Large hyperpigmented skin lesions are a common presentation in primary care settings. Differential diagnosis includes several benign and malignant lesions, including seborrheic keratosis and malignant melanoma; thus, excisional biopsy should be performed if there is any uncertainty. We present a man in his 60s with a painless, slow-growing dark brown plaque on his upper back. Due to the size and irregularity of the lesion, as well as the patient’s dermatological preference, an excisional biopsy was performed, which confirmed the diagnosis of seborrheic keratosis.
Mass et al. (Sun,) studied this question.