**Core Concept**
Hepatocellular carcinoma (HCC) is a primary malignancy of the liver, often arising in the setting of chronic liver disease or cirrhosis. The clinical presentation of HCC can vary, but it is typically characterized by symptoms such as abdominal pain, jaundice, and weight loss.

**Why the Correct Answer is Right**
The least common presentation of HCC is a palpable abdominal mass, which is often discovered incidentally on imaging studies. This is because HCC typically arises in the background of cirrhosis, which can lead to liver atrophy and fibrosis, making the tumor less likely to be palpable. Additionally, HCC often presents with non-specific symptoms such as fatigue, weakness, and loss of appetite, which can make it challenging to diagnose.

**Why Each Wrong Option is Incorrect**
* **Option A:** **Weight loss** is a common presentation of HCC, often due to malnutrition and decreased appetite. While it is not the most common symptom, it is still a frequent complaint.
* **Option B:** **Jaundice** is a relatively common presentation of HCC, especially in advanced cases. It occurs due to bile duct obstruction or liver dysfunction.
* **Option C:** **Abdominal pain** is also a common symptom of HCC, often due to liver capsule distension or tumor invasion into adjacent structures.

**Clinical Pearl / High-Yield Fact**
It is essential to remember that HCC often presents with non-specific symptoms, making a high index of suspicion and regular screening with imaging studies crucial for early detection.

**Correct Answer:** C. Abdominal pain