SAT-237 Isolated Hypogonadotropic Hypogonadism in a Male with Sarcoidosis

Sarcoidosis is a systemic disease of unknown cause that is characterised by the formation of immune granulomas in various organs, mainly the lungs and the lymphatic system. The clinical involvement of the nervous system occurs in 5 to 15% of the cases. Any part of the nervous system can be affected, with the cranial nerves, the hypothalamus and the pituitary gland being the ones most commonly involved. However, hypothalamic-pituitary (HP) manifestations are rare manifestations of sarcoidosis, occurring in <1% of all intrasellar lesions. A 33-year old man was admitted to the emergency room with confusion and cognitive impairment progressively evolving over the past 2 months. The main complains were bilateral headaches, fatigue, adynamia and libido reduction. No visual fields defects were detected. Three months earlier, he had been diagnosed with sarcoidosis with pulmonary and ganglionar involvement, which was confirmed after histopathology analysis of tissue biopsy of the lung and mediastinic lymph nodes. However, the patient remained without any medication. He was admitted to the in-patient department and a brain MRI was performed, which revealed intense infra and supratentorial leptomeningeal enhancement, with involvement of the hypothalamus and optic chiasm. Laboratory evaluation revealed significantly reduced gonadotrophin and testosterone levels (FSH 1.1U/L, LH 0.43U/L, total testosterone 4.5ng/dL), normal prolactin and no other HP hormonal deficits. Clinical diagnosis was consistent with neurosarcoidosis with hypothalamic infiltration resulting in clinical hypogonadotropic hypogonadism. The patient initiated systemic therapy with corticosteroid, showing an overall improvement. After the hospital discharge, he started hormonal reposition with testosterone therapy with additional clinical improvement. Pituitary insufficiency is the presenting form of neurosarcoidosis in only 3 to 9% of the cases. Aside from diabetes insipidus and hyperprolactinemia, hypogonadism represents one of the endocrine disorders more frequently associated with HP involvement. Furthermore, hypothalamic sarcoidosis involvement is usually associated with multiple hypothalamic-pituitary deficits, rather than isolated ones. The case reported herein, illustrates a presumptive case of neurosarcoidosis, conducting to an isolated hypothalamic-pituitary axis deficiency. Although rare, HP involvement in neurosarcoidosis is usually associated with permanent endocrine defects. Hence, hypothalamic-pituitary axis evaluation should be performed promptly and long-term management is required.