Unusual Gastric Metastasis from Invasive Ductal Carcinoma Breast Mimicking as Metachronous Primary on 18F-FDG PET/CT.

The most common metastatic sites from carcinoma breast include the bones, lungs, liver, and brain. Breast cancer metastasizing to the gastrointestinal tract is very rare. This case report is about a compliant woman who was a known treated case of right breast cancer, in whom ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography showed a focal FDG avid mural thickening in the body of stomach 4 years later, for which suspicion of a second primary of gastric origin was raised, considering the rarity of being metastatic. However, histopathology confirmed it as metastasis of breast origin. This case highlights the importance of considering gastric metastasis as a differential diagnosis in patients who present with a gastric lesion and a history of breast cancer.