Metastatic cardiac tumor in the right atrium from intraductal papillary mucinous neoplasm of the pancreas

Intraductal papillary mucinous neoplasms of the pancreas (IPMNs) are relatively common neoplasms, and some of IPMNs are known to progress to invasive or non-invasive adenocarcinomas. However, metastases to other organs, especially to the heart were extremely rare. This report describes a case of IPMN with a cardiac metastasis. A 83-year-old man with branch-duct type IPMN was found a tumor in the right atrium adhering to the free wall by transthoracic echocardiography and contrast-enhanced CT scan. The CT images of the pancreas showed no remarkable changes as compared with the previous CT images. Integrated positron emission tomography/computed tomography with 2-18F-fluoro-2-deoxy-D-glucose (FDG-PET/CT) showed a significant FDG tracer uptake in the tumor of the heart, but not in the IPMN lesion. At autopsy, the tumor in the right atrium showed a white multicystic lesion similar to that observed in the pancreas, and it histologically showed the irregular gland structures with cytological atypia compatible with adenocarcinoma. Tumor in the heart showed a strong immunoreactivity for the mucin proteins MUC-1 and MUC-5AC, but focal weak staining for MUC-2. These immunohistochemical findings were similar to those in the pancreas. We concluded that a branch-duct type IPMN transformed into the invasive adenocarcinoma and metastasized to the heart. This is the first report of IPMN with cardiac metastasis to previously undescribed metastatic sites.