Neurosarcoidosis-Induced Panhypopituitarism

Abstract

Sarcoidosis is an inflammatory condition that can impact multiple organs in the body such as the lungs, skin, eyes, and, occasionally, the central nervous system. When sarcoidosis affects the nervous system, it is referred to as neurosarcoidosis and is estimated to occur in approximately 5%-15% of sarcoid patients. When neurosarcoidosis affects the pituitary gland, it can result in panhypopituitarism, which can be life-threatening. A 35-year-old male with a known diagnosis of sarcoidosis by skin biopsies presented to the hospital with altered mental status, hypernatremia, hypotension, and hypothermia. He reported symptoms of polyuria and polydipsia for several weeks before admission. Laboratory workup revealed elevated serum sodium at 167 mmol/L, high serum osmolality at 381 mOsm/kg, and low urine osmolality at 381 mOsm/kg, consistent with diabetes insipidus. Anterior pituitary hormone profile workup revealed low 8 am serum cortisol (1.9 mcg/dL) and inappropriately normal adrenocorticotropic hormone (ACTH) (34 pg/ml), low serum free testosterone (<2.5 ng/dL), low luteinizing hormone (0.7 mIU/ml), low follicular stimulating hormone (< 2.6 mIU/ml), low free T4 at 0.4 ng/dL. and inappropriately normal thyroid-stimulating hormone (TSH) at 2.77 uIU/mL. Serum prolactin was mildly elevated at 86.8 ng/mL. Angiotensin-converting enzyme level was within the normal range at 33 U/L. A diagnosis of panhypopituitarism was made. Brain MRI revealed a 3 cm mass in the suprasellar region involving the hypothalamus and bilateral optic tracts with a mass effect on the anterior third ventricle. No discrete pituitary or stalk lesion was identified. A ventriculostomy tube was placed for developing hydrocephalus. A biopsy of the suprasellar mass revealed non-caseating granuloma, confirming neurosarcoidosis. Treatment was initiated with high-dose IV corticosteroids to manage secondary adrenal insufficiency and neurosarcoidosis. He was also started on IV desmopressin and IV levothyroxine to manage his diabetes insipidus and central hypothyroidism. He was transitioned to oral therapy upon discharge. Panhypopituitarism secondary to neurosarcoidosis is a rare presentation that can occur due to the infiltration of the pituitary gland or the infiltration of the hypothalamus affecting the hypothalamic-pituitary axis. Neurosarcoidosis should be considered a differential when evaluating patients with symptoms consistent with panhypopituitarism. Prompt diagnosis and initiation of corticosteroids and deficient hormones can be lifesaving.

Keywords: central hypothermia; diabetes insipidus; hypothalamo-pituitary sarcoidosis; neurosarcoidosis; panhypopituitarism.

Figure 1. Coronal T1 post-contrast MRI pituitary showing a multilobulated compressing mass within the inferior third ventricle, hypothalamus, and optic chiasm