Non-invasive thymoma with widespread blood-borne metastasis.

A 49 year-old woman with multiple coin lesions in both lungs died three months after admission to hospital for progressive neurologic manifestations due to increasing intracranial pressure. At autopsy, neoplastic lesions were found in the anterior mediastinum, lungs, spleen, cerebrum, liver, right kidney and right ovary. Microscopically, the tumor was composed predominantly of epithelial cells which were arranged in an hemangiopericytoma-like pattern. Rosette formation was also prominent. This case was diagnosed as a thymoma with widespread blood-borne metastasis. Previous reports of metastasizing thymomas are very uncommon.