<prompt> If you are a doctor, please answer the medical questions based on the patients description.My friend has a lump in her thigh on the backside. It is not on the surface. It is at least the size of a walnut. She discovered this when she lost a significant amount of weight and was able to feel it more easily. She says it does not hurt. Any ideas?  <response>: Hi.noted history of non-painful lump on the patients posterior thigh. It may be a case of lipoma fatty deposit, fibrous fibrous tissue formation or a cystic formation. Other lesion types such as malignancy must also be ruled-out. It is best if you bring your friend to a doctor, preferably a general surgeon, especially if the lesion is bothering her. Diagnostics and management medical andor surgical will be directed accordingly. Definitive management is surgical excision of the lesion with proper antibiotic regimen and daily wound care thereafter. Hope this helps. Good day!! Chat Doctor. 