April - June 2014, Volume 10, Issue 2

Capraru OM, Pascanu I, Marginean OC

Suprasellar Germinoma with Chronic Hypernatremia, Adipsic Diabetes Insipidus and Hypopityuitarism. Case Report

Acta Endo (Buc) 2014, 10 (2): 273-282
doi: 10.4183/aeb.2014.273

Intracranial germ cell tumors (GCT) are rare brain tumors that typically arise in the pineal or suprasellar regions. Germinomas are highly radiosensitive among pediatric CNS tumors. Suprasellar GCTs most commonly present with hypothalamic/ pituitary dysfunctions. We report a case of an 18 year old boy with particularly long term evolution from the onset of symptoms to the positive diagnosis of suprasellar germinoma. At 9 years he was diagnosed with idiopathic central diabetes insipidus and started DDAVP therapy. In the subsequent years he presented delay in longitudinal growth and delayed pubertal development. At 16 years he was referred to our institute with relatively good general condition despite an extremely severe hypernatremia of 186 mEq/L, serum osmolality of 405 mOsm/kg and impaired thirst sensation. He developed sinus thrombosis as a consequence of hyperosmolality and presented intermittent rises of temperature, but no septic episodes. During a long term follow neuroimaging eventually revealed a thickening of the pituitary stalk, mimicking as an infiltrative lesion. Finally, two supracentimetric tumor nodules were shown on contrast enhanced MRI in the suprasellar region and at the floor of the left lateral ventricle. Stereotactic biopsy concluded a pure germinoma, and craniospinal irradiation was performed. At present he has an infracentimetric suprasellar tumor remnant, reperfused sinus veins, optochiasmatic syndrome sequelae. He benefits from L-Thyroxin and testosterone replacement, and maintains hydro-electrolytic balance on DDAVP and controlled oral fluid intake.

Keywords: diabetes insipidus, germinoma, hypernatremia.

Correspondence: Ionela Pascanu, MD, PhD, Associate Professor, University of Medicine and Pharmacy, Endocrinology Department, 38 Gh. Marinescu street, Tirgu Mures, 540139, Romania. E-mail: iopascanu@gmail.com