Abstract 8: Thyroid amyloidosis presenting as persistent painless thyroiditis

Case Report: A 34-year-old patient with ESRF, found to have hereditary-amyloidosis, was referred with low TSH: 0.112 (0.340-4.250 micIU/mL), low FT3: 1.77 (2.40-4.20 pg/mL) and normal FT4:1.49 (0.80-2.30 ng/dL) in May 2018. Clinically asymptomatic, euthyroid and no goitre; was diagnosed “Sick-Euthyroid-Syndrome”. He underwent renal transplant in August 2018; his subsequent treatment included Prednisolone 20mg daily and immunosuppressants. On follow-up, his TSH was 0.303 in Oct 2018. Over next year, he had persistently low TSH: 0.005-0.196, with normal FT3, but elevated FT4: 2.39-5.21. His clinical-features varied from being asymptomatic to developing mild thyrotoxicosis. ESR: normal, Thyroid-antibodies negative, USG showed diffuse thyroid and repeated Technetium-99 scans revealed ‘gross thyroiditis’. He was managed on beta-blockers and ongoing Prednisolone. His health deteriorated since late 2019, with multiple episodes of pancreatitis due to pancreatic-duct-stones and stricture. He returned back in 2021 with neck-swelling; non-tender large-goitre with multiple nodules. TFT: low TSH, high FT4 and normal FT3. USG revealed bulky thyroid with few nodules; FNAC suggested Amyloid. He underwent Total Thyroidectomy; Histopathology confirmed ‘Amyloidosis’. Conclusion: Our patient had chronic painless thyroiditis and his steroid-therapy for post-transplant-immunosuppression probably masked the thyrotoxic-features. USG-thyroid indicated gradual structural changes, and TFT suggested possible impaired peripheral conversion of T4 to T3.