Akademik Veri Yönetim Sistemi
Endobridge, Antalya, Türkiye, 19 - 22 Ekim 2023, cilt.2, ss.5-6, (Özet Bildiri)
Inflammatory Myofibroblastic Tumor: An Extremely Rare Tumor of the Thyroid Gland Poses Challenges in Diagnosis and Management
Inflammatory myofibroblastic tumor (IMT) is an exceedingly rare mesenchymal tumor characterized by myofibroblastic spindle cells and an inflammatory cell infiltrate. Its etiology, pathogenesis, diagnosis and treatment are still unclear. Inflammation, trauma, autoimmune diseases, surgery and viral infections, abnormal healing (mainly myofibroblast proliferation) are the main factors in etiology of IMT. According to the WHO ( World Health Organization) classification, 8 cases of thyroid IMT have been reported to date. Most of the studies on thyroid IMT are in the form of case reports. The imaging features are nonspecific and ultrasound is the best examination method and can showed similar features of the thyroid cancer. The clinical presentation of IMT in the thyroid gland varies widely, ranging from an asymptomatic thyroid nodule to a diffuse, rigid, fixed, and painful or painless mass. While IMT of the thyroid gland is generally considered a benign borderline tumor with very low metastatic potential, its diagnosis and management can be intricate. Pathology and immunohistochemistry are two of the significant factors in diagnosis. The positive expression of ALK (Anaplastic lymphoma kinase), SMA (Smooth muscle actin), MSA (Muscle specific actin), and Vim (Vimentin) endorse the diagnosis of IMT and can be used to distinguish from other IMT -like neoplastic and nonneoplastic tumors that show spindle cell proliferation. Surgery remains the preferred treatment, with recurrence being rare following successful removal Nonetheless, the optimal management of residual tumors is contentious and may involve a second surgery or the use of immunosuppressants and chemotherapeutic agents.
Case:
A 47-year-old female patient presented with painless discomfort and stiffness around the thyroid gland. A neck ultrasound revealed a hypoechoic nodule measuring 21x12 mm on the left lobe and a hypoisoechoic heterogeneous nodule 35x28 mm in size on the right lobe of the thyroid gland. These nodules displayed low vascularity, and no pathologic lymph nodes were detected. Fine needle aspiration biopsies (FNABs) were performed on the nodules in both lobes at different times, indicating thyroiditis in the right lobe and spindle-shaped cells with atypia of uncertain significance in the left lobe. Subsequent evaluation of FNAB materials at a referral center suggested a high suspicion of lymphoid malignancy. The patient underwent thyroidectomy; however, the surgeon chose to preserve the left thyroid lobe due to its extreme fibrotic and stone-like consistency, thereby preserving recurrent laryngeal nerve function. Histological analysis confirmed the presence of an inflammatory myofibroblastic tumor characterized by spindle cells accompanied by abundant histocytes, plasma cells, and lymphocytes. The tumor cells exhibited positivity for SMA, Vim. Postoperative ultrasound revealed a residual tumor approximately 2 cm in size located in the left isthmus and adjacent left lobe, which remained stable over a 6-month follow-up period.
Conclusion:
Our case highlights the potential for misdiagnosing IMT of the thyroid gland as malignant thyroid tumors. Furthermore, the management of a residual tumor presents a complex clinical challenge. The surgical team is reluctant to pursue a second surgery due to potential risks to recurrent laryngeal nerve function. In this session, we aim to solicit expert opinions and engage in interactive discussions regarding the management .