Primary alveolar rhabdomyosarcoma of the thyroid

Primary thyroid sarcoma is a very rare entity, accounting for less than 1.5% of all malignant thyroid tumors. Primary thyroid rhabdomyosarcoma is extremely rare: Until now, there had been only two child cases and four adult cases diagnosed worldwide. We report herein the case of a 17-year-old female who presented with a large, rapidly growing neck mass. To the best of our knowledge, this is the first reported case of primary alveolar rhabdomyosarcoma in the thyroid. Moreover, this is the only case that shows an outstanding response of RMS in the thyroid to neoadjuvant chemotherapy. It provides an example of a potential new treatment for patients whose tumors cannot be treated surgically.