Certified Tumor Registrar (CTR) Practice Exam

Melanoma is most likely to develop in which layer of the skin?

1. Dermis

2. Epidermis

3. Hypodermis

4. Muscle

The correct answer is: Epidermis

Melanoma is most likely to develop in the epidermis, which is the outermost layer of the skin. This is where melanocytes, the cells responsible for producing the pigment melanin, are primarily located. Melanocytes are responsible for the color of the skin and can become malignant, leading to melanoma. The epidermis provides a thin barrier that protects the underlying layers, but it is also where skin cancers most often originate, particularly those related to sun exposure. Since melanoma arises from these melanocytes, it is logical that its development would be concentrated in the epidermis. In contrast, while the dermis supports and nourishes the epidermis, it is not the tissue where melanoma primarily initiates. The hypodermis, which consists mainly of fat and connective tissue, serves as insulation and a cushion, and has no direct involvement in the development of melanoma. Similarly, muscle tissue is not associated with skin cancer formation, as it is not part of the skin structure where melanocytes reside. Therefore, the epidermis is the correct layer for the development of melanoma.