Level 1 melanomas are almost always curable by surgical removal of the lesion . Levels 4 and 5 recur in about
50 percent of cases. Level 3 melanomas recur in perhaps 20 percent of patients.
Another classification system (Breslow level) using the exact measurement of the thickness of the tumor under the microscope has recently been introduced and is used together with the other system.
Melanomas less than 1.5 mm are usually considered highly curable by surgery alone, although some people with such "thin" lesions have had recurrences. Tumors 1.6 mm to 4 mm are considered to have a moderately deep invasion and have a worse prognosis than thin lesions. Melanomas over 4 mm recur in over 50 percent of individuals.
While no exact relationship exists between the two classification schemes, an approximate correlation can be made between levels and thicknesses.
It is prudent to consider any lesion deeper than 1 mm potentially recurrent. Close contact with the surgeon or a medical oncologist for follow-up examinations is required in these circumstances.
The presence of the tumor in regional lymph nodes draining the site of the primary tumor , such as the lymph nodes in the armpit draining a melanoma of the forearm, is another sign of a poor prognosis. If one to three lymph nodes contain metastases from melanoma, cure is still possible by surgically removing the lymph nodes. If four or more lymph nodes contain metastatic melanoma, recurrences elsewhere in the body become quite common.
