**Question:** Premalignant lesion of oral cavity includes - a) Erythroplakia b) Fordyce's spot c) Leukoplakia d) Keratoacanthoma e) Aphthous ulcer

**Core Concept:** Premalignant lesions are conditions in which the cells have the potential to undergo malignant change and develop into cancer. In the oral cavity, these lesions are important to identify and monitor as early intervention can prevent the progression to oral cancer.

**Why the Correct Answer is Right:**
Correct Answer: c) Leukoplakia

Leukoplakia refers to a white patch in the oral cavity that cannot be easily wiped off and lacks a known cause. It is a premalignant lesion, which means it has the potential to undergo malignant change and develop into oral squamous cell carcinoma. Leukoplakia is characterized by abnormal cell growth and is often associated with irritation or habitual factors like tobacco use.

**Why Each Wrong Option is Incorrect:**

A. Erythroplakia (reddish patch) and Keratoacanthoma (rapidly growing tumor) are not premalignant lesions of the oral cavity. Erythroplakia is characterized by red patch and may be associated with Human Papillomavirus (HPV) infection. Keratoacanthoma is a benign tumor that grows rapidly and has a low potential for malignant change.

B. Fordyce's spot (grayish white spots caused by sebaceous glands) is a benign condition and is not considered a premalignant lesion of the oral cavity.

D. Aphthous ulcer (inflammatory lesion due to immune response) is a self-limiting condition and does not carry the potential for malignant change. While it may recur, it is not considered a premalignant lesion.

**Clinical Pearl:** Premalignant lesions of the oral cavity are crucial to detect and manage to prevent oral cancer development. A thorough oral examination should be performed in patients with risk factors like tobacco use, human papillomavirus (HPV) infection, and history of oral lesions. Regular follow-up is necessary for premalignant lesions like leukoplakia to monitor their progression and initiate appropriate management.