Rarely. Although benign cysts are very common, they are seldom cancerous.
Nevertheless, it is important to check to make sure the lump is a cyst and not something else. Many women get what are called cyclical lumps, or lumps that appear sometime before the start of the menstrual cycle, and later shrink or disappear. Cyclical lumps are generally harmless, but they should also be monitored. Pay attention to benign cysts and cyclical lumps, and be sure to check in with your healthcare provider.
Never assume that a new lump or abnormality of the breast is a cyst, just because you have had breast cysts in the past. You should always check in with your doctor to make sure the lump or abnormality is not something else.