Panhypopituitarism Secondary to Neurosarcoidosis with Superimposed Mycobacterium Nebraskense Meningitis

Neurosarcoidosis (NS) is a severe manifestation in 5-15% of sarcoidosis cases. Complications can involve both the central and peripheral nervous system. The most common manifestations are cranial neuropathy and aseptic meningitis. In the setting of hypothalamic or pituitary involvement, patients may present with neuroendocrine dysfunction. In this case report we describe a patient who presented with panhypopituitarism in the setting of neurosarcoidosis as well as superimposed Mycobacterium nebraskense infection.

Case Description:

75 year-old female with past medical history of hypertension, diabetes, and hyperlipidemia presented with dizziness, unintentional weight loss, and memory impairment. Vitals signs significant for orthostatic hypotension and bradycardia. Physical exam positive for gait instability, bitemporal hemianopsia, and cachexia. MRI of the brain showed an infiltrative clival tumor invading the pituitary gland, extending into the optic chiasm and along cisternal segment of right trigeminal nerve. Abdominal CT revealed diffuse portahepatic and gastrohepatic lymphadenopathy. Biopsy of celiac node and clival mass significant for rare foci of both non-necrotizing granuloma with superimposed Mycobacterium nebraskense infection. Neurosarcoidosis diagnosis confirmed with elevated ACE level. Hormone testing was notable for central panhypopituitarism. Prolactin was mildly elevated to 25.5 ng/ml, reflecting potential stalk effect. Follicle stimulating hormone < 0.3 mUnits/ml, leutinizing hormone < 0.1 mUnits/ml indicating central hypogonadism. Thyroid stimulating hormone (TSH) < 0.008 pg/nl and free T4 1.8 ng/dL demonstrating central hypothyroidism. Cortisol levels were depressed in response to dexamethasone given for mass effect. Was started on levothyroxine and hydrocortisone for treatment. During hospitalization, patient developed progressive encephalopathy and low-grade fever. These were attributed to atypical Mycobacterium nebraskense infection, which was treated with linezolid, rifampin, azithromycin, and moxifloxacin. Eventually the patient was weaned off steroids and encephalopathy improved.

Discussion:

Neurosarcoidosis is an uncommon and severe presentation of sarcoidosis. In rare cases it is known to cause neuroendocrine dysfunction. A 2003 prospective study showed that neurologic involvement may be more common that previously reported. Given the drastic improvement that some patients have with corticosteroids, we believe formal neuroendocrine testing should not be delayed in patients with sarcoidosis. Recent literature regarding prevalence of neurosarcoidosis is still limited.