Intracranial Atypical Cartilaginous Tumor (Low-grade Chondrosarcoma) Involving Temporal Bone, Clivus, Sphenoclival Synchondrosis, and Cavernous Sinus: A Rare Case Report.

Abstract: Intracranial atypical cartilaginous tumors (ACTs) or low-grade chondrosarcoma are rare among all skull base and intracranial tumors. Late diagnosis leads to higher morbidity and worsened neurological deficits caused by neurovascular compression. Intracranial ACTs have a higher mortality rate than other ACTs due to their location, difficulty of surgical management, local invasiveness, and recurrence rate. This report aims to highlight the challenges of diagnosing and managing intracranial ACTs, which can present with symptoms mimicking other cranial base tumors. It also aims to raise awareness about the possibility of misdiagnosis, which can lead to futile pharmacological treatment. To the best of the authors' knowledge, no published cases of intracranial ACTs from Indonesia have been reported. A 43-year-old female with complaints of chronic left facial numbness and paralysis, diplopia, tinnitus, and posture and exertion-related headache with worsening symptoms for the last 2 months, especially after waking up in the morning, with a disturbance of the left cranial nerves V-2, V-3, VI, VII, and VIII. The patient had been receiving symptomatic treatment repeatedly with several differential diagnoses for one-prior-year due to an underdiagnosis. Magnetic resonance imaging showed a mass with bone destruction located on the left temporal bone involving sphenoclival synchondrosis, clivus, and cavernous sinus with a ring-and-arch-forming calcification with the lytic pattern. After total gross resection, the diagnosis of ACTs was confirmed by a histopathological specimen that shows an abundant lobulated mass composed of uniform hyaline cartilage matrix, increased cellularity, and myxoid changes. Continuous follow-up is necessary because ACTs have a mild recurrence rate despite a high postsurgical survival rate.