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 17-year-old boy complained of a 2-month history of visual field defects. Two months prior to this, he experienced sudden deterioration of visual acuity on his left eye and visual field defects on the right. His symptoms remained unchanged for the next 2 months. Upon admission, his visual acuity was 0.05 in the left eye and 0.7 in the right eye. Goldmann perimetry field test showed right homonymous hemianopsia without left eye foveal sparing. Brain MR imaging showed a poorly enhanced lesion 1.9 × 1.7 × 2.1 cm in size in the posteroinferior aspect of the optic chiasm (). The mass extended to the perimesencephalic cistern with multiple stages of hemorrhage. A differential diagnosis included CM, craniopharyngioma and germ cell tumor. To decompress the mass effect around the optic chiasm and improve the patient's visual symptoms, surgical decompression via subfrontal interhemispheric approach was performed. A brownish discoloration was noted around the left side of optic chiasm and tract. A dark chocolate-colored hematoma gushed out, and a mulberry-like lesion was removed. The pathological diagnosis was consistent with the CM. The postoperative MR imaging showed partial resection of CM (). At the patient's 1-year follow-up, his visual acuity improved (1.0/0.4), although visual field defect remained unchanged. However, 2 years after the first operation, the patient complained of worsening visual acuity (0.3/finger count 10 cm). Visual field examination showed impairments in which the left eye only detected the right lower quadrant in the visual field and the right eye had nasal hemianopsia. MR imaging revealed recurrent bleeding (). The patient underwent a second operation resulting in a partial resection. Immediately following the second operation, his visual acuity (0.4/finger count 10 cm) and field improved slightly.