Endocrine Abstracts

Introduction: Graves’ disease (GD) has been related to a higher incidence of thyroid cancer. Thyroid nodules found in GD seem to have a higher risk for malignancy. The prognosis of thyroid cancer may be aggravated by the association with GD.

Case report: We present the case of N.I, a 56-year-old woman diagnosed with multinodular goitre and overt hyperthyroidism for which therapy with carbimazole 40 mg/day was started. She was referred to our Endocrinology Department 2 months later for follow-up. She complained of important weight loss, palpitations, fatigability and recent swelling of the neck. Clinical examination revealed a painless large goitre and mild exophthalmia. Laboratory findings still showed subclinical hyperthyroidism (TSH=0.013 μUI/ml – normal range 0.4–4 and FT₄=0.957 ng/dl – normal range 0.89–1.76). TSH antibodies (TSAb) were present in high titres and GD diagnosis was established. Thyroid ultrasound revealed a large conglomerate mass with microcalcifications in the left lobe on the background of a hypoechoic, hypervascular goitre. FNAB from the nodule revealed cytology highly suspicious of malignancy. Total thyroidectomy was performed and histopathology report showed invasive papillary thyroid carcinoma follicular variant and typical findings of GD. After surgery, the patient underwent radioactive iodine (¹³¹I) therapy. The post-therapy whole-body radioiodine scan showed remnant thyroid tissue and multiple iodine-avid lung metastases. Thyroglobulin levels remained abnormally elevated, making the patient a candidate for an additional radioactive iodine administration.

Conclusions: This is a rare case of simultaneously diagnosed GD and thyroid carcinoma. The tumour had a rather invasive and aggressive phenotype, in contrast to histopathology and in accordance with studies proposing GD as a negative prognostic factor in thyroid cancer. We suggest managing patients with thyroid cancer and GD according to high-risk protocols. We recommend a closer ultrasound follow-up for nodules in GD and the performance of FNAB when nodules are found.