Age Spots/Liver Spots/Sun Spots

Ok, I'm 18 - I recently visited my doctor because I have several brown spots in different sizes on the side of my stomach below my breast! I am a male and I am very rarely in the sun very long. When I am in the sun I always have a shirt on most of the time an undershirt as well (unless I'm swimming which might be 5 times a year, then there is no shirt). I was told that they were "Age Spots" but my question is: If they are caused by sun damage and that area is never exposed to the sun how did I get them? And they came on VERY suddenly like I noticed 3 spots and they couldn't have been there long and then bam 2-3 more showed up and some even grew. They do feel different then the surrounding skin. Should I be worried and have the doctor take a second look? They are all concentrated in the same area, I don't have them on anyother areas on my body. Could they also be relative to weight by anychance?

Thanks,
Justin T.

[Dr_Aparna]

Hi,
Sun spots, or solar lentigines, are hyper pigmented, single or multiple brown spots located on areas of the skin that have been exposed to the sun.

Often referred to as liver spots or age spots, solar lentigines may appear after treatment with ultraviolet light (PUVA) or after using tanning booths. Often referred to as liver spots or age spots, solar lentigines may appear after treatment with ultraviolet light (PUVA) or after using tanning booths.
People with light skin are particularly susceptible. They may appear at any age, usually on the hands and face. Even if you are well covered, do you spend a lot of time outdoors?
If so, then there is a possibility that they should be sun spots.

They could also be moles, but since that have been examined and ruled as sun spots, then you could go along with this diagnosis.
Just watch out for any changes of crusting/ bleeding or ulceration and have it attended to immediately.

If you are still not sure, you can always go in for a second opinion. You can request to have a biopsy done to rule out anything serious. They usually do not have any association with weight issues.
ref:http://www.skinresourcecenter.com/CommonConditions/SunSpots.aspx