Metastatic Lung Adenocarcinoma Presenting Within Struma Ovarii: A Rare Case of Tumor-to-Tumor Metastasis

Abstract

Tumor-to-tumor metastasis is extremely rare. We herein describe a 67-year-old woman who underwent FDG PET/CT for initial staging of lung cancer. This imaging examination revealed a pelvic mass with peripheral FDG uptake, suggesting a metastatic tumor from lung cancer or a secondary malignancy. Examination of a surgical specimen confirmed metastatic lung adenocarcinoma within a struma ovarii, suggesting tumor-to-tumor metastasis.