Is it possible to have a breast tumor causing upper back pain deep in right shoulder for over 2 years? mamagram ok. ultrasound right breast ok? spine

Unlikely: If your mammogram and ultrasound show no tumor then this is unlikely. A shoulder xray or ct scan might help find cause, but tumor very low probability. Hope it gets better soon!

Other causes too: It is difficult to provide an answer only with the information provided. If you have chronic back pain, my advise is to make an appointment with a physician. Certain tumors can metastatize to the spine. If you have no history of cancer, there are more common explanations for your pain. A history of tumor would require additional investigations (mri, others, depending on the clinical circumstance).