Papillary Thyroid Carcinoma with Toxic Multinodular Goiter: A Case Report and Literature Review

Abstract

Aims: Papillary thyroid carcinoma (PTC) is the most common variant of thyroid carcinoma (TC). TC usually occurs in euthyroid states. We discuss a rare case of co-existence of PTC with hyperthyroidism in a patient having toxic multinodular goitre (TMNG). Presentation of Case: A 37-year-female presented with thyroid swelling for 6years. Initially size was static and confined to left lobe then progressed to involve entire thyroid (last 2years). Symptoms of hyperthyroidism and hoarseness of voice (last 1year) were present along with bilateral exophthalmos (last 2months). She was on Tab carbimazole (for 1year) and Tab propranolol (for 7months). On examination 16x10cm, firm, bosselated, well defined, thyroid swelling having palpable thrill over upper pole was present. Dalrymple’s sign was also present. High Resolution Ultrasonography (HRUSG) Neck showed diffuse thyroiditis with multinodular goitre. Blood biochemistry showed hyperthyroidism (FT3-6.15, FT4-6.99, TSH-0.39). Fine Needle Aspiration Cytology done twice suggestive of Colloid goitre with cystic degeneration (Bethesda category II) and atypia of undetermined significance (category III) respectively. Diagnosis of TMNG with thyroid ophthalmopathy was made. Total thyroidectomy was done. Histopathology report showed right lobe Papillary Thyroid Cancer with left lobe adenomatous goitre. In follow-up of 2 years, patient is asymptomatic and doing well on thyroxin supplementation. Discussion and Conclusion: The somatic mutations in the Thyroid Stimulating Hormone (TSH) receptor genes of cancer cells might account for hyperthyroidism caused by thyroid carcinoma. This case highlights the need for a comprehensive evaluation to rule out cancer, especially in a hyperthyroidism-related clinical context.