Final answer:
The most likely sign or symptom of an inflamed gallbladder is pain in the right shoulder due to referred pain.
Step-by-step explanation:
One sign or symptom that you would most likely encounter in a patient with an inflamed gallbladder is pain in the right shoulder. This is known as referred pain, where pain felt in one area is actually originating from another area. In this case, the inflammation in the gallbladder can irritate the diaphragm, which shares nerve pathways with the shoulder, leading to shoulder pain.