Laparoscopic scar: a mimicker of Sister Mary Joseph's nodule on positron emission tomography/CT

Positron emission tomography/CT is an established imaging method in the diagnosis and staging of cancers. (18)F-fluoro-2-deoxy-d-glucose (FDG) is the most commonly used radiotracer in positron emission tomography/CT. It is a tumour viability agent and usually its uptake within a lesion reflects the presence of a viable tumour tissue. However, false-positive FDG uptake is known to occur in benign processes of either inflammatory or infectious aetiology. We describe FDG uptake at the site of laparoscopic scar that mimicked Sister Mary Joseph's nodule in a patient with gastric adenocarcinoma. Here, the knowledge of the patient's history and subtle imaging findings helped in accurate staging of the patient. In this case report, we emphasize the value of the knowledge of the patient history and awareness of different pitfalls of FDG to achieve a correct diagnosis on positron emission tomography/CT.