A case series of ultrasound and pathological assessment of follicular thyroid tumors: Addressing indeterminate malignancy.

Rationale: Follicular tumors with uncertain malignant potential of the thyroid are a new classification of thyroid tumors in the World Health Organization (2017). Only a few cases of evaluating the value of ultrasound combined with pathological examination in diagnosing follicular tumors with uncertain malignant potential of the thyroid have been reported in recent decades.

Patient concerns: A retrospective analysis was performed on 18 patients with follicular tumors with uncertain thyroid malignant potential who underwent preoperative ultrasonography and were confirmed by operation and pathology in our hospital from January 2019 to November 2024. Ultrasonic characteristics, histopathology, and immunohistology were recorded.

Diagnoses: The patient was pathologically diagnosed as follicular tumor of uncertain malignant potential.

Interventions: All the 18 patients underwent ultrasound, surgical treatment and immunohistochemical staining in our hospital.

Outcomes: The patients underwent surgery. There was no complication or recurrence.

Lessons: This case series indicates that the ultrasonographic manifestations of follicular tumors with uncertain thyroid malignant potential were regular and well-defined hypoechoic thyroid masses with an elastic grade of 2. The pathological characteristics were positive expression of P53, TG, CD56, Ki67, TTF-1, and Gal-3 mutations in most lesions.