Stage III Melanoma

Stage III melanomas are tumors that have spread to regional lymph nodes (there may also be in-transit or satellite involvement).  In Stage III melanoma, the depth of the melanoma no longer matters. There is no evidence of distant metastasis.

Microscoptically = seen by pathologist after biopsy or dissection
Macroscoptically = seen by naked eye or felt by hand

Stage III: Melanoma 'regional spread'

Subclasses IIIA, IIIB, IIIC

Defined by number of lymph nodes to which it has spread

It can, but it need not have ulceration

Different whether the spread to the lymph nodes, can be detected microscoptically or macroscoptically

Risk: Intermediate to high for occurring again in the same spot or spreading to distant sites

Stage III Melanomas Are Defined By 3 Primary Characteristics:

  •  Number of lymph nodes to which the tumor has spread
  •  Whether the tumor spread to the lymph node 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.
  • Ulceration: when the epidermis (or top layer of skin)  that covers a portion of the primary melanoma is not intact. Ulceration can only be seen under a microscope, not by the naked eye.

There Are 3 Subclasses of Stage III Melanoma

Stage IIIA

T1-T4aN1aM0 or T1-T4aN2aM0

  • T1-T4a: tumor of any thickness with no ulceration
  • N1a: micrometastasis to 1 nearby lymph node
  • N2a: micrometastasis to 2-3 nearby lymph nodes
  • M0: No evidence of metastasis to distant sites

Stage IIIB

T1-T4bN1aM0, T1-T4bN2aM0, T1-T4aN1bM0, T1-T4a/bN2bMO, or T1-T4a/bN2cMO

  • T1-T4a: tumor of any thickness, with no ulceration
  • T1-T4b: tumor of any thickness with ulceration
  • N1a: macrometastasis to 1 nearby lymph node
  • N2a: macrometastasis to 2-3 nearby lymph nodes
  • N1b: macrometastasis to 1 nearby lymph node
  • N2b: macrometastasis to 2-3 nearby lymph nodes
  • N2c: presence of in-transit metastasis or satellite metastasis
  • M0: no evidence of metastasis to distant sites

Stage IIIC

T1b-4bN1bM0, T1-T4bN2bM0, T1-T4a/bN3M0

  • T1-T4a: tumor of any thickness with no ulceration
  • T1-T4b: tumor of any thickness with ulceration
  • N1b: macrometastasis to 1 nearby lymph node
  • N2b: macrometastasis to 2-3 nearby lymph nodes
  • N3: metastais in 4 or more lymph nodes, the presence of matted lymph nodes or the combination of in-transit/satellite metastases and metastic lymph nodes
  • M0: No evidence of metastasis to distant sites

Risk: With treatment, Stage III disease has an intermediate to high risk for local recurrence or distant metastasis. Even within Stage III, the earlier the melanoma is found and treated, the better the outcome. Keep in mind that the statistics shown for survival are averages; everyone’s cancer and survival rate is based on many factors and determined on an individual basis.

Read more about Stage III Follow-up

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