If people don't show visible signs of a wart or carcinoma, then their biopsy probably wasn't tested for HPV. If they did show a wart, then your options are verruca vulgaris, squamous papilloma, and condyloma acuminatum. (HPV 2, 4, 6, and 11)
A worthwhile read, if you have the stomach for the pics (I've seen worse, much worse).
I can't figure out which strains of HPV you would even test a biopsy for, i.e. which strains stay below the epidermis but aren't detected in the stratum corneum, which you could do a smear to find. Oh, and HPV 16 predominantly presents itself on the tongue and back of the throat.