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 ().
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.