Carcinoma of the gallbladder would most likely present as:

Carcinoma of the gallbladder typically presents as diffuse thickening of the gallbladder wall, often associated with the presence of gallstones. This thickening is due to the infiltration of the tumor into the gallbladder wall, leading to an irregular contour and alteration of the gallbladder's normal structure. The coexistence of gallstones can complicate the ultrasound findings, as they may obscure the tumor but are frequently observed in patients with gallbladder carcinoma.

Identifying diffused wall thickening, especially if it exceeds 4 mm, can raise suspicion for malignancy. The presence of a dilated gallbladder with an irregularly thickened wall on imaging is a key indicator of gallbladder cancer.

The other potential presentations, while relevant to gallbladder pathology, do not align as closely with the classical presentation of gallbladder carcinoma as diffuse thickening along with the presence of gallstones.