Original researchThe significance and the predictive factors of microscopic lymph node metastasis in patients with clinically node negative papillary thyroid cancer: A retrospective cohort study

- We investigated clinically node negative patients without RI treatment.
- We analysed the predictive factor of node metastasis with cN0 PTC patients.
- Prognostic meaning of pN1b was often found in the elders with larger PTC indicating the necessity for adjuvant treatment.

BackgroundThe management of pathological lateral node involvement (pN1b) from papillary thyroid cancer (PTC) are controvertial.MethodsA consecutive series of 246 patients, diagnosed with clinically node negative (cN0) PTC who had undergone surgery with prophyractic lateral node dissection, and without postoperative radioactive iodine administration from 2001 to 11, were reviewed to clarify the significance of pN1b.ResultsEighty-five (35%) patients had pN1b disease. One-half and 30% had pN1b in younger (age less than 45) and older patients (age 45 or over), respectively. Tumor size (≥21 mm) could predict pN1b disease in older patients. Patients with pN1b disease recurred more frequently (9 cases, 10.6%) than those without (4 cases, 2.4%), and 2 cases with pN1b died of the disease.ConclusionspN1b disease was commonly found in patients with PTC even when they were diagnosed clinically as node negative. pN1b disease with prognostic meaning was often found in the older patients with larger PTC indicating the necessity for adjuvant treatments.