“…The etiology of primary thyroid LMS remains unclear, however, certain authors have postulated that it may originate from the smooth muscle in the vascular walls ( 6 , 10 , 14 , 16 – 18 ). In addition, LMS appears to invade adjacent tissue rather than metastasizing to regional lymph nodes ( 6 , 11 ), thus, radical surgery is essential ( 6 , 10 , 11 , 16 , 17 , 19 ). The complexity of the procedure depends on tumor size and adjacent tissue/organ involvement.…”