A bag growing on the buttocks without pain or itching for several years may be a lipoma, common warts, etc., generally do not need treatment, or surgical excision, etc. according to the situation.
1. Lipoma: it is a common benign tumor, if there are no symptoms or the tumor is small, there is no need for treatment, regular observation can be; if there is pain and other symptoms or the tumor is large, you can consider surgical excision.
2. common warts: can occur everywhere in the body, caused by human papillomavirus (HPV) infection, belonging to the benign superfluous organisms, mostly manifested as soybean size, or larger pimples, generally do not need treatment, can disappear naturally, 5 years clearance rate of about 90%.
It is recommended to go to the hospital for examination, early diagnosis and treatment under the guidance of the doctor.