The coexistence of Graves’ Disease and multifocal papillary thyroid microcarcinoma is a rare phenomenon. A retrospective case –control study (1) found that Papillary thyroid cancer (PTC) was incidentally discovered in 2% of 2356 surgically treated Graves’ disease patients. However there are no published series of metastatic multifocal PTC in patients presenting with Graves’ Disease.
We present 2 cases of metastatic multifocal PTC in young patients presenting with Graves’ Disease. Case 1 is a 24 year old woman who presented with thyrotoxicosis and classical clinical and biochemical features of Graves’ Disease (TSH Receptor antibody 38, normal <1.5IU/L). A thyroid ultrasound (arranged by GP) showed enlargement and increased vasculature in keeping with Graves’ disease. However there were also diffuse microcalcifications suggestive of PTC. Fine needle aspirates (FNA) of the thyroid gland and suspicious lymph nodes showed metastatic PTC. She proceeded to a total thyroidectomy with lymph node dissection. The histopathology confirmed multifocal, bilateral papillary microcarcinoma with lymph node metastases on background Graves’ disease. Case 2 is a 31 year old man who presented with typical Graves’ thyrotoxicosis (TSH Receptor Antibody >40IU/L) and goiter confirmed on uptake scan. He responded well to Carbimazole (normal TFTs) but after 16 months of treatment he became hypothyroid (TSH 91, normal 0.40-4.00mIU/L) and his neck examination revealed cervical lymphadenopathy. Ultrasound showed extensive microcalcification and FNA confirmed PTC. He underwent total thyroidectomy with right and central compartment neck dissection and histopathology confirmed bilateral multifocal PTC with extensive lymph node metastases.
These cases of multifocal PTC in young patients presenting with typical Graves’ Disease raise the question of whether thyroid U/S should be considered in the routine assessment of Graves’ thyrotoxicosis.