A lump in the palm of the hand is often the result of benign tumor, a bone spur or a foreign body, such as a splinter, under the skin, advises Massachusetts General Hospital. Dupuytren's contracture is another possible cause of a lump in the palm of the hand, states WebMD.
Tumors that appear on the palm of the hand include ganglion cysts, giant cell tumors of a tendon sheath, epidermal inclusion cysts, lipomas and neuromas, states Masschusetts General Hospital. Hand cancer is rare; skin cancers are the most common malignancies that appear on the hands. Additionally, cancer sometimes spreads from other parts of the body, such as the lung or breast.
Dupuytren's contracture is a hand deformity that develops over a number of years, explains Mayo Clinic. Knots of tissue develop beneath the skin and form a thick cord that pulls the fingers into a bent position.