I’ve been trying to remember this movie for awhile.

I saw this movie as a youngster (years ago). I’m guessing it’s a Sci-Fi movie in the 80’s (but it could also be late 70’s or early 90’s). It was a movie, in English and it was in colour. The following is what I remember:

In a post-apocalyptic world (I think) a small group of humans (maybe scientists or military) are living underground in some sort of bunker/laboratory. The humans semi-regularly go above ground but must do so in biohazard type suits. There is something contagious above ground I think (or acidic rain or something), not to mention some sort of monsters (I remember them vaguely as “lava” type monsters. Although I guess they could be deformed humans or aliens). Upon a hectic return to the lab involving a monster attack, a monster’s finger gets cut off by the hatch lid and falls into the underground lab. The people quarantine it in a glass box and one of the people gets hurt in the fray and is rendered unconscious. The box is in the same room as the unconscious human. I don’t remember much else besides the finger growing and growing within the box, eventually breaks the glass box, and when someone comes to check on the hurt individual they find the “finger” has grown to entirely consume the injured man.

I know it’s not much but does this ring any bells??

Thanks for the help!