Is it possible for a breastcancer lump being only palpable in sitting position and not in supine position? small a-cup breast. sitting up lumpy area in bottom breast (3 oclock position). supine with arm up breast feels fine.

Time to see doctor: It's not easy to feel a small lump, so a small lump may be palpable in one position and not in another. A mass found in a woman's breast should be examined by her primary care doctor. If cancer is suspected, special studies can be done. Treatment is more successful if a cancer is found earlier rather than later. If the mass is found not to be cancer, her doctors can offer advice and treatment too.