Question:

A 50-year old lady noticed a pigmented lesion on her breast for a few months. It is asymptomatic. What is the most likely diagnosis?

Answer: C. Seborrhoeic keratosis

Seborrhoeic keratosis is a benign epidermal skin tumour which occurs more often in elderlies. It is usually asymptomatic and can affect any part of the body but more on the face and upper trunk. The characteristic appearance is a verrucous plaque with a "stuck on" appearance on the skin. The pigmentation can vary from yellow to black. In the initial presentation, they can be flat which make them difficult to be differentiated from lentigo. They can become irritated and inflamed leading to bleeding or oozing which may alarm the patient. They tend to increase in number over the years. They are benign and can be left alone.

Malignant melanoma is a malignant tumour of the epidermal melanocytes. It is characterised by irregularity in shape and pigmentation. Bleeding and ulceration frequently occur. Viral wart is a skin infection by the human papillomavirus (HPV). It is characterised by a warty papule on any skin surface. Melanocytic naevus is a benign mole characterised by a pigmented lesion of regular and symmetrical appearance and uniformity in pigmentation.