Endocrine Abstracts

Introduction: Germinomas, which are the most common germ cell tumors of the central nervous system, may present with different symptoms depending on the location and are localized in the 20-30% suprasellar region. Here, we aimed to present a case of suprasellar germinoma with central diabetes insipidus, hypogonadism and secondary adrenal insufficiency.

Case Report: A 27-year-old male patient presented with dry mouth, polydipsia, polyuria and nocturia for 6 months. There were weakness, blurred vision and erectile dysfunction. Neurological and other system examinations were normal. He did not have a chronic disease and did not take any medication. There was a history of smoking. Laboratory examinations (Table-1) revealed central hypogonadism, low cortisol level and elevated prolactin. Hydrocortisone replacement was started due to secondary adrenal insufficiency in the patient who did not respond to the insulin tolerance test and glucagon stimulation test performed for secondary adrenal insufficiency due to low cortisol level. Fluid restriction test was performed due to low urine density; it was compatible with central diabetes insipidus and the patient was started on desmopressin. Pituitary magnetic resonance imaging (MRI) revealed a 12.2x12.7 mm suprasellar mass behind the pituitary stalk. There was no contact with the optic chiasm. On eye examination, the visual field and optic disc were normal. HCG level, a tumor marker, was high. The patient was consulted with medical oncology and neurosurgery; because the suprasellar lesion was in a risky location for resection, histological examination could not be performed and it was concluded that it was a germinoma as a result of radiological and biochemical evaluations. Since it is known that intracranial germinomas have high radiosensitivity, radiotherapy was planned for the patient in the first stage. In the follow-ups, it was observed that the disease activity decreased and the adrenal insufficiency and diabetes insipidus clinic regressed.

Conclusion: Germinomas are highly treatable lesions when diagnosed early. Since visual symptoms, endocrinopathies such as diabetes insipidus and hypopituitarism may be present in suprasellar lesions, they should be managed by a multidisciplinary team consisting of neurosurgeon, endocrinologist, ophthalmologist, radiation and medical oncologist.