Swelling under my right arm pit?

Possible lymphnode: We need details like how long it is there, painful or not, skincovering is free or attached to the underlying lump, any blackhead like area -likely a skin cyst - sebacious cyst, to r/o cancer sitting in lymphnodes- irrespective female/male breast cancers(commonest) and distant cancers like lung, thyroid, blood related cancers like lymphoma, leukemia, acute infections like breast abscess, chronic inf.