Skin melanoma T1-T4NxMx

SKIN  MELANOMA is a malignant tumor of melanocytic origin. Predecessors of melanoma are melanocellular (nevo-cellular) nevi, a tumor can develop from common melanocytes after ultra-violet burns.

There are following clinical forms: surface spread melanoma, melanoma – lentigo, nodular melanoma, primary amelanotic melanoma.

Surface spread melanoma is a pigmented spot or a plaque of irregular shape with uneven edges and irregular distribution of pigment. Over the first years the spot is growing only within the limits of the epidermal layer (horizontal growth phase), then an elevated area is developing on the background of the spot (vertical growth phase). During the vertical growth phase the surface may become ulcerated and covered with crusts.

Lentigo-melanoma is a papule or a nodule on a flat spot of a black, brown or often mottled color. It develops from melanosis Dyubreya and may remain in the horizontal growth phase for over 10 years.

Nodular melanoma is a smooth brown or blue-black node. The horizontal growth phase of nodular melanoma is short; most tumors are revealed at the vertical growth phase, which is unfavorable for the disease prognosis. Nodular melanoma can lose its potential for melanin synthesis and thus become colorless. This is an extremely unfavorable symptom of low differentiation of tumor cells and therefore increasing tumor malignancy.

Primarily amelanotic melanoma is a melanoma which genetically has no potential for melanin synthesis.  This is a papule or a spot of a pink or red color that does not change color in diascopy.  As a rule, this melanoma type is diagnosed too late because it is often misunderstood as a benign lesion.

The traditional surgical excision of melanoma grade I and II has a number of serious shortcomings. The removal of the skin fascial flap creates a huge defect, which is difficult or often impossible to cover by local tissue. Healing proceeds with formation of rough scars.  Nevertheless, despite a broad excision high percentage of recurrences is registered in the post-operative site of the scar.  And what is most serious, surgical intervention provokes tumor micrometastases growth because it breaks the negative feedback between the primary tumor and metastases! According to up-to-date knowledge about melanoma the excision of a skin flap with tumor is an anachronism that still exists due to inertia and conservatism of medical luminaries who stiffly reject the obvious fact that the long-term melanoma therapy results depend on the clinical-morphological tumor characteristics, but not on the aggressiveness of the surgery.  

Alternative to surgery is Photodynamic therapy. Unlike surgical excision Photodynamic therapy affects tumor cells selectively and results in formation of a photonecrotic  area in the tumor site. Photonecrosis resorbs as a result of macrophage function presenting melanoma antigens to lymphocytes that leads to immune response to melanoma. Thus, not only the primary tumor disappears, but also immune reaction develops against its metastases. Therefore no local relapses appear after PDT in contrast to surgical excision even in patient with advanced melanomas! The analysis of long-term results showed that patients with melanoma treated by PDT have 3-fold higher opportunity to survive five-year period than those who underwent surgery.

Prophylactics of melanoma implies timely removal of large nevi and other, in particular, congenital atypical pigmented lesions. This is incomparably easier than melanoma treatment.

Disease prognosis depends on the thickness of primary tumor and detected metastases (see the table)

Relation of the 5-year survival to clinical stage of melanoma and the level of invasion by Breslow in surgical treatment.

Clinical stage

Tumor thickness by Breslow, mm

5-year survival, %

 Ia tumor localizes in the primary lesion

 Less than 0.75

 96

 Ib

 0.76-1.5

 87

 IIa

 1.5-2.49

 75

 IIb

 2.5-3.99

 66

 IIc

 over 4

 47

 III metastases in regional lymph nodes

 

47-45 (with one lymph node involved)

Less than 20 (with two lymph nodes involved)

 IV (distant metastases)

 

Patients live less than 1 year

 

Skin melanoma (thickness by Breslow 0.75 mm, invasion by Clark I).
Lentigo-melanoma of the back skin (invasion by Clark III).