On abdominal ultrasound gall bladder shows at neck and comet tail aifacts. The most likely diagnosis will be:

Adenomyomatosis Repeat from May 11 Adenomyomatosis is a benign condition characterized by hyperplastic changes of unknown etiology involving the gallbladder wall. It causes overgrowth of the mucosa, thickening of the muscular wall, and formation of intramural diveicula or sinus tracts termed as Reokitansky-Aschoff sinuses. These sinuses may contain cholesterol crystals. The presence of cholesterol crystals in theses sinuses can result in "ring down", "V-shaped",or "comet-tail" aifacts. The disease can be focal or diffuse. It has no malignant potential.