Risk factors of SMLN metastasis as identified in previous studies are contralateral lateral neck LN metastasis, central lymph node (CLN) metastasis, extensive CLN metastasis, contralateral CLN metastasis, direct extension to SMLN, grossly perithyroidal extension (PTE), medullary or poorly differentiated carcinoma, distant metastasis, and Hurtle cell carcinoma[5 –10 ].
Source: wiktionary