Primary papillary carcinoma of the thymus with invasion into subcutaneous tissue through the sternum.

Thymic carcinoma is a rare malignant neoplasm. We present a Japanese case of papillary carcinoma of thymus in a 64-year-old man that invaded into subcutaneous tissue penetrating the sternum. We describe the clinical and pathologic features of this extremely rare thymic epithelial tumor, with disease-free survival at three years of follow-up.