Question

Given below are two statements: Statement I : Melanoma is a cancer of melanocytes and can, therefore, arise only in skin. Statement II : Breslow thickness of a melanoma is the most important prognostic indicator in the absence of lymph node metastases. In the light of the above statements, choose the correct answer from the options given below:

• A. \( \text{Both Statement I and Statement II are true} \)
• B. \( \text{Both Statement I and Statement II are false} \)
• C. \( \text{Statement I is true but Statement II is false} \)
• D. \( \text{Statement I is false but Statement II is true} \)

Hint:

\textbf{Key Concept: Melanocyte Distribution.} Remember that melanocytes are not exclusive to the skin. Their presence in other tissues explains the possibility of non-cutaneous melanomas. Breslow thickness is a critical parameter in staging and predicting the outcome of localized melanoma.

Answer 1

The Correct Option is D

Statement I is false: Melanocytes are pigment-producing cells found predominantly in the skin, but they are also present in other parts of the body, such as the eyes, mucous membranes (e.g., lining of the nasal cavity, oral cavity, anus, vagina), and leptomeninges. Melanoma, therefore, can arise in these extra-cutaneous sites as well, although it is less common than cutaneous melanoma. Statement II is true: Breslow thickness, which measures the vertical depth of the melanoma tumor from the granular layer of the epidermis to the deepest point of tumor invasion, is the most important prognostic factor for localized cutaneous melanoma (in the absence of lymph node metastases). Thicker melanomas have a higher risk of metastasis and poorer prognosis compared to thinner melanomas.