stage I Merkel cell carcinoma
(stayj ... MER-kul sel KAR-sih-NOH-muh)
Stage I Merkel cell carcinoma is divided into stages IA and IB. In stage IA, the tumor is 2 centimeters or smaller at its widest point and no cancer is found when the lymph nodes are checked under a microscope. In stage IB, the tumor is 2 centimeters or smaller at its widest point and no swollen lymph nodes are found by a physical exam or imaging tests.