I have a large lump on my right toe. it is on the underside of the foot. they think it is in my joint. tried a steroid shot 3 weeks ago and no pain?

Foot pain: If this steroid shot gave no relief, I recommend an ultrasound and/or an x-ray to better evaluate the bone, and other structures. You also try an anti-inflammatory medication. If concerned I would see a rheumatologist and would be happy to do a consult if needed.

Varies: There are a number of possible causes. Some patients will have a subtle foot deformity that can cause a callus to appear on the undersurface if the toe. Inflammatory conditions that involve the joint can also cause areas like you are describing as can benign tumors. I would certainly continue followup through a foot specialist to ensure accurate diagnosis and treatment.