I recently discovered a small tender lump on left side of groin. no symptoms, just a lump thats very tender. mobile. does this sound malignant?

Probably normal: Most people have small lymph nodes in the groin. It's not abnormal. Since it's tender, you might have a minor infection in the leg on that side: hang nail, skinned knee, pimple, etc. There is almost no chance this is a malignancy. Don't worry about it -- but see a doctor if the node enlarges, if very tender, if you develop fever, etc.