Head to mid thigh MIP and PET/CT (standard protocol ) showing primary pancreas tumor and metastases in liver and midisternum lymph nodes.

Axial PET/CT images revealing unknown primary (identified as pancreas cancer), metastases in the liver and abdomen lymphnodes

A Cancer Case of Unknown Primary

Background:

Cancer of unknown primary site (CUP) represents metastatic tumor, with unidentified primary tumor location. CUPs are thought to account for 2–5% of all diagnosed malignancies. Proper treatment cannot be determined unless the primary cancer is identified. Therefore, advanced diagnostic tools are vital for primary tumor identification using nuclear imaging techniques.

Clinical history: 50-years male with unknown primary tumor diagnosed in February 16, 2021. Rectal polyp biopsy showed inflammatory lesion. CT showed liver and pleural effusions.

Our Findings: This is an abnormal FDG avid PET/CT scan.

FDG avid lesion in the pancreas appears to be primary lesion

Multiple FDG avid metastatic lymph nodes in the abdomen, mediastinum and left subclavicular region, multiple FDG avid deposits in the liver and lungs also noted.