Parasitic thyroid nodules: cancer or not?

Baker et al. present the case of a 58-year old woman with thyrotoxicosis. She had undergone hemithyroidectomy 14 years earlier for a benign follicular adenoma.  Taking into account all clinical and pathological features, she was diagnosed with functional parasitic thyroid nodules in the left lateral neck, which is a rare diagnosis. The patient was given ablative radioactive iodine.  After 2 years, a diagnostic radioactive iodine scan was clear. The patient has since been followed for 7 years with no evidence of recurrence. Archived tissue from a left lateral neck thyroid nodule had recently been analysed for BRAF V600E mutation, which was negative.

The authors feel that the most likely mechanism behind the development of the functional lateral thyroid nodules seen in this case is thyroidosis due to seeding from the previous thyroid surgery.

Read full Case report at DOI: 10.1530/EDM-14-0027