My husband has a large baseball sized lump on his right inner upper thigh that appeared 7 years ago no negative symptoms what can it be?

Do not ignore: Baseball sized lump is not normal. Could be slow growing benign or less likely malignant tumor. A lot of definition of mass depends on firmness, movability, discoloration, tenderness etc. Certainly a doctor should be consulted for examination and possible testing by imaging and biopsy.

Hernia: Sounds like a hernia, but i would see a doctor to be sure.