Diagnostic value of modified systemic inflammation score for prediction of malignancy in patients with indeterminate thyroid nodules

Background: Approximately 20% of the thyroid biopsies render an indeterminate (ID) cytology. We evaluated the diagnostic value of preoperative modified systemic inflammation score (mSIS) in predicting the malignancy of ID thyroid nodules (TNs).

Methods: Data of 162 patients with indeterminate TNs were examined retrospectively. The mSIS was calculated as follows: mSIS 0 [patients with albumin (ALB) ≥ 4.0 g/dL and lymphocyte-to-monocyte ratio (LMR) ≥ 3.4], mSIS 1 [ALB < 4.0 g/dL or LMR < 3.4], and mSIS 2 [ALB < 4.0 g/dL and LMR < 3.4].

Results: Patients were classified into mSIS 0 (n = 105), mSIS 1 (n = 34) and mSIS 2 (n = 23) groups. The malignancy rates for the mSIS 0, 1 and 2 groups were 34.3%, 64.7% and 100% respectively. Preoperative mSIS was significantly associated with the presence of thyroid malignancy (p < 0.001).

Conclusions: If the mSIS of patients with ID cytology is 1 or 2, appropriate surgical treatment should be performed without delay, due to the increased risk of malignancy.

Keywords: Albumin; Lymphocyte-to-monocyte ratio; Systemic inflammation score; Thyroid cancer; Thyroid nodules.