Ultrasound-based clinical prediction rule model for detecting papillary thyroid cancer in cervical lymph nodes: A pilot study

J Clin Ultrasound. 2016 Mar-Apr;44(3):143-51. doi: 10.1002/jcu.22309. Epub 2015 Sep 24.


Purpose: To identify sonographic features of cervical lymph nodes (LNs) that are associated with papillary thyroid cancer (PTC) and to develop a prediction model for classifying nodes as metastatic or benign.

Methods: This retrospective study included the records of postthyroidectomy patients with PTC who had undergone cervical ultrasound and LN biopsy. LN location, size, shape, hilum, echopattern, Doppler flow, and microcalcifications were assessed. Model selection was used to identify features associated with malignant LNs and to build a predictive, binary-outcome, generalized linear mixed model. A cross-validated receiver operating characteristic analysis was conducted to assess the accuracy of the model for classifying metastatic nodes.

Results: We analyzed records from 71 LNs (23 metastatic) in 44 patients (16 with PTC). The predictive model included a nonhomogeneous echopattern (odds ratio [OR], 5.73; 95% confidence interval [CI], 1.07-30.74; p = 0.04), microcalcifications (OR, 4.91; 95% CI, 0.91-26.54; p = 0.06), and volume (OR, 2.57; 95% CI, 0.66-9.99; p = 0.16) as predictors. The model had an area under the curve of 0.74 (95% CI, 0.60-0.85), sensitivity of 65% (95% CI, 50% to 78%), and specificity of 85% (95% CI, 73% to 94%) at the Youden optimal cut point of 0.38.

Conclusions: Nonhomogeneous echopattern, microcalcifications, and node volume were predictive of malignant LNs in patients with PTC. A larger sample is needed to validate this model.

Keywords: fine-needle aspiration biopsy; lymph nodes; metastasis; predictive model; thyroid cancer; ultrasonography.

MeSH terms

  • Carcinoma / pathology*
  • Carcinoma, Papillary
  • Decision Support Techniques*
  • Female
  • Humans
  • Lymph Nodes / diagnostic imaging*
  • Lymphatic Metastasis
  • Male
  • Middle Aged
  • Neck
  • Pilot Projects
  • ROC Curve
  • Retrospective Studies
  • Sensitivity and Specificity
  • Thyroid Cancer, Papillary
  • Thyroid Neoplasms / pathology*
  • Ultrasonography / methods*