**Question:** Most common gallbladder malignancy

A. Cholangiocarcinoma
B. Hepatocellular carcinoma
C. Gallbladder adenocarcinoma
D. Choledochal cyst

**Core Concept:** Gallbladder malignancies are rare but potentially life-threatening conditions. Gallbladder cancer can arise from different cell types, including cholangiocytes, hepatocytes, and neoplastic bile duct cells, leading to various subtypes.

**Why the Correct Answer is Right:** C. Gallbladder adenocarcinoma is the most common type of gallbladder malignancy. It develops from the epithelial cells lining the gallbladder wall and represents approximately 90% of all gallbladder cancers.

**Why Each Wrong Option is Incorrect:**

A. Cholangiocarcinoma (e.g., intrahepatic or extrahepatic cholangiocarcinoma) is a malignancy originating from bile duct cells, not the gallbladder.
B. Hepatocellular carcinoma originates from hepatocytes and is less likely than gallbladder adenocarcinoma.
D. Choledochal cyst is a congenital abnormality characterized by dilated bile ducts, not a malignancy.

**Clinical Pearl:** Atypical presentations of gallbladder cancer, including abdominal pain, jaundice, or weight loss, might lead to a delay in diagnosis. Imaging and endoscopic examinations play a crucial role in detecting early-stage gallbladder cancers and improving patient outcomes.

**Correct Answer:** C. Gallbladder adenocarcinoma