stage I melanoma

Definition of stage I melanoma
National Cancer Institute

stage I melanoma

(... MEH-luh-NOH-muh)
Stage I is divided into stages IA and IB. In stage IA, the tumor is not more than 1 millimeter thick, with or without ulceration (a break in the skin). In stage IB, the tumor is more than 1 but not more than 2 millimeters thick, without ulceration.

Source: NCI Dictionary of Cancer Terms