Neurosarcoidosis and the Pituitary

Abstract

Abstract Background: Sarcoidosis involves the nervous system in 3-10% of cases. Neurosarcoidosis (NS) can mimic other diseases, leading to delay in diagnosis and management. We present 2 cases of hypothalmo-pituitary (HP) NS with widely differing initial presentations. Case Presentations: Case 1: A 58 year old African American (AA) male presented with decreased libido and hot flashes of 8-10 months duration. He also reported headaches, pain in the face and behind the eyes and dyspnea on exertion. On evaluation, he had central hypogonadism. MRI brain showed thickening and enhancement of pituitary infundibulum (PI). CT chest showed lung lesions and bilateral hilar adenopathies. EBUS with biopsies of lung and hilar lymph node showed non caseating granulomas (NCG). He was started on Prednisone and testosterone leading to symptomatic relief. However, he stopped prednisone after 3 months due to weight gain. He was then started on azathioprine. 9 months later, he presented with recurrence of neurologic symptoms and weight loss of 30 lbs. Labs showed new findings of low prolactin, low IGF-1, central hypothyroidism and central adrenal insufficiency (AI). MRI pituitary showed diffuse thickening of 3rd and 5th cranial nerves and of PI. He was re-started on Prednisone and levothyroxine (LT4) was started with improvement of symptoms. Plan was to start him on Infliximab instead of Azathioprine. Case 2: A 26 year old AA female presented with near syncope and visual impairment in the left eye that started a few weeks prior. Testing showed superior visual field loss and evidence of optic neuropathy, disc edema with mild dyschromatopsia in the left eye. She had had polyuria and polydipsia for the preceding 2-3 months and amenorrhea for 2 years. Lab testing revealed hyperprolactinemia and central DI, hypothyroidism, AI and hypogonadism. Pituitary MRI revealed a suprasellar mass measuring 20 x 19 x 11 mm, displacing the optic chiasm. CT scan showed bilateral hilar lymphadenopathy and lesions in liver and spleen. EBUS and biopsy of mediastinal lymph nodes showed NCG. Patient was treated with IV steroids leading to improved vision. She was started on DDAVP and LT4 and initiated on methotrexate and prednisone on discharge. Discussion: Pituitary hormone abnormalities due to HP NS include anterior hypopituitarism, hyperprolactinemia and DI. The most common (MC) presentation is of DI. Among anterior pituitary hormone deficits, central hypogonadism is the MC. Systemic high dose glucocorticoids (GC) are the mainstay of initial treatment. Optic atrophy is the MC neuro-ophthalmologic manifestation of NS. Only 10 - 20 % of patients have been found to have biochemical improvement of HP axis in response to high-dose GC treatment. Since pituitary involvement commonly leads to permanent endocrine deficits, it is essential to recognize it early and to treat it aggressively to prevent further permanent hormonal and neurologic deficits.