肺転移を伴うtype A胸腺腫の1例

A case of type A thymoma with pulmonary metastasis

type A胸腺腫は胸腺腫のサブタイプの中で最も予後が良く悪性度が低いとされ，遠隔転移をきたすことはまれである。今回我々は，前縦隔腫瘍切除時に同時に切除した肺結節がtype A胸腺腫および肺転移と診断されたまれな症例を経験したので，文献的考察を加えて報告する。

We describe a rare case of type A thymoma with pulmonary metastasis in a woman in her 60s. Chest CT showed a well-defined nodule in the right upper lobe and an anterior mediastinal mass, both exhibiting low FDG uptake. Histological examination confirmed type A thymoma in the mediastinal lesion, while the lung lesion showed similar histological features and was diagnosed as pulmonary metastasis of thymoma. Pulmonary metastasis from type A thymoma may present with imaging findings resembling benign nodules. When such nodules are detected in the lung, the possibility of pulmonary metastasis should be considered even in type A thymoma.