SKin cancer?

My husband is 44 y/o - is a landscaper and has worked outside for 25 years.  He has a mole on his chest that is raised and over the past several months I have noticed that there is a 1/8 -1/4 inch white patch around it.  Does that sound like something we should have checked out?  Or could it just be a gradual pigment change?

[Dr_Aparna]

Hi,
Moles are a clump of cells with different pigment (colour) than the surrounding skin.The number and type of moles that a person has is largely determined by family history.
Melanoma is cancer of the pigment cells. Only approximately 30% of melanomas arise from moles.
Compared to an ordinary mole, these are usually larger, have an irregular border and perhaps an uneven colour. Some dysplastic moles have a 'fried egg' appearance with a dark centre and a large tan halo (up to 2 cm). 5 to 20% of white adults have at least one dysplastic mole. These types of moles possibly convert to melanoma more frequently than a normal mole. The presence of several dysplastic moles indicates an increased risk of melanoma developing somewhere on the individual's skin.
Your moles should be checked by your Doctor twice a year (or more regularly) for any change in size or appearance of your moles, inflammation of the surrounding skin or bleeding.
Moles can be removed by a variety of simple techniques including surgery.
ref:http://au.health.yahoo.com/041101/25/1v1n.html
You need to contact your Doctor immediatelysince you have noticed achange in the appearance of the mole and its surrounding skin.