Pineal parenchymal tumors are rare. Of the three types of
pineal parenchymal tumors,
pineocytomas are the least aggressive and are not known to diffusely disseminate. In this paper, we report the successful treatment of a case of
pineocytoma with diffuse leptomeningeal relapse following initial stereotactic
radiotherapy. A 39-year-old female presented with
headaches, balance impairment,
urinary incontinence, and blunted affect. A pineal mass was discovered on magnetic resonance imaging (MRI). A diagnosis of
pineocytoma was established with an endoscopic pineal gland biopsy, and the patient received stereotactic
radiotherapy. Ten years later, she developed diffuse leptomeningeal dissemination. The patient was then successfully treated with craniospinal
radiation therapy. Leptomeningeal spread may develop as late as 10 years after initial presentation of
pineocytoma. Our case demonstrates the importance of long-term follow-up of patients with
pineal parenchymal tumors following
radiation therapy, and the efficacy of craniospinal radiation in the treatment of leptomeningeal dissemination.