Gall bladder rule 4: D.D. of Gall bladder mass versus hepatocellular carcinoma

-How you can differentiate between a gall bladder mass causing invasion of the surrounding hepatic tissue from a hepatocellular carcinoma invading the gall bladder.
It is most common to see a gall bladder carcinoma invading surrounding hepatic tissue in clinical practice, on the other hand, it is very rare to see a hepatocellular carcinoma invading a normal gall bladder in clinical practice.
So when you are confronted with a mass occupying gall bladder fossa and surrounding hepatic tissue, and according to this rule, you should consider it a gall bladder mass invading the liver rather than a hepatocellular mass invading gall bladder.