Endoscopic-Assisted Anterior Petrosectomy for a Recurrent Petrous Chondrosarcoma in Ollier Disease: 2-Dimensional Operative Video.

Ollier disease (OD) is characterized by the formation of multiple enchondromas. Patients with OD can develop malignant tumors, most often chondrosarcomas. When chondrosarcomas occur at the skull base in OD, cure is often difficult to obtain by surgery being lesion limits poorly distinguishable within the extensive pathological bone. Owing to the possible multiplicity of lesions over time, radiotherapy, in particular proton therapy, should be used with caution. The goal of surgery is therefore maximal resection with functional preservation followed with a careful follow-up. In this video, the case of a 13-year-old girl with an OD and an incidentally found petrous apex chondrosarcoma is presented. An endoscopic endonasal biopsy was performed confirming the diagnosis of chondrosarcoma. Conservative management was chosen initially. Because of symptoms progression and significant tumor growth, surgical removal was proposed. Considering the limited pneumatization of the sphenoid sinus and the lateral location of the lesion, an endoscopic-assisted anterior petrosal approach was chosen. A small remnant of tumor was left below the internal auditory canal. Because of its progressive growth, an additional resection using the same surgical approach was performed, with additional anterior petrosal drilling along and below the cochlea under endoscopic guidance to remove the part of the lesion located under the internal auditory canal. Ultimately, gross total resection of the lesion was achieved. All human studies have been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. The patient's relatives provided informed consent to the surgical treatment, video recording, and publication of the data. The patient's relatives provided consent to the procedures. This work was performed according to the ethical standards of our Institutional Review Board, without the need for dedicated IRB approval.