Question 7#
A 77-year-old man presents with a rough bump on his left ear. It is sometimes pruritic, but otherwise is not bothersome. He endorses significant sun exposure in his youth and admits to rarely using sunscreen when he is outdoors. On physical examination, the following is seen below.
For which of the following conditions is this skin condition a precursor?
A. MelanomaB. Basal cell carcinoma
C. Squamous cell carcinoma
D. Cutaneous T-cell lymphoma
Correct Answer is C
Comment:
Squamous cell carcinoma. The patient in this question is presenting with an actinic keratosis, a small and rough papule (erythematous, brownish, or skin-colored) whose risk of carcinoma depends on the degree of epithelial dysplasia. Actinic keratoses are precursors for squamous cell carcinoma, a locally invasive skin cancer that rarely metastasizes. Risk increases with excessive sun exposure and arsenic exposure. (A) Although melanoma is not associated with actinic keratoses, melanoma is also associated with sunlight exposure. Dysplastic nevi are precursors to melanoma. (B) Basal cell carcinomas are not formed from actinic keratoses. Similar to squamous cell carcinoma, basal cell carcinoma is locally invasive and rarely metastasizes. (D) Cutaneous T-cell lymphoma is not associated with actinic keratoses.