Basically breast can arise from four quadrant of breast, but most commonly it arises from right upper outer quadrant.
Lump in this quadrant is felt as axillary mass sometimes.
Next Steps
Two investigations:
1.Bilateral breast sonomammography
2.If lump is suspicious then biopsy.
Once biopsy proven then consult cancer specialist.
Health Tips
Bilateral breast sonomammography once in a year after 40 years is recommended for all female.