Hi and welcome to HCM. Thank you for your querry.
No, there is a minor possibility that this is cancerous. This is typical finding of fibroadenomas. Such enlarged cancers would cause much more intensive symptoms. usually ultrasound
can evaluate with high sensitivity is this malignant. If you want to be sure, biopsy
can be performed but i dont think this is necessary. Just do frequent follow ups and everything will be fine.
WIsh you good health.