Daughter just born 15 days, I found inside her right sternocleidomastoid muscle

Patient's question:

Doctor, hello. My daughter is only 15 days old, and I noticed a lump in her right sternocleidomastoid muscle. It doesn't hurt when pressed, but it's hard and smooth. Could it be congenital muscular torticollis? Also, what methods can we use to treat it now? Thank you for your concern, worried mother
Day
Current condition: There is a lump in the right sternocleidomastoid muscle, which doesn't hurt when pressed and is hard and smooth
First follow-up question: We visited two hospitals for surgery, but no ultrasound was performed. The surgeon said it was torticollis. Is there any other possibility? Do I still need to have an ultrasound?

Doctor's answer:

??????Hello, based on your description, it is likely caused by developmental abnormalities. It is recommended to take the child to the hospital for a check-up to determine the exact cause of the changes. Then, a corresponding treatment plan should be formulated based on the examination results. Especially regarding issues related to the child, the earlier the treatment, the better the outcome.