1. Small lump on your palm (not on the dorsum side) of your hand which is painless can be thickening of the palmar fascia - Dupuytren's contracture or it can just be a small callosity due to friction,
2. Cause is mostly unknown, but is associated with alcohol, liver
diseases, diabetis mellitus, etc.
3. Dupuytren's contracture may lead to limitation of finger movements which might require intervention like local steroid/ collagenase injection or surgical release,
4. Taking an Xray of hand will help us rule-out other possibilities arising from the bones,
might help you to maintain mobility of fingers. You can continue to routine activities.