SAT-488 Pituicytoma: A Rare Tumor of the Pituitary with Unique Clinically Relevant Features

Background: A pituicytoma is a rare tumor of the posterior pituitary originating from the pituicyte. Pituicytomas are often suspected to be more common tumors, like pituitary adenomas. However, unlike those tumors, pituicytomas have unique features (e.g., high vascularity and bleeding risk) that can affect their management. The infrequent diagnosis of pituicytomas makes their recurrence rate and need for ongoing monitoring undetermined. More reporting of pituicytoma cases is needed. Clinical Case: A 57-year-old male was transferred to our rehabilitation hospital after becoming debilitated from sequelae of a pituicytoma. In 1996, he was found to have a mass in the sella turcica that was diagnosed as a pituitary adenoma. He underwent radiation therapy and a craniotomy. He subsequently developed panhypopituitarism and was put on hormone replacement therapy (desmopressin, hydrocortisone, levothyroxine, and testosterone) that he took for years without any notable issue. In 2016, he developed visual field deficits. His evaluation revealed a pituitary mass. He underwent a second craniotomy and a surgical resection of the mass, which was determined to be a pituicytoma. In 2018, the pituicytoma recurred. A transsphenoidal surgical resection of the pituicytoma was attempted. However, the procedure ended early due to significant bleeding, which was important to this patient because he was a Jehovah’s Witness who declined blood products. Postoperatively, he suffered from a persistent headache that led to a second surgical resection of the residual pituicytoma via an endoscopic endonasal approach. During recovery, the patient developed significant complications including hydrocephalus, ventriculitis, and seizures, which merited inpatient rehabilitation and continuation of his hormone replacement therapy. Conclusion: Pituicytomas are infrequently diagnosed tumors of the posterior pituitary that can be difficult to initially differentiate from other pituitary masses. To develop better diagnostics, treatment, management, and surveillance guidelines, reporting of pituicytomas is needed. This case shows the importance of accurate diagnosis and provides data on the likelihood/timing of potential recurrences and complications that might arise during treatment.