A Closer Look at Taller-Than-Wide Thyroid Nodules: Examining Dimension Ratio to Predict Malignancy

Objective To evaluate nodule height-to-width ratio as a continuous variable predicting likelihood of thyroid malignancy. Study Design Retrospective cohort study. Setting All study information was collected from a single academic tertiary care hospital. Methods Subjects included adult patients with thyroid nodules who underwent thyroid surgery between 2010 and 2020. The following variables were collected: patient demographics, nodule dimensions via ultrasound, fine-needle aspiration biopsy results, and surgical pathology results. Statistical analysis included logistic regression modeling malignancy with variables of interest. We used a receiver operating characteristic curve to assess the discriminatory value of variables. Results Height-to-width ratio, as a continuous variable, was associated with malignancy (with each 0.1 increase in ratio; odds ratio [OR], 1.25; 95% CI, 1.14-1.37). The same relationship was true for height-to-length ratio (OR, 1.36; 95% CI, 1.24-1.56). The area under the receiver operating characteristic curve for height-to-width ratio was 63.7%. In line with current emphasis on the transverse ultrasound view, we determined 4 different height-to-width ratio intervals: <0.8, 0.8 to <1.0, 1.0 to <1.5, and >= 1.5. Likelihood ratios of malignancy for each interval were 0.6, 1.0, 2.3, and 4.9, respectively. Conclusion Our results support the association between greater height-to-width ratio and malignancy but suggest that a multilevel rather than binary variable improves prediction. The likelihood ratios at different intervals give a more nuanced view of how height-to-width ratio predicts malignancy. With continuing review of guidelines for thyroid nodule biopsy, it is important to consider these data for any point total attributed to shape.

Automated summary

This study aimed to evaluate the nodule height-to-width ratio as a continuous variable for predicting the likelihood of thyroid malignancy. The results showed that there is an association between greater height-to-width ratio and malignancy. By observing the changes in the ratio within different intervals, a more accurate prediction of malignancy likelihood can be achieved.