Endocrine Abstracts

Introduction: A thyroid nodule discovered in a patient with Graves’ disease (GD) should be evaluated and managed according to guidelines. A subcentimetre incidental thyroid cancer founded in a patients with GD, without high-risk history, without suspicious sonographic (US) features has not been reported yet.

Clinical case: A 40-year-old female patient, presented to our hospital with symptoms of thyrotoxicosis. On physical examination heart rate was 120 b.p.m., blood pressure of 130/90 mmHg, with a nontender thyroid gland, with murmurs on auscultation, without nodules on palpation. No exophtalmos or skin changes were noted. The patient was under treatment with methimazole 5 mg twice daily and β blocker, since 7 months. Laboratory investigations showed AST: 93 U/l, ALT: 156 U/l (n: <40 U/l). Thyroid function tests revealed free T₃: 22.52 pg/ml (n: 2–4.4), free T₄: 63.04 ng/dl (n: 10.6–19.4), and TSH: 0.003 μUI/ml (n: 0.35–4.94). TRAbs: 1.8 UI/ml (n<1). A thyroid ultrasound detected a diffuse enlargement with diffuse hypervascularity of thyroid, with a hyperechoic rounded nodule measuring 9 m÷6.4 mm in the left lobe (with regular borders, with halo, without microcalcifications) and a hypoechoic right lobe. A scintigraphy showed a increased diffuse uptake, suggestive of GD. Fine-needle aspiration biopsy (FNAB) was not performed. Our patient underwent a total thyroidectomy after 2 months, in a euthyroid state. Histopatological examination of the thyroid gland showed a focus of papillary microcarcinoma, follicular variant, lying into the nodule detected on US.

Conclusions: Thyroid cancer occurs in GD patients with a frequency of 2% or less. We referred a case of incidental thyroid cancer in a Graves’ disease with no malignant ultrasound features. We conclude that the presence of benign nodules on ultrasonographic examination does not reduce the risk of malignancy. We recommend a FNAB in all nodules detected on ultrasound in Graves’ disease and early total thyroidectomy in these cases.