Question for medical dopers (Warning unsettling pictures).

WARNING! UNSETTLING PICTURES OF ODD SKIN GROWTHS AT THE LINK

I’m not kidding here.

Last warning.

http://blog.wfmu.org/freeform/2007/03/missionary_enco.html

Now the question:

Several people have suggested that the gentleman in question is suffering from a form of the Shope papillomavirus which affects rabbits.

Now if it IS a papillomavirus, why would it be limited to his hands/feet? I thought they would infect on contact with other parts of the skin.

If it’s not a virus, say it’s a tumor, again, why would it be limited to the specific areas in question?

I guess I’m just wondering how growths remain within specific body areas rather than just spread.