A case report of thyroid sarcomatoid carcinoma

Rationale

Sarcomatoid carcinoma represents a rare subtype of highly aggressive malignant neoplasm. Sarcomatoid carcinoma of the thyroid is extremely uncommon, accounting for merely 1% to 2% of all thyroid malignancies. It is marked by rapid progression and unfavorable prognosis, with a median survival of only 5 to 6 months. Additional case data are required to assist clinicians in the diagnosis and treatment of this rare disorder. Patient concerns: A 65-year-old male presented with fever and left cervical pain. Physical examination identified a hard palpable mass within the left thyroid lobe. Diagnoses: Thyroid ultrasonography revealed a hypoechoic nodule within the left lobe, with an anterior-posterior-to-transverse diameter ratio >1; circumferential calcification and scattered intranodular blood flow signals were observed. Additionally, enlarged and fused left cervical lymph nodes were identified. Computed tomography demonstrated that a left thyroid mass was compressing the trachea. A percutaneous fine-needle aspiration biopsy combined with immunohistochemical staining (showing positivity for both cytokeratin and vimentin) ultimately confirmed the diagnosis of thyroid sarcomatoid carcinoma.