Endocrine Abstracts

Introduction: Endocrinopathy is frequently seen in systemic amyloidosis and commonly involves thyroid and gonads. We report a case of primary adrenal failure secondary to systemic light chain amyloidosis (AL), involving kidney, liver, spleen, gut, nerves and tongue.

Case: A 42-year-old Somalian lady presented with 2-year history of lethargy, febrile episodes and 21 kg weight loss. Investigations showed increase in serum lambda light chain 103 mg/l (5.7–26.3), paraproteinaemia (7 g/l), 8% plasma cells on bone marrow aspirate and a diagnosis of lambda light chain secreting plasma cell dyscrasia was made. She subsequently developed renal failure and renal biopsy confirmed systemic amyloid light chain (AL) amyloidosis. CTDa chemotherapy (attenuated cyclophosphamide, thalidomide, dexamethasone) was initiated. She further developed macroglossia, peripheral and autonomic neuropathy and altered bowel habits. Amyloidosis was further confirmed on duodenal biopsy and serum amyloid protien (SAP) scintigraphy, demonstrating moderate total body amyloid load including liver and spleen.

Two years later, she was admitted following cardiac arrest from neutropaenic sepsis and renal failure requiring external cardio-pulmonary support. Hypotension did not resolve (mean BP: 76/44 mmHg) despite overall recovery through resolution of sepsis and renal failure (haemodialysis). Hypoadrenalism was clinically suspected and was confirmed through short synacthen test (60 min cortisol response: 128 nmol/l). Hypotension resolved (Mean BP:126/80 mmHg) on parenteral hydrocortisone (400 mg/day) and oral fludrocortisone (50 μg/day).

Progress: A normal pituitary scan and an appropriate pituitary response (IGF1 16.3 (13–37 nmol/l), LH <1 (2–12 IU), FSH <1 (2–10 IU), TSH 1.05 (0.35–6 mU/l), T₄ 13.5 (9–26 pmol/l), ACTH 17.4 (<46.1 ng/l), prolactin 881 (<600 mu/l)) ruled out secondary hypoadrenalism. She is haemodialysis dependent and is currently stable on oral hydrocortisone (20 mg/day) and fludrocortisone (50 μg/day).

Conclusion: Diagnosis of adrenal insufficiency can be challenging in critically ill patients diagnosed with conditions involving multiple organs, such as systemic amyloidosis. High degree of clinical suspicion is needed to prevent this potentially fatal condition, as endocrine dysfunction in systemic amyloidosis is more frequent than it was once thought.