24 Melanoma of the Skin
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SUMMARY OF CHANGES
• Melanoma thickness and ulceration, but not level of invasion, are used in the T category (except for T1 melanomas).
• The number of metastatic lymph nodes, rather than their gross dimensions, and the delineation of clinically occult (i.e., microscopic) vs. clinically apparent (i.e., macroscopic) nodal metastases are used in the N category.
• The site of distant metastases and the presence of elevated serum lactic dehy- drogenase (LDH) are used in the M category.
• All patients with Stage I, II, or III disease are upstaged when a primary melanoma is ulcerated.
• Satellite metastases around a primary lesion and in-transit metastases have been merged into a single staging entity that is grouped Stage IIIc disease.
• A new convention for defining clinical and pathologic staging has been devel- oped that takes into account the new staging information gained from intra- operative lymphatic mapping and sentinel node excision.
C44.0 Skin of lip, NOS C44.1 Eyelid C44.2 External ear C44.3 Skin of other and
unspecified parts of face
C44.4 Skin of scalp and neck C44.5 Skin of trunk C44.6 Skin of upper limb
and shoulder
C44.7 Skin of lower limb and hip C44.8 Overlapping lesion of
skin C44.9 Skin, NOS
C51 Vulva
C51.0 Labium majus C51.1 Labium minus C51.2 Clitoris
C51.8 Overlapping lesion of vulva
C51.9 Vulva, NOS
C60 Penis
C60.0 Prepuce C60.1 Glans penis C60.2 Body of penis C60.8 Overlapping lesion of
penis C60.9 Penis, NOS C63.2 Scrotum, NOS
INTRODUCTION
Melanoma of the skin continues to increase in frequency, with 47,700 new cases and 9,200 deaths expected in 2005 (1). Melanoma can arise from skin anywhere on the body. It occurs most commonly in fair-skinned persons, especially those with a history of significant sun exposure.
A completely revised melanoma staging system is provided herein, along with operational definitions. In addition, a major database analysis of prognos- tic factors involving 17,600 cancer patients from 13 cancer centers and organi- zations was performed to validate the staging categories and groupings (2).
Within each stage grouping and its subgroups, there is a uniform risk for distant
metastases and a uniform survival probability. This revised version of melanoma
staging more accurately reflects the prognosis and natural history of melanoma
and will therefore be more applicable to treatment planning and clinical trials
involving melanoma.
ANATOMY
Primary Sites. Cutaneous melanoma can occur anywhere on the skin. It occurs most commonly on the extremities in females and on the trunk in males. Mela- nomas located on the palms, soles, and nailbeds (acral lentiginous melanoma), although they occur infrequently, are distinctive because they can occur in individuals of any ethnic origin and in persons with no history of significant sun exposure.
Regional Lymph Nodes. The regional lymph nodes are the most common site of metastases. The widespread use of cutaneous lymphoscintigraphy, lymphatic mapping, and sentinel lymph node biopsies has greatly enhanced the ability to identify the presence or absence of, and to stage, nodal metastases. Intralym- phatic regional metastases may also become clinically manifest either as satellite metastases (defined arbitrarily as intralymphatic metastases occurring within 2 cm of the primary melanoma) or as in-transit metastases (defined arbitrarily as intralymphatic metastases occurring more than 2 cm from the primary melanoma but before the first echelon of regional lymph nodes). By convention, the term regional nodal metastases refers to disease confined to one nodal basin or two contiguous nodal basins, as in patients with nodal disease in combina- tions of femoral/iliac, axillary/supraclavicular, cervical/supraclavicular, axil- lary/femoral, or bilateral axillary or femoral metastases.
Metastatic Sites. Melanoma can metastasize to virtually any organ site. Metas- tases most commonly occur in the skin or soft tissues, the lung, and the liver.
DEFINITIONS Primary Tumor (T)
TX Primary tumor cannot be assessed (e.g., shave biopsy or regressed melanoma)
T0 No evidence of primary tumor Tis Melanoma in situ
T1 Melanoma £1.0mm with or without ulceration (Figures 24.1A–D) T1a Melanoma £1.0mm in thickness and level II or III, no ulceration (Figure
24.2)
T1b Melanoma £1.0mm in thickness and level IV or V or with ulceration (Figures 24.3A, B)
T2 Melanoma 1.01–2.0 mm in thickness with or without ulceration T2a Melanoma 1.01–2.0 mm in thickness, no ulceration (Figure 24.4) T2b Melanoma 1.01–2.0 mm in thickness, with ulceration (Figure 24.5) T3 Melanoma 2.01–4.0 mm in thickness with or without ulceration T3a Melanoma 2.01–4.0 mm in thickness, no ulceration (Figure 24.6) T3b Melanoma 2.01–4.0 mm in thickness, with ulceration (Figure 24.7) T4 Melanoma greater than 4.0 mm in thickness with or without ulceration T4a Melanoma >4.0mm in thickness, no ulceration (Figure 24.8)
T4b Melanoma >4.0mm in thickness, with ulceration (Figure 24.9) Regional Lymph Nodes (N)
NX Regional lymph nodes cannot be assessed
N0 No regional lymph node metastasis
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Epidermis
A B
C D
Papillary dermis Reticular dermis Subcutaneous tissue
Clark level IV Clark level V
Epidermis Papillary dermis Reticular dermis
Subcutaneous tissue
