Endoscopic endonasal extreme far-medial approach for a lower clivus osteochondroma in a patient with hereditary multiple exostoses: illustrative case

Abstract

BACKGROUND The authors reported on the use of endoscopic endonasal surgery (EES) for clivus osteochondroma in a patient with hereditary multiple exostoses (HME), a rare pediatric disorder characterized by the formation of osteochondromas adjacent to the growth plates of the axial and appendicular skeletal elements. OBSERVATIONS A 26-year-old man with a family history of HME reported progressive hoarseness and dysphagia over the previous 6 months. He was referred to us after magnetic resonance imaging (MRI) showed a bone tumor in the lower clivus. MRI revealed tumor proliferation in the lower clivus and its extension to the bilateral occipital condyle and jugular tubercle. The hypoglossal canal and jugular foramen were encased on the right side, whereas the medulla oblongata was compressed. The tumor was subtotally resected with EES, and the brainstem was successfully decompressed. The pathological diagnosis was exostoses. Transient postoperative worsening of dysphagia improved within 1 month without other neurological deficits. The patient underwent posterior occipitoaxial fixation 3 months after EES to correct instability and local lateral tilt of the right atlanto-occipital joint. LESSONS The authors’ experience showed that EES is effective for resection of lower clivus osteochondromas, including the cartilaginous cap, and may improve clinical outcomes in patients with HME.

Giant skull base periosteal chondroma treated with endonasal endoscopic surgery: illustrative case

“…The distinctive characteristics setting periosteal chondroma apart from other chondromas include the absence of systemic diseases such as Ollier disease, Maffucci syndrome, and hereditary multiple exostoses, as well as the lack of malignant transformation in periosteal chondroma, a contrast to some other chondromas that may manifest these features. [20][21][22][23] Consequently, the decision was made to pursue observation instead of opting for an aggressive second surgery. However, Lewis et al 13 noted that six of 165 affected cases were affected by local recurrence, a rate of incidence of 3.6%.…”