SAT-484 Pituitary Microadenoma and Cerebral Venous Thrombosis in a Patient with Transient Adipsic Diabetes Insipidus after Treatment for Craniopharyngioma

Abstract

Background Craniopharyngioma is a rare embryonic sellar malformation, that can present with headache, motor and cranial nerve palsies. Treatment of large masses involves surgical excision followed by radiation therapy. Hypopituitarism and diabetes insipidus are some of the post-operative complications. Rarely, patients may develop inability to appreciate fluid losses, resulting in marked hypernatremia and dehydration associated with life-threatening lower extremity thrombosis and pulmonary embolism. We present a patient developing cerebral venous thrombosis resulting from transient adipsic diabetes insipidus accompanied by new-onset pituitary microadenoma. Clinical A 39-year-old female post-excision and radiation therapy for craniopharyngioma developed hypopituitarism and diabetes insipidus. Three months after initiating radiotherapy, she presented with headache and inability to sense thirst. She took desmopressin 100 mcg tablet only three times for the past month. There was hypernatremia at 154 meq/L (Normal Value 135-145 meq/L) and hyperprolactinemia at 235 ng/mL (NV 5.11-26.19 ng/ml). Contrast-enhanced MRI revealed cerebral venous thrombosis and a pituitary microadenoma. Thrombosis has been attributed to plasma volume contraction and consequent plasma hyperviscosity. She was started on enoxaparin, hydration with hypotonic solution, desmopressin 100 mcg tablet and bromocriptine 2.5 mg tablet for the possibility of new-onset prolactin secreting pituitary microadenoma. There was decrease in headache severity and normalization of sodium level. She was discharged on apixaban 2.5 mg tablet twice a day, bromocriptine, levothyroxine 100 mcg tab daily, desmopressin daily or at least twice a week and hydrocortisone 20 mg tab daily. After three months, she had increased ability to sense thirst but still had occasional headaches. Imaging showed partial resolution of thrombosis. Prolactin decreased to 0.925 ng/mL (NV 3-20 ng/ml). In general, prolactinomas have serum prolactin that parallel tumor size. Rarely, minimal prolactin elevations may be consistent with a prolactinoma, but a non-prolactin secreting mass should first be considered in the presence of a microadenoma. The initially elevated prolactin has been attributed to disruption of dopamine inhibition to the pituitary lactotrophs. Serial imaging of the pituitary microadenoma appears to be a reasonable follow-up. Prompt evaluation must be done should there be any signs and symptoms of hormonal hypersecretion or if there is increase in size of the microadenoma. Conclusion This is the first case to demonstrate cerebral venous thrombosis and new-onset pituitary microadenoma in a patient developing transient adipsic diabetes insipidus after treatment for craniopharyngioma. These entities must be included in the workup of patients presenting with headache. No relevant disclosures.