Okay, let's tackle this question step by step. The question is about a patient who had a laparoscopic cholecystectomy for cholelithiasis (gallstones), and the pathology report shows adenocarcinoma that has invaded the muscular layer. The CT scan was normal. The next step in management is being asked.

First, I need to recall the staging of gallbladder cancer. Gallbladder cancer is staged based on how deep the tumor has invaded the layers of the gallbladder wall. The layers are: mucosa, submucosa, muscularis propria, serosa, and surrounding structures. Invasion into the muscular layer would be Stage II according to the TNM classification.

Now, after a laparoscopic cholecystectomy, if adenocarcinoma is found that has invaded the muscular layer, the next step is usually surgical resection. Since the CT was normal, there's no evidence of distant metastases. The standard treatment for Stage II gallbladder cancer is a radical cholecystectomy, which includes removing the gallbladder along with a margin of liver tissue (usually a wedge resection of the liver bed) and regional lymph node dissection. This is because the cancer may have spread beyond the gallbladder wall even if imaging doesn't show it yet. Laparoscopic cholecystectomy is not sufficient for cancer that has invaded beyond the mucosa; a more extensive procedure is needed.

Looking at the options provided (though they aren't listed), the correct answer would be the one that suggests a radical cholecystectomy. The other options might include things like observation, chemotherapy, or other less aggressive treatments. But based on the staging, surgery is the primary treatment.

I should also consider that sometimes, if there's residual disease after the initial surgery, further adjuvant therapy might be needed. However, the first step after finding Stage II disease would be the radical surgery. So the next step is definitely more extensive surgery.

**Core Concept**
This question tests knowledge of the management of gallbladder cancer following laparoscopic cholecystectomy. Adenocarcinoma invading the gallbladder muscularis propria (Stage II cancer) requires **radical cholecystectomy** to achieve curative resection, including hepatic resection and lymph node dissection.

**Why the Correct Answer is Right**
Adenocarcinoma invading the muscular layer (T2 tumor) necessitates **radical cholecystectomy** with resection of a 2–3 cm margin of liver parenchyma and regional lymphadenectomy. Even if imaging (CT) is normal, histopathology showing muscularis invasion implies high-grade cancer with potential microscopic spread. Laparoscopic cholecystectomy is inadequate for curative intent in such cases. The goal is to achieve clear margins and stage accurately.

**Why Each Wrong Option is Incorrect**
**Option A:** Observation is incorrect. Stage II gallbladder cancer is not a low-risk lesion; observation leads to recurrence and poor outcomes.
**Option B:** Chemotherapy alone is incorrect. Adjuvant chemotherapy is used post-surgery, not as primary treatment for resectable tumors.
**Option C:** Extended hepatectomy is unnecessary unless the tumor involves deeper layers (T3/T4) or major vessels, which is not indicated here.

**

✓ Correct Answer: B. Wedge hepatic resection with lymph node dissection