I've owned Sphynx cats for 12 years and this is a new one for me. My kitten (5 months old) has a large (about 1 inch in diameter) solid lump under her skin on her upper leg. It's bumpy and abnormal in shape when I feel it. The surface of the skin is pristine ... nothing but her smooth kitten skin. She's acting completely normal, and it doesn't seem to hurt her. I noticed it today...could have been there before today, but it would have been hard to *not* notice it. any ideas? I've uploaded a photo.