Endocrine Abstracts

Introduction: Thyroid hemiagenesis is a congenital developmental disorder. Most cases are euthyroid although hyperthyroidism, hypothyroidism, and malignancy may develop. We present a case of hemiagenesis with Graves’ disease.

Case: A 45-year-old female patient was admitted to the endocrinology ward due to nausea and diarrhoea. She had hyperthyroidism for 1 year. She did not have any family member with thyroid disease. She was already on propylthiouracil therapy. She did not bear signs of Graves ophthalmopathy. Thyroid function tests revealed a TSH level of 0.01 μU/ml (0.35–4.94), free T₄ 1.80 ng/dl (0.7–1.48), free T₃ 3.82 pg/ml (1.71–3.71). TSH receptor antibody, antithyroid peroxidase antibody, and anti-thyroglobulin antibody were all positive. Left lobe and isthmus were invisible on ultrasound. Right lobe was 44×18×12 mm in size with heterogenous hypervascular paranchyme echogenicity containing no nodules. Thyroid scan using 5 mCi ^99mTc showed increased homogenous tracer uptake in the right lobe (6.7%). Isthmus, pyramidal lobe, and left lobe were not visualised. The patient was diagnosed with thyroid hemiagenesis and Graves’ disease. The dose was readjusted and RAI therapy was planned.

Conclusion: In case of unilateral increased uptake on scintiscan Graves’ disease with hemiagenesis must be kept in mind in the differential diagnosis of autonomus solitary adenoma, postinflammatory atrophy of thyroid in Hashimoto’s disease, focal or unilateral subacute thyroiditis, and primary or metastatic carcinoma. It is prudent to do thyroid ultrasound along with scintigram.