What are these pea-sized lumps in my abdomen?

[JeanellOrtiz]

Hi,

Three months ago, I experienced a burning sensation in my stomach and pain two inches above my navel. In that spot, I noticed a pea-sized lump that was tender to touch. A couple of weeks later, I experienced pain in other spots in my abdomen and noticed many more lumps. Some of the lumps are not tender to touch anymore, but all are still there. They feel hard and immobile. I've had the following tests done:

Upper Endoscopy- Showed a small hiatal hernia, Schatzki's ring and chronic gastritis.  
Upper right quadrant abdominal ultrasound- Clear
Abdominal CT scan- Clear
CBC- Normal, except low on B12
CHEM 20- Normal
Thyroid blood test- Normal
H.pylori stool test- Negative

I've seen many doctors and I still don't have answers. What could these lumps be? Is there any other test I should get done? What doctor could perform a biopsy on them?

Thank you in advance!