**Question:** Malignant form of intraoral acanthosis nigricans is associated with:

A. Hepatocellular carcinoma
B. Pancreatic cancer
C. Breast cancer
D. Thyroid cancer

**Core Concept:**
Acanthosis nigricans (AN) is a skin condition characterized by hyperkeratinization and thickening of the skin, typically involving flexural regions. It can be classified into three main types: benign, intermediate, and malignant. Benign AN is associated with hormonal imbalances, while intermediate AN is linked to insulin resistance. Malignant AN is a sign of internal malignancies, particularly those involving the gastrointestinal tract, endocrine system, and lungs.

**Why the Correct Answer is Right:**
The correct answer is associated with pancreatic cancer (B), as pancreatic cancer is known to cause insulin resistance, which in turn leads to the development of intermediate AN. Malignant AN, therefore, indicates the presence of pancreatic cancer.

**Why Each Wrong Option is Incorrect:**
A) Hepatocellular carcinoma (A) is a liver cancer and does not directly cause insulin resistance or intermediate AN.
C) Breast cancer (C) is a different type of cancer and does not typically lead to insulin resistance or intermediate AN.
D) Thyroid cancer (D) is a thyroid disorder and does not cause insulin resistance or intermediate AN.

**Clinical Pearl:**
Malignant AN is a useful clinical clue to identify pancreatic, endocrine, or respiratory malignancies, enabling early detection and prompt intervention for improved patient outcomes.

**Correct Answer:** B. Pancreatic cancer