Endocrine Abstracts

Hyperthyroidism is rarely associated with malignancy. Some cases of co-existing between hyperthyroidism and thyroid carcinoma have been described. We report a case of association of a toxic thyroid nodule and papillary microcarcinoma.

Observation: A 50-year-old male was referred to the endocrinologist for hyperthyroidism (TSH: 0.01 mUI/l, FT4: 22.8 pmol/l, FT3: 17.1 pmol/l). Thyroid ultrasonography showed a nodule of 38 mm in the left lobe. 99 mTc thyroid scintigraphy imaging showed a hot area corresponding to the nodule with lower uptake in the remaining thyroid tissue. After return to euthyroidism with methimazole treatment, a total thyroidectomy was performed. Histopathological examination of the nodule revealed papillary microcarcinoma of 1 mm. Levothyrox treatment was prescribed without adjunct iodine therapy or lymph node dissection.

Comment: The association between hyperthyroidism and thyroid carcinoma is no longer exceptional. Some cases of Graves’ disease (1) and toxic multinodular goiter (2) and autonomously hyperfunctioning thyroid nodule (3) associated with thyroid carcinoma have been described. Our observation supports the hypothesis of non-protection of hyperthyroidism against thyroid carcinoma. The association of the two pathologies is therefore possible.

References: 1. Leghlimi S. et al., Association between Graves’ disease and differentiated thyroid carcinoma. Annals of Endocrinology, Vol 75, Issues 5–6, october 2014.

2. Marcello M. et al., Anaplastic carcinoma and toxic multinodular goiter: an unusual presentation. Eur Thyroid J. 2014 Dec; 3(4): 278–82

3. Lima M.J. et al., Autonomously hyperfunctioning cystic nodule habouring thyroid carcinoma- Case report and literature review. Int J Surg Case Case Rep. 2018;42:287–289