Mastocytoma

A mastocytoma is an accumulation of mast cells, a type of immune system cell, that usually appears as a lesion or spot on the skin. It is more common in childhood and, in many cases, tends to behave in a benign way.

How it shows up: it usually appears as a yellowish or brownish plaque or nodule that may redden, swell, or itch when rubbed.

Common causes: it is related to a local proliferation of mast cells, whose exact origin is not always identified.

Who should you see? Evaluation is handled by the dermatologist or, in children, the pediatric dermatologist, with support from the general practitioner as a first point of contact. With a lesion that changes, grows, or causes persistent discomfort, the most sensible thing is to schedule a specialized evaluation.