Pineal region pilocytic astrocytoma showing uncommon growth: a case report

Pineal region pilocytic astrocytomas are extremely rare, and there is limited information about their radiological features. We report the case of a 22-year-old woman with a cystic lesion in the pineal region. In the 2 years after diagnosis, the lesion irregularly extended along the bilateral internal cerebral veins and the inferolateral surface of the corpus callosum. Gross total resection was achieved, and the histopathological study revealed that the lesion was a pilocytic astrocytoma. The lesion exhibited uncommon growth, leading to difficulty in establishing an accurate preoperative diagnosis. It should be noted that pineal region pilocytic astrocytomas can demonstrate atypical appearances.