Question

What is the most common type of malignant melanoma?

• A. Superficial spreading
• B. Acral lentiginous
• C. Nodular
• D. Lentigo maligna

Hint:

Recall which melanoma subtype grows outward on the surface first before invading deep, and is most frequent overall.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
We need to know which histological subtype of malignant melanoma occurs most often overall.

Step 2: Key Formula or Approach:
Recall the approximate frequency of each melanoma subtype: superficial spreading, nodular, lentigo maligna, and acral lentiginous.

Step 3: Detailed Explanation:
Superficial spreading melanoma is the most common subtype of cutaneous malignant melanoma, making up roughly two thirds to three quarters of cases in most populations. It grows outward along the skin surface (radial growth) for a period before invading deeper, which often allows earlier detection.
Nodular melanoma is the second most common type. It grows vertically from the start, with little or no radial growth phase, so it tends to present later and carries a worse prognosis stage for stage.
Lentigo maligna melanoma arises from a pre-existing lentigo maligna, usually on chronically sun-damaged skin such as the face in older patients. It is less common overall than superficial spreading melanoma.
Acral lentiginous melanoma occurs on the palms, soles, and under the nails. It is the least common subtype in fair-skinned populations, though it makes up a larger share of melanomas in dark-skinned populations.

Step 4: Final Answer:
Superficial spreading melanoma is the most common type of malignant melanoma overall.
\[ \boxed{\text{Superficial spreading melanoma}} \]