What is this on my arm??

I have this black spot on my right arm for about a year now.. see picture.  It's not going away and i am wondering what it was?  It feels like there is something inside, like a small ball.   I am starting to get nervous because it's not going away....plus when people see it, they always ask me what it is??  I tried to scratch it away but it healed and came back looking the same. Thank you in advance for your response.  

[Bhupinder Kaur, MD]

Hello,
I cannot confirm anything without examination but it can be dermatofibroma or hyperpigmented nevus. Both are benign skin growths and there is minimal chances of them being turning malignant.

I sincerely suggest you to consult a dermatologist and get the diagnosis confirmed. A biopsy skin may be needed to confirm the diagnosis.

I hope it helps. Take care and regards.