### Patient: Doctor, I have a weird lump on my back, and it's causing me a lot of pain in my anus. I also noticed that the skin around it looks irregular, and there seems to be a fluid retention. What could it be?
### Doctor: Based on your symptoms, it seems like you have a pilonidal cyst. It's a condition where a cyst or abscess forms in the crease between the buttocks near the tailbone. The skin growth and irregular appearance are due to the inflammation caused by the cyst.