SUN-177 A Silent Bomb: A Case of Severe Primary Adrenal Insufficiency in the Context of Adrenal Metastatic Disease

Background: Adrenals glands are the most commonly involved endocrine organ in cancer metastasis due to its abundant lymphatic communication and blood supply. Up to 4% of non-small-cell lung cancers and 71% of lymphomas have bilateral adrenal metastasis. Early detection with hormone replacement can be life-saving. Clinical Case: A 58 year old male was admitted for hyperkalemia (potassium 6.4 mmol/L, range: 3.5-5.1) with prolonged PR interval on EKG, hyponatremia (sodium 131 mmol/L, range: 136-145), hypoglycemia (glucose 48mg/dl), and renal function impairment (creatinine level elevation of 1.38 mg/dl from a baseline of 0.94 mg/dl). He had been diagnosed with Stage IVb non-small-cell lung cancer about 20 months prior, and had a known history of chemotherapy, adrenal metastasis and left adrenal gland radiation (20 G in 5 daily fractions) about 10 months ago. For the past 10 months, the patient had reported no weight loss, nausea, vomiting, or other symptoms or signs of adrenal insufficiency, apart from intermittent fatigue, which he had attributed to his lung cancer diagnosis. On review, a previous PET/CT scan showed intense FDG uptake in the bilaterally enlarged adrenal glands, measuring 3.3 x 2.8 cm on the left, and 3.1 x 1.8 cm on the right. His ACTH level was found to be elevated to 1,023 pg/ml (range: 6-63) with borderline low free cortisol level 0.06 mcg/dl (range 0.04-0.35). Aldosterone level was found to be 3.4 ng/dl (range: 4-31), with a renin level of 36.2 ng/ml/hr (range: 0.5-4). Primary adrenal insufficiency was diagnosed, and the patient was started on hormone replacement therapy, which was titrated as outpatient. Now he is continued on a regimen of hydrocortisone 15 mg and 5 mg, at 8 am and 3 pm respectively, and fludrocortisone 0.1 mg daily. In two months, his ATCH level fell from 1,023 to 89 pg/ml with normalization of kidney functions, sodium level (now 137 mmol/L) and potassium level (now 4.8 mmol/L). He gained 4 kg, and has been feeling more energetic and functional on his follow up visits. Conclusion: Patients with adrenal metastatic cancer may have atypical symptoms and signs despite having severe primary adrenal insufficiency. High risk patients should be monitored, even in the absence of symptoms, for the development of adrenal insufficiency. Reference: 1. Yamamoto, T. (2018). LATENT ADRENAL INSUFFICIENCY: CONCEPT, CLUES TO DETECTION, AND DIAGNOSIS. Endocrine Practice, 24(8), pp.746-755. 2. Angelousi A, Alexandraki KI, Kyriakopoulos G, et al. Neoplastic metastases to the endocrine glands. Endocr Relat Cancer. 2019.