What percentage of pigmented naevus can potentially undergo malignant transformation?

• A. Always
• B. Never
• C. 10 to 15%
• D. 50 to 60%

Answer: (C)

The correct answer highlights that 10 to 15% of pigmented naevus can potentially undergo malignant transformation, known as melanoma. Pigmented naevus, or moles, are the result of clusters of melanocytes which can at times become atypical and lead to skin cancer. Regular monitoring of these lesions is essential, as certain characteristics such as changes in size, color, or shape can signal the potential for malignancy.

The statistic of 10 to 15% reflects observations in dermatological studies regarding the potential risk of malignant changes, emphasizing the importance of vigilance in the management of pigmented skin lesions. While not all moles are at risk for turning cancerous, health practitioners note that a small but significant subset does present this risk, hence necessitating regular dermatological evaluations.

The other options suggest extreme positions regarding the risk of transformation, which do not reflect clinical observations. Some imply a certainty of transformation (always or never) or suggest an exaggerated risk (50 to 60%), which is inconsistent with the medical evidence observed in this area of dermatology.