Abstract
Anterior clinoid process metastases are rare. We present an unusual case of anterior
clinoid process metastasis with sudden deterioration of visual function requiring
emergency optic nerve decompression, resulting in recovery of visual function. The
patient was a 41-year-old man with a diagnosis of leiomyosarcoma of the radius, operated
on in 2014, with bone and lung metastases, who had been treated with chemotherapy
and appeared to have stable disease at his last follow-up. Six years later, he developed
a 1-month history of progressive unilateral loss of visual acuity and visual field
defect (initially quadrantanopia that progressed to nasal hemianopia). Brain imaging
showed a contrast-enhancing lesion affecting the left anterior clinoid process with
extension to the cavernous sinus and sphenoid sinus, causing compression of the left
optic nerve. Although the lesion could have suggested a meningioma given the location,
in the context of the patient's oncological history, the diagnosis of metastasis was
considered more likely. The patient was admitted to the hospital and, during the hospital
stay, developed sudden left retro-orbital pain progressing to left amaurosis over
approximately 8 hours. Urgent surgery was performed: a pterional craniotomy with partial
tumor removal and optic nerve decompression with extradural anterior clinoidectomy.
After surgery, the patient had an immediate but partial improvement in visual acuity
and in the visual field defect. Metastasis to the anterior clinoid process is very
uncommon, with only one case previously reported in the literature. In cases of visual
impairment, symptoms may deteriorate rapidly to complete loss of vision, so urgent
decompressive surgery of the optic pathway may be indicated to recover visual function,
although recovery may be partial.
Keywords
anterior clinoid process - skull base metastasis - anterior clinoidectomy - visual
loss - optic nerve
