Insular thyroid carcinoma in a young Moroccan man: Case report and review of the literature.

[INTRODUCTION] Insular thyroid carcinoma (ITC) was defined as a rare malignant thyroid cancer standing in an intermediate position between the well-differentiated (papillary and follicular) and the anaplastic thyroid carcinomas. The incidence was estimated around <1% and 10% worldwide. Despite its rarity, it remains the main cause of death from non-anaplastic follicular cell-derived thyroid cancers.

[CASE PRESENTATION] A 27-year-old single male admitted for a history of a thyroid nodule and intrathoracic extension; with local mass effect, deviating the brachiocephalic trunk to the right. He underwent a total thyroidectomy. Histopathological examination showed a poorly differentiated insular thyroid carcinoma. Radioactive iodine-131 therapy was administred at a dose of 100 mCi, and the patient was maintained on TSH-suppressive therapy. Ultrasensitive Thyroglobulin measurement after thyroxine withdrawal, taken 2 years after radioactive iodine treatment was undetectable as well as thyroid antithyroglobulin antibodies.

[CONCLUSION] Our clinical case would enrich the global registry of insular thyroid carcinomas' cases. The main challenge is early detection, aggressive intervention, and close follow-up of affected patients. The advancement in ultra-deep sequencing technologies, will contribute in the development of novel targeted therapies aiming to reduce morbidity and mortality and improve the outcomes in PDTC patients as well.