So some cancers are sort of "infectious"- Ugh!

[astro]

Per this review of “House”

Henry is well outside the normal age range for testicular cancer (it’s primarily a disease of younger men), so that wouldn’t be as high on my list of possible diagnoses. If it were on my list, I certainly wouldn’t do a needle biopsy. There are certain cancers where needle biopsies are not performed for fear that the cancer will track — spread up the needle’s path. Testicular cancer is one of these cancers. If it is suspected and confirmed by scrotal ultrasound, then the testes is removed. No biopsy except in rare cases, and then a special surgical biopsy is performed. Never a needle biopsy.

[Ice_Wolf]

Certainly seems to be the case.

Our data suggest that subclinical seeding is a more prevalent process than was formerly believed. In particular, tumor seeding within the needle track can occur following transrectal biopsy, a phenomenon that has never been previously recognized.