A nurse is assessing a client who reports a nevus that has increased in size and an irregularly shaped lesion that varies in color. These findings are consistent with which of the following medical diagnoses?

Rationale: A. Kaposi's sarcoma: Kaposi’s sarcoma typically presents as purplish, red, or brown macules, plaques, or nodules, often associated with immunocompromised states. It does not commonly present as a changing pigmented nevus with irregular shape or color variation. B. Malignant melanoma: Malignant melanoma often arises from a pre-existing nevus or new pigmented lesion that shows asymmetry, irregular borders, color variation, and enlargement. These characteristics align with the client’s report of a growing, irregularly shaped, multicolored lesion. C. Squamous cell carcinoma: Squamous cell carcinoma usually appears as a firm, red nodule or scaly lesion, sometimes ulcerated. It does not typically originate from a pigmented nevus and lacks the color variation described in this scenario. D. Basal cell carcinoma: Basal cell carcinoma generally presents as pearly, translucent nodules or ulcers, often on sun-exposed areas. Changes in nevi with irregular shape and color are not characteristic of basal cell carcinoma.