Round Papule

I had a round pink/skin color papule come up on my arm over the course of a few weeks to month.  I certain I would have noticed this bump as I put on suncreen and or showered within a few weeks if it had been the size it was a few weeks ago when I found it.  It's firm to touch and doesn't seem to be tender when compressed.  The closest thing I could find on the internet was a dermatofibroma but my lesion doesn't dimple in when sqeezed.  When I found it it was approx. 3.5 to 4mm. Over the course of 12 to 14 days it has gone down to about 2.5 to 3mm.  It's still firm to touch and no tenderness but I'm becoming concerned this could be some kind of cancer since it's not going away as fast as I would like.  

I can put a piece of glass of the top of it and press down and the color goes away?  Does that have any meaning?

Could it be a dermatofibroma even though it won't dimple in when sqeezed?

At what point should I think about having it biopsied?

Does this seem like something of concern?

[Alan Rockoff, MD]

Dermatofibromas don't usually grow that rapidly, although it may have been there longer and you didn't notice.  It may be a cyst or a piece of fibrous tissue.  Blanching on pressure just means there are blood vessels in the skin.

My advice is to leave it alone--no poking or prodding--and let a doctor take a look in 4 weeks if it's still there.  Your description does not sound sinister to me, but I guess there's no way to tell without looking.

Take care.

Dr. Rockoff

[jgaer]

I have been wearing a lot of waterproof suncreen and I was wondering if this could be a blocked pore.  Can they get to 4mm in size with no discomfort?

[Alan Rockoff, MD]

No.

Dr. Rockoff