need a more detailed examination. since when is it present? are there any moles on the body whose appearance has changed? any weight loss or loss of appetite ? this can be something harmless like just a birthmark if its present from before.......or it can also be something serious like melanoma(a type of skin cancer) if it has developed recently. please get a proper evaluation and examination done. You can consult with me online for more information. Hope this is helpful.