For a few months, a 47-year-old man has noted a persistent, asymptomatic patch on his upper arm. The patient has no significant medical problems, takes no medications, and has no history of seasonal allergies. He keeps a pet cat and enjoys gardening.
Answer: Basal cell carcinomaSee the full case at Consultant360
A skin biopsy, confirmed the clinical suspicion of basal cell carcinoma. Because the patient worked shirtless every summer in his garden, actinic keratosis was a diagnostic consideration. The basal cell carcinoma was excised completely, and the patient was instructed to use sunscreen when exposure to the sun could not be avoided.
This asymptomatic lesion was neither pruritic nor scaly, thus ruling out nummular eczema and pityriasis rosea, respectively. Fungal infections generally are scaly and often pruritic; although they expand slowly, they do so more quickly than basal cell carcinoma.