Platelet to lymphocyte ratio in differentiation of benign and malignant thyroid nodules

Aim: Differentiation of thyroid nodules, either as benign or malignant, is a real diagnostic challenge. Inflammation has an important role in development of the malignancy. Therefore, inflammatory markers are associated with malignant thyroid nodules. Platelet /lymphocyte ratio (PLR) is also one of the novel inflammatory indices derived from hemogram tests. We hypothesized whether PLR was associated with malignant thyroid nodules. For this purpose, we compared PLR levels of the patients with benign thyroid nodules to the PLR of the subjects with malignant nodules. Methods: The subjects who visited outpatient internal medicine clinics of our institution with a diagnosis of thyroid nodule were enrolled to the present retrospective study. According to the examination of the fine needle aspiration cytology (FNAC) specimen of the nodules, patients grouped into benign or malignant nodule groups. PLR of groups were compared. Results: Median PLR values of the benign and malignant thyroid nodule groups were 106 (48-432) % and 119 (48-365) %, respectively (p=0.001). PLR value higher than 106% has 69% sensitivity and 51% specificity in detecting malignant nodules (AUC: 0.59, p=0.001, 95% CI: 0.54-0.65). PLR was positively correlated with TSH level (r=0.10, p=0.34). Conclusion: We suggest that elevated PLR could be an additional tool to differentiate malignant thyroid nodules from benign ones in supportive of sonography, scintigraphy and cytology.