Thyroid carcinoma with extensive tumor thrombus in the atrium.

To our knowledge, only a few cases of thyroid carcinoma with an extensive tumor thrombus in the atrium have been reported in literature. We describe a unique case of papillary carcinoma of the thyroid with extensive tumor thrombus in the atrium. A 74-year-old man consulted our hospital because of thyroid carcinoma with an extensive tumor thrombus in the atrium. Computed tomography (CT) revealed a 2-cm tumor with extensive continuous tumor thrombus in the left jugular vein, innominate vein, superior vena cava, and atrium. The tumor was resected to reduce the risk of sudden death from tumor embolism into the pulmonary arteries. Histologically, the diagnosis was papillary carcinoma of the thyroid. Thyroid carcinoma, especially papillary carcinoma, rarely develops a macroscopic tumor thrombus. Patients with an extensive tumor thrombus generally have poor prognoses and high mortality. This patient has been followed for 7 months after successful operation without recurrence.