Melanoma

Yesterday my wife was diagnosed with Melanoma via a pathology test and then with a consultation with a skin cancer specialist Dr Robyn Saw. Apparently it is 4mm deep, is this whats referred to as a grade 4 Melanoma?
The doctor is suggesting removal of it from the shin on her leg with a 5cm skin graft and also selective lymph node dissection.
Obviously we are both very worried about it and now have to wait just over a week before surgery on the 27th. Does the appearance of cancer cells in a lymph node suggest it has spread to other organs?
I've heard surviving a grade 4 Melanoma is rare. I cant seem to find any good Q&A sites on what we can expect for the future. Any advice or help would be greatly appreciated.

Regards
Sven

[Fernando Roque, MD]

Hi.  The tumor grade does not refer to the depth in which the tumor has extended.  Rather, it has something to do with how normal-looking the cancer cells are.  If the melanoma cells still have a good resemblance to normal melanocytes (skin pigment cells), then they are considered as low grade tumors and are assigned a lower number (1 or 2).  A grade 4 melanoma means that it is a high grade tumor and is very abnormal in appearance.  Tumor grade connotes the aggressiveness of the tumor and its tendency to grow and spread to other areas.  The higher the grade, the more aggressive the cancer is likely to be.  I also would like to point out that the tumor grade should not be mistaken for the STAGE of the cancer.  The stage indicates how big the cancer has grown and how extensive it has spread in the body.  Stage 4 disease means spread to distant body organs, and is usually incurable.  This is probably what you're referring to when you said that "surviving grade 4 melanoma is rare".  You probably mean stage 4 melanoma, not grade 4.  

The appearance of cancer cells in a lymph node does not necessarily indicate spread to other organs.  Usually it still means a localized form of the disease, but if there is already spread to nearby nodes, the risk of eventual metastases to distant organs is increased.

[audioslave62]

Thanks for your explanation, most appreciated.
We'll just play the waiting game now until the 27th for the Op and then 10 days after for the result.

Regards
Sven