Concerned about growth

A couple of weeks ago I asked a question about a growth on the inside of my forearm, and had sent you a follow-up to your response but never received a reply so I am submitting another question.  I have a dermatologist appointment scheduled, but in the meantime I still have concerns about this growth. It is smaller than a pencil eraser in diameter (approx 4mm), dome-shaped (maybe 1mm high), and firm.  It is pink, somewhat pearly or waxy looking, and sometimes scales slightly. It has been there for close to a year, and hasn't grown much in size (width or height) since I first noticed it. While waiting for my derm appointment, I have scoured the web for information on skin growths, and saw pictures and descriptions for both basal cell carcinoma and nodular melanoma that resemble this bump on my arm.  Of course, I am most concerned over whether or not this could be melanoma.  Information across the different websites is inconsistent and confusing, and quite alarming. My question is about timing. I've read that basal cell carcinoma is slow growing and fairly easily contained once discovered.  Since this growth has been there close to a year without much visible change, I could see how it would fit the description of BCC.  How fast does nodular melanoma grow, and would you expect to see much change in it over the course of a year?  From what I've read, it is the most aggressive form of skin cancer, and spreads rapidly. I know it may sound like I'm grasping at straws here, but I'm stressed out over it to the point of losing sleep. And with every slight pain in my body, I imagine that it's the melanoma that has spread. I know you can't diagnose over the internet, but like everyone out here, I'm looking for some sort of reassurance until I my dermatologist appointment.  Thanks for your advice.

[Alan Rockoff, MD]

Of course, I can't tell what you have without looking, but this sounds like a dermatofibroma, a benign growth of fibrous tissue cells that looks just like what you are describing.  Nodular melanomas are not only very rare, but they are usually jet black.  Also, they grow over a year's times.  I guess you won't be totally reassured till you see the skin doctor, but the chances are very, very high that you'll find you're fine, and then your anxiety-related aches will go away.

Take care.

Dr. Rockoff

[distressed1]

Dr. Rockoff, thanks for your quick reply. I am relieved by your description of nodular melanoma being black. There are various websites that say they are usually pink or red (amelanotic); others say they are usually brown or black. It is all very confusing because there is no consistent verbage that accurately describes the features and various forms. This isn't the only inconsistency I have found in the different descriptions. One site will say that they normally appear on the trunk and legs, others will say they normally appear on the face, scalp, or arms, and on and on.  What was most alarming was to read that a few studies (out of Australia or NZ, I believe) say it is one of the most missed diagnoses in dermatology -- often overlooked by GPs and dermatologists -- or confused with basal cell carcinoma. All this together is very overwhelming. At any rate, I appreciate your response in helping me put this in perspective.

[Alan Rockoff, MD]

Amelanotic melanomas are indeed hard to diagnose, but they are also extremely rare.  If your doctor has even a slight concern, he or she will do a biopsy, which is definitive.

Dr. Rockoff

[distressed1]

Well, Dr. Rockoff, you were spot on (no pun intended).  I just got the call from my dermatologist ... the growth on my arm is benign.  And as you suspected, a dermatofibroma.  Thank you for your help and reassurance during this very stressful time.

[Alan Rockoff, MD]

Great.  Thanks for the followup.

Dr. Rockoff