Background: We report a case in which magnetic resonance imaging (MRI) documented the formation of a neurohypophyseal germinoma from its earliest stage.
Case description: A 9-year-old girl presented with polyuria, polydipsia, and growth retardation. Urinary and endocrinological examination indicated diabetes insipidus (DI) and growth hormone deficiency. No clear evidence of a mass in the hypothalamo-pituitary area was apparent on the first MRI scan. Follow-up MRIs and endocrinological examinations revealed that a tumor, arising from the stalk and posterior lobe of the pituitary gland, formed a mass and caused anterior pituitary function to deteriorate. Histologic diagnosis was germinoma based on open biopsy.
Conclusion: Radiologic findings in this case indicated the primary site of this intrasellar germinoma to be the hypothalamo-neurohypophyseal region, designating this a "neurohypophyseal germinoma."