Primary leiomyosarcoma of the thyroid
A 56-year-old male presented with 4 months history of a rapidly enlarging left anterior neck mass, hoarseness, and dysphagia. He was referred from another city with an initial diagnosis of thyroid cancer. No comorbidities existed, and the medical history was unremarkable. A history of radiation exposure did not exist, either. Physical examination revealed a hard mass of about 3 cm in the left lobe of the thyroid gland. There were no palpable cervical or supraclavicular lymph nodes. He was clinically euthyroid. Serum thyroid stimulating hormon, serum T3 (triiodothyronine) and T4 (thyroxinne) were within normal levels. Ultrasound of the neck showed a 2.71 cm × 2.59 cm solid nodule arising from the left thyroid lobe, with small contralateral nodules measuring 0.5 and 1.1 cm (). There was no invasion to adjacent tissues.\nFine-needle aspiration (FNA) biopsy of the thyroid mass was then performed. FNA biopsy reported malignant spindle-shaped cells. Computed tomography of the chest and abdomen showed no distant metastases. Serum calcitonin, carcinoembryonic antigen, and thyroglobulin were within normal levels. Initially, the left thyroid lobe was excised and sent to pathology for frozen section examination, which reported poorly-differentiated tumor suggesting a 'malignant spindle cell tumor'. Total thyroidectomy and central neck dissection were performed. No complications occurred, and the patient was discharged on the first postoperative day.\nOn gross examination, the tumor measured 3 cm × 3 cm × 2.5 cm. Histologically, the tumor cells infiltrated the thyroid parenchyma, with no invasion to the thyroid capsule. Vascular invasion was present. Hematoxylin-eosin staining demonstrated spindle-shaped cell bundles. The tumor cells showed a disordered fascicular growth pattern, round or spindle configuration with hyperchromatic, blunt-ended nuclei and abundant eosinophilic cytoplasm (). Immunohistochemical staining with pancytokeratin, desmin, and smooth muscle actin was performed. The tumor was strongly positive for smooth muscle actin, positive for desmin, and negative for pancytokeratin (). No tumor-bearing lymph nodes were detected.\nThe oncology department did not suggest any adjuvant modalities. The patient was free of disease at three- and six-month's follow-ups. About eight months after the operation, his family doctor informed us that he had developed sudden respiratory symptoms and died in the intensive care unit with numerous pulmonary metastases.