Diagnosing Midline Neck Masses: Comparing Clinical Exam, the SIST Score, and the 4S Algorithm.

Objective: To validate and compare novel ultrasound scoring systems for dermoid cysts and thyroglossal duct cysts among pediatric patients.

Study Design: Retrospective study.

Setting: Tertiary care children's hospital.

Methods: An electronic medical record query of patients younger than 18 years old who underwent primary excision of a neck mass between January 2005 and February 2022, who underwent preoperative ultrasound, and had final histopathologic diagnosis of either thyroglossal duct cysts or dermoid cysts. This generated 260 results, of which 134 patients met the inclusion criteria. Charts were reviewed for demographic data, clinical impressions, and radiographic studies. Radiologists blindly reviewed ultrasound for SIST score (septae + irregular walls + solid components = thyroglossal), and 4S algorithm (Septations, depth relative to Strap muscles, Shape, Solid parts). Statistical analyses were performed to determine the accuracy of each diagnostic modality.

Results: Of 134 patients, 90 (67%) had a final histopathologic diagnosis of thyroglossal duct cysts, and 44 (33%) were dermoid cysts. The accuracy of clinical diagnosis was 52%, and preoperative ultrasound report accuracy was 31%. The 4S and SIST accuracies were each 84%.

Conclusion: Both the 4S algorithm and SIST score provide increased accuracy of diagnosis relative to standard preoperative ultrasound assessment. Neither scoring modality was determined to be superior. Further research is warranted in improving the accuracy of preoperative assessments for pediatric congenital neck masses.