Multiple Cyst-like Lesions of Cerebral Sulci in Brain Metastases.

A 76-year-old man presented to our hospital with diplopia and ptosis on the right side due to oculomotor nerve palsy. Brain magnetic resonance imaging revealed multiple cyst-like lesions with contrast enhancement in the left cortical sulci, resembling neurocysticercosis (Figure 1). In addition, noncystic meningeal thickening with contrast enhancement was observed in the left hemisphere. CSF examination showed no pleocytosis, cultured bacteria, or antibodies against Toxoplasma or other parasites. Abdominal CT revealed intrahepatic bile duct dilatation and a hilar mass. Biliary cytology revealed cholangiocarcinoma. Pathologic examination of the brain biopsy specimen showed a well-differentiated adenocarcinoma with mucus in the parenchyma and arachnoid (Figure 2). The brain lesions were diagnosed as metastases from cholangiocarcinoma. The patient refused receiving any treatment for the carcinoma and died about 1 year after the biopsy. In this patient, the mucus secreted by the carcinoma and meningeal adhesions probably caused the rare cyst-like lesions in the sulci.