Fig. 3
The hematoxylin–eosin (HE) staining of one recurrent metastatic lymph node with squamous dedifferentiation dissected in reoperation and the pre-reoperation I131 SPECT image. The squamous dedifferentiation component locates at the edge of this metastatic lymph node (red arrow) (a) The squamous dedifferentiation component (red arrow) is completely detached and separate from the classic PTC metastasis component (blue arrow) in the metastasis lymph node (b) The metastatic lymph node (red cross) persistently present RAI-avid character in the post-therapy. 131I WBS with SPECT after 2 courses of RAI therapy (150 + 200 mCi), the uptake in central neck around the trachea is the local remnant in thyroid bed (c)