After imaging revealed a tumor extending to the left cavernous sinus with bulging of the dorsal clivus against the basilar artery/ventral pons, resection was performed. Postoperatively, the patient noted ocular motility and alignment improvement without further complications. LESSONS: Clival masses present with symptoms from compromised neurovascular structures including visual disturbances and trigeminal sensory deficits. Given the rarity of these entities, patients may postpone further treatment until workup; this patient was misdiagnosed for possible concussion until several weeks passed. A PubMed database review of cranial myxoma cases was conducted to identify solitary clival intraosseous myxoma cases. This case is one of the few in which this pathology was treated through an endoscopic endonasal operative approach without complications, demonstrating its safety and effectiveness.