New Score for Risk Stratification and Sub-classification of Bethesda III Thyroid Nodule for Optimum Management; CUC Score (Cytological, Radiological, and Clinical Scoring System)

Background: Thyroid swelling is a common clinical problem. The Bethesda classification of FNAC of the thyroid swelling is very helpful in decision making and choosing the optimum management policy. However, Bethesda III is still a problem with a wide recommendation in the management. Histologically, Bethesda III is a heterogeneous group with considerable cytological variations that proved to be of variable malignant risk. Accordingly, there is a need to subcategorize the Bethesda III into subgroups of variable malignant risk and clear recommendation in the management in order to avoid unnecessary surgery or omit necessary one. Materials and Methods: The study assumed a score system that includes the cytological and ultrasongraphic features in addition to the clinical risk factors in the assessment and getting subcategories for Bethesda III. The study is a retrospective one that was delivered from May 2016 to January 2019. The cytological features were further subdivided into follicular lesion of undetermined significance or atypia of undetermined significance, while the ultrasound features were standardized by TIRABS. The patients were also assessed for the age, gender, and family history of thyroid cancer, in addition to the red flag sings in the clinical data The latter includes hard consistency, fixed nodule, and or rapid growth or recent onset of the swelling within four to six months. The patients were classified according to the CUC (cytological, ultrasongraphic & clinical) score into three groups; group CUC I; which includes patients with score three or less. Group CUC (2) includes patients with score four or five, and group CUC (3) which includes patients with score six or more. The study assessed the malignant risk in each group. Results: Five hundred and sixty-nine (569) patients were presented in the study and with Bethesda III constituted 23% (131/569). (9/131) Patients (7%) with Bethesda III were sent for repetition of FNAC and 18% (24/131) were observed. While 106 (81%) patients sent for surgery. The total cases with reported malignancy after thyroidectomy were 14 patients (13%). The malignant cases were two (5.5%) in CUC (1) group and four cases (9.5%) in CUC (2) and eight cases (28%) in group CUC (3). On comparisons the three groups, a significant difference was present in the rate of malignancy. Group CUC (3) has the highest risk for malignancy with five folds more than group CUC (I) and three folds more than group CUC (2). Conclusion: CUC score is a scoring system that utilizes the cytologic and ultrasongraphic features in addition to the demographic & clinical characteristics in determining the malignant risk and sub-categorized Bethesda III. The score provides three groups with variable malignant risk and management policy. CUC (1) group (low risk group) had the lowest malignant risk (5.5%) where ultrasound follow up is recommended as management policy. The CUC (2) groups (intermediate risk group) had an intermediate risk (9.5%) where cytological follow up by repletion of FNAC is recommended. While CUC (3) (high risk group) carries the highest risk (28%) and surgical treatment is recommend.