Staging Melanoma
Stage III Melanoma

Stage III melanomas are tumors that have spread to regional lymph nodes, or have developed in transit metastasis or satellites. There is no evidence of distant metastasis. With treatment, Stage III disease is considered to be intermediate- to high-risk for local recurrence or distant metastasis.

Stage III melanomas are defined by four primary characteristics:

  • Number of lymph nodes to which the tumor has spread.
  • Whether tumor spread to the lymph nodes is microscopic or macroscopic. Micrometastases are tiny tumors not visible to the naked eye. They can be detected only by microscopic evaluation after sentinel lymph node biopsy or elective lymph node dissection. Macrometastases can be felt during physical examination or seen with the naked eye when inspected by a surgeon or pathologist. Their presence is confirmed by lymph node dissection or when the tumor is seen to extend beyond the lymph node capsule.
  • Presence of in transit or satellite tumor.
  • Whether the primary tumor that is the source of lymph node spread shows evidence of ulceration, a condition in which the epidermis that covers a portion of the primary melanoma is not intact. Ulceration is determined by microscopic evaluation of the tissue by a pathologist, not by what can be seen with the naked eye.
Subclasses of Stage III Melanoma

Stage IIIA (T1-T4a N1aM0 or T1-T4aN2aM0)

Stage IIIB (T1-T4bN1aM0, T1-T4bN2aM0, T1-T4aN1bM0, T1-T4aN2bM0, or T1-T4a/bN2cM0)
  • T1-T4a: the tumor is not ulcerated and ranges in size from less than 1.0 mm to more than 4.0 mm thick.
  • T1-4b: the tumor is ulcerated and ranges in size from less than 1.0 mm to more than 4.0 mm thick
  • N1b: macrometastasis is diagnosed in 1 nearby lymph node
  • N2b: macrometastasis is diagnosed in 2-3 nearby lymph nodes
  • N2c: presence of in-transit metastases or satellite metastases
  • M0: the tumor has not spread to sites distant from the primary tumor
Stage IIIC (T1-4bN1bN0, T1-4bN2bM0, T1-4aN3MO or T1-4bN3MO)
  • T1-T4a: the tumor is not ulcerated and ranges in size from less than 1.0 mm to more than 4.0 mm thick.
  • T1-4b: the tumor is ulcerated and ranges in size from less than 1.0 mm to more than 4.0 mm thick
  • N1b: macrometastasis is diagnosed in 1 nearby lymph node
  • N2b: macrometastasis is diagnosed in 2-3 nearby lymph nodes
  • N3: metastasis in 4 or more lymph nodes, the presence of matted lymph nodes, or the combination of in-transit/satellite metastases and metastatic lymph nodes
  • M0: the tumor has not spread to sites distant from the primary tumor
See also Stage III Treatment.