After reading this post you will learn the following:- 
- Premalignant Meaning
- Premalignancy Vs Malignancy
- Oral Premalignant Lesion – Definition with Examples
- Premalignant Condition – Definition with Examples
- Changing Terms
INTRODUCTION
- Premalignant:-
- pre means before
- malignant means cancer
- Thus, Premalignant means a forerunner of cancer
- These precancerous lesions encompass a histological continuum between the normal mucosa at one end and high grade dysplasia/carcinoma in situ, at the other, establishing a model of neoplastic progression.
- Premalignancy is distinguished from malignancy by:-
- absence of invasiveness (invasion is the movement of cancer cells from their normal location into the surrounding non-cancerous tissue,. another word for invasion is infiltration)
- absence of metastasis
- Thus, premalignant means to have the potential to undergo malignant transformation
STILL CONFUSED!!!!!!!!! premalignant means - tissue that is not malignant now but can become malignant or involving abnormal cells which are associated with an increased risk of developing into cancer or a condition that may(or is likely to) become cancer
ORAL PREMALIGNANT LESION – DEFINITION WITH EXAMPLES
DEFINITION:-
Oral premalignant lesion defined by the World Health Organization (WHO, 1978) as “a morphologically altered tissue in which cancer is more likely to occur than in its apparently normal counterpart.”
EXAMPLES:-
Precancerous lesions (clinical classification)
• Leukoplakia
• Erythroplakia
• Palatal keratosis associated with reverse smoking
Precancerous lesions (histological classification)
• Squamous epithelial dysplasia
• Squamous cell carcinoma in situ
• Solar keratosis
ORAL PREMALIGNANT CONDITION – DEFINITION WITH EXAMPLES
DEFINITION:-
Precancerous condition defined as “a generalized state associated with a significantly increased risk of cancer”.(WHO,1978)
EXAMPLES:-
- Lichen planus
- Oral submucous fibrosis (OSMF)
- Sideropenic dysphagia
- Syphilis
- Discoid lupus erythematosus
- Xeroderma pigmentosum
- Epidermolysis bullosa
CHANGING TERMS/DEFINITIONS BY WHO
- 1978 – Premalignant Lesions & conditions (As defined above)
- 2008 – Premalignant Disorders
- The risk of malignancy being present in a lesion or condition at the time of initial diagnosis or at a future date
- Current, Potentially malignant Disorders
- as the term premalignant indicates that all premalignant/precancerous lesions will turn into cancer. But not all precancerous lesions/conditions will turn into cancer, therefore the more appropriate term is “Potentially malignant Disorders”
- it is important to identify these potentially malignant disorders through clinical, histological & molecular examination to help in early detection & treatment of cancer
REFERENCES
- Shafer’s Textbook Of Oral Pathology
- Neville – Oral & Maxillofacial Pathology
- Image – Wikipedia