Prognostic Implications of Lymph Node Yield and Lymph Node Ratio in Papillary Thyroid Carcinoma

<p>Background: The lymph node yield (LNY) and the lymph node ratio (LNR) have been shown to be important prognostic factors in oral, colon, and gastric cancers. The role of the LNY and LNR in papillary thyroid cancer (PTC) is unclear. The aims of this study were to determine if a high LNR and a low LNY decrease disease-free survival rates. This study further aimed to determine an optimum nodal yield.</p><p>Methods: A retrospective analysis was conducted of 198 patients with PTC undergoing total thyroidectomy with neck dissection between 1987 and 2011. The LNY and LNR were adjusted by relevant covariates in a multivariate Cox regression analysis with Andersen-Gill extension.</p><p>Results: The LNR was associated with a decrease in disease-free survival (hazard ratio 3.2 [95% confidence interval 1.4-7.3], p = 0.005). Patients with an LNR of 0.30 or higher had a 3.4 times higher risk of persistent or recurrent disease compared with patients with an LNR of 0.00 ([95% confidence interval 1.1-10.5], p = 0.031). Conversely, patients with an LNR of 0.11 or lower had an 80% chance of remaining disease free during 5 years of follow-up. The LNY showed no significant independent effect and an optimum nodal yield was not determined.</p><p>Conclusions: The LNR is an important independent prognostic factor in PTC and can be used in conjunction with existing staging systems. A clinical relevant cut-off point of 0.3 (one positive lymph node out of three total) is proposed. No prognostic implications for LNY were identified.</p>

Focal Bronchiectasis Causing Abnormal Pulmonary Radioiodine Uptake in a Patient with Well-Differentiated Papillary Thyroid Carcinoma

Background. False-positive pulmonary radioactive iodine uptake in the followup of differentiated thyroid carcinoma has been reported in patients with certain respiratory conditions. Patient Findings. We describe a case of well-differentiated papillary thyroid carcinoma treated by total thyroidectomy and radioiodine ablation therapy. Postablation radioiodine whole body scan and subsequent diagnostic radioiodine whole body scans have shown persistent uptake in the left hemithorax despite an undetectable stimulated serum thyroglobulin in the absence of interfering thyroglobulin antibodies. Contrast-enhanced chest computed tomography has confirmed that the abnormal pulmonary radioiodine uptake correlates with focal bronchiectasis. Summary. Bronchiectasis can cause abnormal chest radioactive iodine uptake in the followup of differentiated thyroid carcinoma. Conclusions. Recognition of potential false-positive chest radioactive iodine uptake, simulating pulmonary metastases, is needed to avoid unnecessary exposure to further radiation from repeated therapeutic doses of radioactive iodine