Case report. Isolated intrathyroid metastasis from undifferentiated and squamous carcinoma of the head and neck: the case for surgery and re-irradiation.

Metastasis to the thyroid gland is rare, with fewer than 450 cases reported in the literature. Furthermore, intrathyroid metastasis from head and neck squamous cell carcinoma (HNSCC) is even more unusual, with only nine previously documented cases. This study details the cases of three patients (from one centre) who presented with intrathyroid metastasis from HNSCC and who were treated with a combination of surgery and radiotherapy. Although previous reports have suggested that this pattern of spread is associated with a poor outcome, we are able to show that appropriately selected patients benefit from a combination of both radical surgery and adjuvant radiation therapy, even when this entails some areas of re-irradiation.