I have had several mini-lop rabbits over the years and know a bit about them. Rabbits live to be about 8 years old, and I don't know how old your rabbit is, but a lump on the neck and lack of appetite sounds serious. If it was just a 'fatty tumor' or cyst, your bunny's appetite would not be effected. Only a vet can tell you exactly what it is, but make sure your rabbit is drinking water. They dehydrate very quickly! Try tempting him/her with parsley (they love it) celantro, carrot shavings or lettuce. Good luck!
