A 40-year-old female with past medical history of migraine and no family history of CM, presented with unilateral scotomas with a gradual onset over 7 months and progressive visual deterioration, referred as blurred vision of the right eye (RE), with a significant worsening few days before seeking medical care.\nShe was initially admitted at Ophthalmology outpatient clinic for observation. The ophthalmologic evaluation revealed a decreased visual acuity (7/10) and a visual field defect on the RE. Her left eye (LE) was completely normal (10/10, without field defect). The computerized campimetry (CC) disclosed a supero-inferior arciform defect in the RE. LE CC was normal [].\nVisual evoked potential responses showed results compatible with a right second cranial nerve dysfunction due to compressive optic neuropathy on the RE. A noncontrast enhanced computed tomography (CT) scan was performed and revealed a spontaneous hyperdense focal nodular lesion, heterogeneous, with irregular contours and a punctate area of increased attenuation coefficient related to calcification, on the right optic-carotid cistern, adjacent to the ipsilateral ON. No surrounding edema or mass effect was documented. No evidence of subarachnoid or intraventricular hemorrhage [].\nBased on the CT scan result, the patient was referred to the outpatient clinic of the Neurosurgery Department. She completed the diagnostic neuro-imaging evaluation with a CT angiography (CTA) [], a magnetic resonance imaging (MRI), and a MR angiography (MRA) of the brain.\nThe MRI showed a focal solitary well-defined rounded lesion involving the right ON in its intracranial prechiasmatic segment, sparing the chiasm. The T1-weighted noncontrasted sequence showed a spontaneously hyperintense lesion [Figures -]. In the T2-weighted MRI, the lesion exhibited a heterogeneous signal intensity and a peripheral hypointense rim [. No large vessels adjacent to the lesion were identified.\nThe MRA demonstrated a hyperintense mass due to hemosiderin. No enlarged vessels were identified [].\nThese features were considered to be consistent with an occult vascular malformation, presenting an inner hematoma (blood and blood by-products in various states of evolution) surrounded by a peripheral hemosiderin rim, suggesting the diagnosis of a CM of the intracranial segment of the right ON.\nThe patient complaints remained unchanged for one week. After this period of time, she was electively operated on, through a right pterional craniotomy. An intradural optic canal unroofing, through a drilling technique, was performed to completely expose and microsurgically remove the CM []. The CM was found over the superior surface of the ON at the entrance of the optic canal with an anterior canalicular extension.
A 16-year-old boy presented progressive visual disturbance that started 5 months prior with headache. The headache had subsided; however, the visual symptoms persisted. His visual acuity was 0.02 in his left eye and 0.3 in his right eye. The Goldmann perimetry field test revealed a large central scotoma of his left eye field and a temporal hemianopsia of his right eye field (). Brain MR imaging showed a heterogeneous hemorrhagic mass in the optic chiasm, extending posteriorly along the bilateral optic tracts with no definitive contrast enhancement (). The presumptive diagnosis was an unusual CM involving the optic pathway. Following left pterional craniotomy and sylvian dissection, the optic chiasm, which was mottled with dark dots, was visualized. A small window was made on the lateral side of the optic chiasm. Chocolate-colored tissue mixed with old blood was partially evacuated (). The pathology report confirmed the diagnosis of CM. Following surgery, the patient's visual acuity in his left eye slightly improved (0.03/0.3). The central scotoma of his left eye field had resolved; however, he subsequently acquired a nasal hemianopsia in his left eye field. At the patient's 2-year follow-up, there were no episodes of headache, visual change, or documented bleeding on serial MR imaging ().