Recurrent Graves' hyperthyroidism after prolonged radioiodine-induced hypothyroidism.

Area of Science:

• Endocrinology
• Nuclear Medicine

Background:

• Radioactive iodine (RAI) therapy is a cost-effective treatment for Graves' disease (GD).
• Post-RAI hypothyroidism typically prevents disease recurrence.
• This report details an unusual case of recurrent thyrotoxicosis after a period of hypothyroidism.

Purpose of the Study:

• To present an unusual case of recurrent hyperthyroidism following radioactive iodine therapy for Graves' disease.
• To emphasize the need for continued surveillance in patients treated with RAI.

Main Methods:

• Clinical case presentation.
• Review of laboratory findings, including thyroid-stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3).
• Analysis of radioactive iodine uptake and scan results.
• Description of patient management, including initial treatment and levothyroxine therapy.

Main Results:

• A 48-year-old male presented with symptoms of hyperthyroidism, including palpitations and weight loss.
• Initial laboratory tests revealed suppressed TSH and elevated FT4 and FT3 levels.
• The patient developed hypothyroidism post-RAI therapy, treated with levothyroxine, but experienced recurrent hyperthyroidism two years later.

Conclusions:

• Recurrent hyperthyroidism after achieving post-RAI hypothyroidism is uncommon in Graves' disease.
• This case underscores the necessity of long-term monitoring for patients undergoing RAI treatment.
• Continued surveillance is crucial for early detection of recurrent thyrotoxicosis.