If a hard mass is found in the right side of the buttock, it can be caused by the following diseases: First, it is a localized neurofibroma, which is also very common, and many patients have multiple occurrences, mainly along the direction of nerve travel. There are also many patients who have lumbar disc herniation and whose symptoms do not improve significantly even after choosing physiotherapy, need to combine ultrasound examination, choose lesion removal surgery and conduct pathological examination. Secondly, there are also some patients who have subcutaneous lipomas, and if they gradually increase in size, they need to choose surgery to remove them.