Central cervical nodal metastasis from papillary thyroid microcarcinoma: pattern and factors predictive of nodal metastasis.
BACKGROUND
Although several factors are thought to predict the occurrence of lymph node metastases from papillary thyroid microcarcinoma (PTMC), the pattern of nodal metastasis has been rarely studied. We evaluated the pattern and factors predictive of central cervical metastasis from PTMC.


METHODS
Seventy-two patients with PTMC underwent total thyroidectomy and central neck dissection, including three who underwent therapeutic modified radical neck dissection. Lymph node involvement was analyzed by neck subsite, and clinicopathologic variables predictive of nodal metastasis were determined.


RESULTS
Central and lateral nodal metastases were found in 29 (40.3%) and 3 (4.2%) patients, respectively, and ipsilateral paratracheal, pretracheal, superior mediastinal, and contralateral paratracheal lymph node metastases in 27 (37.5%), 8 (11.1%), 4 (5.6%), and 1 (1.4%), respectively. Sex, age, tumor size, multifocality, bilaterality, extracapsular invasion, lymphovascular invasion, and MACIS (metastases, age, completeness of resection, invasion, size) for central node metastasis were not predictive of metastasis (P > .1). Temporary and permanent hypocalcemia was observed in 17 (23.6%) and 1 (1.4%) patients, respectively, and transient vocal fold paralysis in 1 (1.4%).


CONCLUSIONS
Despite the absence of palpable neck nodes, PTMC is associated with a high rate of central lymph node metastasis to ipsilateral and pretracheal subsites. No clinicopathologic factor predicted nodal metastasis. In patients with PTMC involving one lobe and positive nodes, neck dissection may exclude the contralateral side.
Roh
Jong-Lyel
JL
Department of Otolaryngology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Pungnap-dong, Songpa-gu, Seoul, 138-736, South Korea. rohjl@amc.seoul.kr
Kim
Jin-Man
JM
Park
Chan Il
CI
D000328:Adult; D000368:Aged; D002291:Carcinoma, Papillary / Q000556:secondary* / Q000601:surgery; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009333:Neck; D037981:Neck Dissection / Q000379:methods; D009361:Neoplasm Invasiveness; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy / Q000379:methods