Cankers usually form on woody stems and may be cracks, sunken areas, or raised areas of dead or abnormal tissue. Sometimes cankers ooze conspicuously. Cankers can girdle shoots or trunks, causing everything above the canker to wilt and die. Blights and diebacks due to cankers look quite similar. Cold-injury symptoms may look like, or lead to the development of, cankers and diebacks.