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I recently saw a 25 year old male law student with hyperthyroidism. He came with a diagnosis of Graves disease made about 3 years previously (solely on clinical grounds as far as I can tell). He was treated with PTU with control of symptoms for about 1 and 1/2 year after which he stopped the drug. His hyperthyroidism returned over the course of several weeks to a few months. When he presented 2 months ago, he had been of the PTU about a year and was symptomatically hyperthyroid. The hyperthyroidism was interfering with his law studies. He was tachycardic, diaphoretic and tremulous on exam. His thyroid was twice enlarged and diffusely so. No nodules were appreciated, although on serial exams there does appear to be some inhomogeneity in the texture of the gland. His thyroid function tests showed and undetectable TSH <0.01 and and elevated FT4 of 3.2 and a elevated Total T3 of 250. I discussed options with him regarding treatment and he decided to consider I131 but wanted to restart PTU for now. I convinced him to obtain a I123 study to calculate a dose for I131 and confirm the Graves diagnosis. He delayed and only did the I123 after 2 to 3 weeks of PTU therapy and improvement in his symptoms. I took him off the PTU for 2 weeks (after the 3 week therapy) and obtained the I123 scan. His 6 and 24 hour uptakes were at the upper limits of normal. 33% or so at 24 hours. The scan showed heterogeneous uptake. Antimicrosomal (antiTPO) antibodies were strongly positive but a TSI assay was negative. I thus have two questions- 1. Diagnoisis - is this patient's diagnosis atypical Graves, a variant of toxic multinodular goiter, Graves with in a multinodular goiter, transition from Hashimoto's to Graves? 2. What would be the best course of therapy? Would I-131 be beneficial?
Thanks very much for any insight.
Coleman Gross, MD
Specialty Clinics
University Health Service
Tang Center
2222 Bancroft Way
Berkeley, CA 94720
Response
The clinical picture is certainly most compatible with Graves, in view of the rapid relapse, youth, male sex, non-lumpy gland, and + TPO-Ab. I suppose a toxic multinodular goiter might present this way, but it would be unusual. A non-homogenous scan is not rare, probably because of the variable extent of coexistent thyroiditis in various parts of the gland. Obviously an US might be informative, but I do not think you really need it if you can feel the gland and do not feel lumps. Since he relapsed from one course of ATD, he probably would do so again. Thus I believe most thyroidologists would offer RAI as the next therapy, and I do not see any contraindication from what you report. If you have a capable surgeon available, surgery is also reasonable to consider, especially if he has significant ophthalmopathy.
Leslie J De Groot,MD