Do you always biopsy suspicious liver lesions if you have a biopsy from the pancreatic mass showing PDAC?   

I don’t always biopsy especially if the tumor marker is very high. I start with treatment and reassess. I do think a good liver MRI with contrast can be helpful here as well. One important caveat: I do biopsy if there is scant tissue from the pancreas biopsy so I can send the NGS panel. 

I would like to add a couple of thoughts to this discussion. Firstly, recall that if a patient presents with a pancreatic mass and a scan indicating liver metastases that can reasonably be biopsied, the biopsy should be done on a liver met, not the primary. Secondly, if a patient already has a tissu...

Agree 100%. While not absolutely necessary it can be helpful. Primary tumor biopsies can often be QNS for NGS so getting a liver biopsy is reasonable. Start treatment and obtain biopsy since initial management doesn't hinge on stage. Also if you have a particularly good response to treatment it can ...