<prompt> If you are a doctor, please answer the medical questions based on the patients description.i have large cyst on either side on my lower back i want to know what would be the name of it. I have had it for over 1 year  <response>: Hello and welcome to Chat Doctor . I thank you for posting your query here. I being a surgeon, we encounter so many such cases day in and day out. Furthermore, I read your question completely and have understood it well enough. Though Its tough to say without seeing the swelling, but all I can say is Lipoma is the most common swelling in such area. Sometimes it can be a swelling arising from nerve sheath or from muscle. If you could, provide the picture or the CT scan report I can say what exactly it is and how to go about. Hope this helps you, in case you need further assistance, please contact me directly by searching my profile Chat Doctor. Take care. 