An epileptogenic intracranial cystic lesion lined with fallopian tube-type epithelium: illustrative case

BACKGROUND: Intracranial cystic lesions are often a trigger for epileptic seizures. However, there has never been a report of a cystic lesion lined with fallopian tube-type epithelium. OBSERVATIONS: A 48-year-old female presented with a cystic lesion in the right occipital lobe, which gradually grew over 8 years. Right occipital lobe epilepsy was diagnosed based on visual aura, convulsive seizures, and electroencephalogram findings and the cyst was surgically removed. Further examination revealed the cyst was lined with ciliated cells, which had morphological and immunohistochemical features similar to those of fallopian tube epithelium. LESSONS: The characteristics of the cyst did not conform to any known types of benign cystic lesion. To the authors’ knowledge, no such cyst has been reported before. The authors discuss the origins and pathogenesis of this unfamiliar cystic lesion.