Besides breast cancer/lymphoma, what else causes a hard, immovable, non-tender lump under collarbone in area of infraclavicular node on left side? thx

Many things: Infection, cyst, benign tumor, bruise/bleed; most lumps are not cancer, but masses that are cancer in general continue to grow with time. If you are over 40, I would recommend you should be having annual mammography, regardless of whether you have an infraclavicular mass. Pay attention to this mass, and you should try to see your physician regarding this.

See your doctor: It is difficult for anyone of us to answer this question without examining you, knowing your history and viewing any x-rays/scans. I recommend you take this concern to your doctor. Keep asking questions until you get an answer that you are comfortable with. Best of luck!!

No other: Infraclavicular lesion is essentially lymph node in origin. While axillary nodes attain 3 levels of spread, only level 1 palpable, Any node noted in infrac;lavicular region is likely Rotters node, an interpectoral node that is usually breast in origin but can spread from cutaneous lesions Tumors spreading from abdomen/ pelvis usually go to Virchows node in the L. supraclavicular region.