Inflammatory Myofibroblastic Tumor in the Thyroid Gland: A Retrospective Case Series Study and Literature Review

Abstract

Background: The objective of this study was to investigate the clinical characteristics, diagnosis, and treatment of inflammatory myofibroblastoma tumor (IMT) in the thyroid gland. Methods: A total of 17 patients with IMT by pathology from 2010 to 2020 were included in this study. Clinical features, imaging features, treatment, and prognosis were analyzed in this retrospective study. Results: The case series comprised 5 males and 12 females, with an average age of 49.6 ± 15.36 years. The patients were divided into two cohorts: with IMT without further pathological changes and with further pathological changes of the thyroid gland (e.g., nodular goiter or autoimmune thyroid disease). No significant differences were detected in tumor size and extrathyroid extension between the two groups. Fine needle aspiration biopsy examination before the operation was performed in 2 cases, and rapid freezing pathology examination during the operation was performed in 7 cases. Ultrasound images of 5 cases with only one type of pathology, IMT, presented a high and intermediate risk of malignancy. In the other 11 cases with further pathological changes of the thyroid gland, the image could be very low risk of malignancy or benign feature. Only 2 cases showed a high risk of malignancy ultrasound features. 5/17 patients underwent preventive cervical lymph node dissection additional to thyroid surgery. None of the lymph nodes were confirmed positive by postoperative pathology. Thyroid ultrasound, computed tomography scan of the lungs, abdomen ultrasound, and thyroid function tests were routine follow-up tests. During the follow-up period of 26–141 months, 2 cases were lost, and remaining 15 cases had no recurrence or metastasis and were considered cured. Conclusion: IMT in the thyroid gland is a rare disease with a good prognosis and surgical resection is the preferred treatment.