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It looks like the outer incision is not yet healed. There is some amount of inflammation probably due to an underlying infection. This can be taken care of using appropriate antibiotic. Discuss with your surgeon. Topical as well as oral antibiotics
may be prescribed.
Complete healing post surgically usually takes upto 2-4 weeks. Pain that you have may be related to post op pain, residual cyst
or infection too. A careful examination and repeat ultrasound
examination will help us narrow down the cause.
If the pain is severe, I encourage you to review with your doctor. Take a second opinion
if needed to rule out the aforementioned cause.
Hope this answers your query.
Wish you good and speedy recovery.