Isolated oculomotor nerve palsy caused by a mucocele of an aerated anterior clinoid process

Anterior Clinoid Metastasis Removed Extradurally: First Case Report

Background  We report a case of isolated metastasis on the anterior clinoid process (ACP) mimicking meningioma.

Clinical Presentation  A 58-year-old male presented with headaches, right-sided visual disturbances, and blurred and double vision. The cause of double vision was partial weakness of the right III nerve, resulting from compression of the nerve by “hypertrophied” tumor-involved right anterior clinoid. Medical history revealed two primary malignant tumors—male breast cancer and prostate cancer (diagnosed 6 and 18 months prior, respectively). The patient was treated with chemotherapy and showed no signs of active disease, recurrence, or metastasis. Postcontrast head magnetic resonance imaging (MRI) showed extra-axial well-bordered enhancing mass measuring 1.6 × 1.1 × 1 × 1 cm (anteroposterior, transverse, and craniocaudal dimensions) on the ACP, resembling a clinoidal meningioma. Extradural clinoidectomy with tumor resection was performed via right orbitozygomatic pretemporal skull base approach. Visual symptoms improved. Follow-up MRI showed no signs of tumor residual or recurrence.

Conclusion  This is the first case report of a metastasis of any kind on ACP. Metastasis should be included as a part of the differential diagnosis of lesions of the anterior clinoid. Extradural clinoidectomy is a safe and effective method in the treatment of these tumors.

Recurrent Optic Neuropathy Caused by a Mucocele of the Anterior Clinoid Process after a 5-Year Remission: A Case Report and Literature Review

A 32-year-old male presented with acute left vision loss during a second recurrence of optic neuropathy. Steroid pulse therapy had been effective in both the first episode 9 years previously and the first recurrence 5 years previously. Magnetic resonance imaging demonstrated an anterior clinoid process mucocele compressing the optic nerve. Although surgical treatment was performed, improvement was limited. This report indicates that steroid pulse therapy could be an alternative treatment to obtain temporary remission, but surgical treatment should be considered to prevent irreversible neurological deficits. This paper also presents a review of the literature on anterior clinoid process mucoceles.