Thymic papillary adenocarcinoma coexisting with type A thymoma: A case report

INTRODUCTION: Thymic papillary adenocarcinoma is rare. Further, thymic papillary adenocarcinoma coexisting with type A thymoma is extremely rare. Surgery remains the only effective treatment for this disease. PRESENTATION OF CASE: An 84-year-old Japanese woman presented to our institute due to abnormal chest computed tomography (CT) findings showing a 45 × 40 × 40-mm tumor located in the anterior mediastinum. A malignant tumor was suspected based on the CT findings and high serum levels of carcinoembryonic antigen. Mediastinal tumor resection was performed via video-assisted thoracic surgery through the left thoracic approach. This patient was discharged from our institute without any problems at six days post-operation. DISCUSSION: This report has three major implications. First, one of the tumors was papillary adenocarcinoma. Primary papillary adenocarcinoma of the thymus is exceedingly rare. Second, papillary adenocarcinoma and type A thymoma coexisted in this tumor. Third, epithelial thymic tumor should be resected completely, since complete resection has been reported to be associated with an improved prognosis. CONCLUSION: We encountered a rare case of thymic papillary adenocarcinoma coexisting with type A thymoma.