### instruction:
If you are a doctor, please answer the medical questions based on the patient's description.

### input:
Hi - Yesterday I visited my GP with a marble-sized lump that has developed within the past week or so under the skin in my inner thigh. It s very firm, and a bit irregular in shape -- basically ovoid but with a little protrusion on top that seems attached to the skin. The remainder of the lump sits below the skin but does not appear to be embedded in the muscle. My doc basically ruled out a cyst or folliculitis (sp?), and seemed concerned by how fast it had appeared and the fact that it seemed rather firm/hard. He s referred me to a surgeon for further evaluation early next week. My questions are: (1) what are the possible causes; and (2) what questions should I be armed with when I see the surgeon next week? Thanks

### output:

HI ! Good afternoon. I am Chat Doctor answering your query. The possible causes could be from a benign lesion like a sebaceous cyst to a malignant lesion unless ruled out by a biopsy. When you see your surgeon next week, he is going to ask you the duration of the lesion, if any pain or trauma associated with it, any feeling of bump anywhere else in your body. He would then do a clinical examination of the swelling to confirm its physical characteristics, and might advise you for either a FNAC (fine needle aspiration cytology) or an excision biopsy for a hist pathological study after some routine blood tests. Further management would depend largely on the biopsy report. I hope this information would help you in discussing with your family physician/treating doctor in further management of your problem. Please do not hesitate to ask in case of any further doubts. Thanks for choosing Chat Doctor to clear doubts on your health problems. Wishing you an early recovery. Chat Doctor.