Hi, thanks for writing to HCM and sharing your health concerns!
Well, If I were your treating Doctor for this case of knot on back of the thigh, I would come up with three possibilities, these include:
1. benign inflammatory lesions like chronic abscess,
folliculitis, antibioma, fibroma, inflamed mole!
2. The second possibility is of benign and simple conditions like lipoma or
neurofibroma,
histiocytoma or dermatofibroma; there is nothing to worry about these!
3. The last possibility is of sebaceous cyst or some other cysts like bursa,
ganglion cyst or parasitic cyst! Nothing to worry about these also!
I suggest you to go for an FNAC /biopsy and if necessary
ultrasound of the lump for confirmation and to relieve your concerns!
Hope this answers your question. If you have additional questions or follow up questions then please do not hesitate in writing to us. I will be happy to answer your questions.
Wishing you good health.