Two cases of Graves’ disease with presentation of unilateral diffuse uptake of radioisotopes

Abstract

We present two cases of Graves' disease whose initial thyroidal scintiscan with 99mTcO4- (Case 1) and 123I (Case 2) showed unilateral diffuse uptake of radioisotopes. Initial diagnosis was possibility of malignancy in Case 1 and Graves' disease or Plummer's disease in Case 2. Both cases underwent right hemithyroidectomy. Histopathology of the resected thyroid gland in both showed hyperplastic columnar epithelium and infiltrative lymphocytes which was compatible with Graves' disease. Twenty seven (Case 1) and eight months (Case 2) after operation, both presented with thyrotoxic symptoms associated with enlarged left lobe, increased serum free thyroid hormone concentrations, suppressed TSH concentration, increased thyroidal 123I uptake in the remaining left lobe, and positive thyrotropin receptor antibodies. Both cases were successfully treated with methimazole. It was concluded that initial radioisotope uptake as well as scintigram in rare subgroup of patients with Graves' disease could be similar with that of non-autoimmune autonomous goiter (Plummer's disease).

Graves' Disease Affecting one Thyroid lobe (Unilateral Graves' Disease): Case Report

“…In 1993, Sakata and his colleagues (8) reported two patients with Graves' disease with unilateral uptake of isotope on Tc99m scan in one patient and on I-123 scan in the other. Both were treated by right hemithyroidectomy and after 27 and 8 months respectively, recurrent thyrotoxic symptoms occurred with enlargement of the remaining left lobe in both patients, it showed intense I-123 uptake in thyroid scan and both were controlled medically (4) .…”

First Reported Case of Unilateral Graves' Disease in the Left Lobe of a Bilobar Thyroid Gland

“…There are only a handful of case reports of unilateral Graves' disease not caused by thyroid hemiagenesis available in the medical literature. Each case described involved a hyperfunctioning right thyroid lobe (1)(2)(3)(4). In this report we describe a case of unilateral Graves' disease involving the left thyroid lobe of a bilobar gland, summarize the cases in the medical literature to date, and discuss the possible pathophysiology behind unilateral Graves' disease.…”

Asymmetrical Graves’ disease in children: potential usefulness of potassium iodide monotherapy

“…GD usually presents as a diffuse hyperthyroid goitre involving both lobes of the thyroid. There are also reports of a rare form of GD termed ‘unilateral GD’, in which iodine uptake is normal in one lobe and elevated in the other lobe 8–11. Interestingly, most unilateral GD cases involve the right lobe 11.…”

“…GD typically presents as a diffusely hyperfunctioning goitre involving both lobes of the thyroid gland. Much less frequently reported is unilateral or asymmetrical GD, with increased iodine uptake in one lobe and normal uptake in the other lobe or unequal increases in iodine uptake in each lobe 8–12…”