Primary thyroid leiomyosarcoma: a case report and review of the literature

Abstract

Primary thyroid leiomyosarcoma (LMS) is an extremely rare tumor. We report a case of a 47-year-old male with a rapidly growing neck mass and disfagia. Preoperative investigations were diagnostic of anaplastic carcinoma. Total thyroidectomy with partial esophagectomy and dissection of right infrahyoid muscles was performed. Through histolological and immunohistochemical evaluations a primary thyroid high-grade LMS was diagnosed. At 2 months of follow-up a local recurrence was detected and consequently the patient was submitted to chemotherapy with partial response. He is still alive 9 months after surgery. Diagnosis of primary thyroid LMS is difficult due to its similarity to other more common thyroid tumors. To date, there is no standard therapy and prognosis is poor.

Figure 1

CT scan shows the presence of a bulky right cervical mass (white arrow).

Figure 2

Elongated spindle-shaped cells arranged in fascicular pattern (H&E, ×200).

Figure 3

Tumor cells with eosinophilic cytoplasm and hyperchromatic blunt nuclei with marked anisokaryosis (H&E, ×400).

Figure 4

Local recurrence at 18F-FDG PET/CT (white arrow).

Figure 5

Local recurrence at CT scan (white arrow).