I have 2 marble sized hard lumps under skin of stomach. one by my rib and one under rib, same side. doctor says not worry. what could it be?

See a dermatologist : I believe these could be fat necrosis, granulomas, keloids, healed over abscesses, or other more serious possibilities come to mind. The only way to narrow the possibilities is to see a dermatologist, if your PCP did not diagnose these specifically. Many of the possibilities I described above require no treatment, but it takes a derm to sort them out for you...

Lipoma: Lipomas are benign collections of fat tissue, often found in the stomach. They are firm but squish. A sure way to find out would be to excise one. A very easy procedure perfromed in an outpatient office

Marbles: The differential diagnosis on what you describe is so lengthy and variable that a short answer will not suffice. However, the worst thing you could do is ignore these findings. The best thing you could do is get an opinion from another physician (not associated with your physician) just to make sure. This doesn't mean your physician is wrong. It just means if you are asking us you are concerned.

Hard to say: But I would suspect that the "lumps" are lipomas, benign lesion made of fat cells. Again it's hard to say without seeing/feeling the lesions myself, but this is one of the more commonly found lesions under the skin. Remember as your own patient advocate, make sure you understand the diagnoses that your doctor is giving you, including actual specifics(as in terms). Best of luck.

It could be: a benign cyst or lipoma or calcified carbuncle. Observe for change size or pain. If still concerned a general surgeon or PCP can have it excised for biopsy