Hi thanks for your question.
The swelling on your thigh has following possibilities.
NO1.Lipoma ,it a benign fatty tissue tumor.
No 2.Rabdomyoma ,it is a benign tumor of skeltal muscle.
No 3.Rabdomyosarcoma,it is malignant tumor of skeltal.
I would suggest you to consult an orthopediac surgeon,who may be able to examine you to determine, what exactly this swelling is.He may advice you few investigation like FNAC (fine needle aspiration cytology.
Hope this answers your .question.

Dear patient when we try to make the differential diagnosis of a swelling or lump any where in the body ,two things are mainly considered
1 Origin of the swelling i.e from whic tissue or organ the swelling arises, it could be skin, subcutaneous fascia, adipose tissue (fat), mucle, nerve, blood vessel, lymphnode, bone, internal organs or any oyher tissue or organ relevant to the site
2. cause of the swelling i.e what is the process that has given rise to the swelling in that particular tissue or organ, it could be infection and inflammation, trauma, neoplastic process, degenerative process, any vascular phenomenon, abnormal migration through a weak area, developmental anomoly or any congenital proces. Accordingly a long list of diagnosises comes in to the mind of a doctor of which he tries to rule out some and consider others by taking a proper clinical history, and doing compleate physical examination of the patient and then tries to confirm one particular diagnosis by doing appropriate investigations. In your case the swelling could be a large inguinal lymphnode, lypoma, inguinal/femoral hernia, ectopic or undescented inguinal testes, or any bony swelling from the upper end of thigh bone or hip bone . As you say that the swelling is hard and painless, such swellings are generally of more concern ,so what i suggest you is that you better have have a direct consultation with a doctor especially a surgeon who can do a proper clinical examination of the swelling ,take a relevant history from you and will then advise you required investigations, which may include, haemogram with general blood picture, X-RAY THIGH and pelvis, Ultrasound of the abdomen pelvis and swelling, FNAC,and Biopsy or any other relevant test