Bb sized lump outside of anus hemorrhoid?

Likely: A hemorrhoid can be thrombosed (filled with blood) and thus harden and present as a firm lump outside of the anus. These usually resolve on their own. If you do not have improvement after a week, i would see your doctor.

Not necessarily: Some other problems can cause a lump in the anus. Most of the time benign reasons like hemorrhoids, fistulas, abscesses, cysts. There are also so e other conditions like rectal or anal cancer than can produce this. You better have it checked by your doctor.