Large congenital nevus. (With permission from Mulholland MW, Lillemoe KD, Doherty GM, Maier RV, Upchurch GR, eds. Greenfield’s Surgery. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2005.)
Congenital Nevi
•1% of children are born with congenital nevi
•Lifetime risk of progression from congenital nevus to melanoma is dependent on the lesion’s size
•Classified as small <1.5 cm, medium-sized 1.5 to 20 cm, and large >20 cm
•Lesions <1.5 cm have a less than 1% chance of progressing to melanoma
•Lesions >20 cm have a 4.5% to 10% lifetime risk of progressing to melanoma
•Many of these will develop into melanoma in the first few years of life and therefore early excision is warranted
There is a spectrum of management strategies for congenital nevi based on size: large lesions (greater than 20 cm) should be excised early in life, while small lesions (less than 1.5 cm in size) have a minimal chance of progression and should be carefully observed.
A 45-year-old male has a 1.5-mm-thick melanoma on his right arm, without any axillary lymphadenopathy or abnormalities on chest X-ray. His liver function tests are normal. CT scans of the abdomen and pelvis are obtained and are negative for any distant metastases. What is this patient’s TNM classification?
This patient’s lesion has an American Joint Committee on Cancer (AJCC) TNM classification of T2, N0, M0.
Melanoma TNM Classification
•Based on the American Joint Committee on Cancer (AJCC) classification
•Tumor (T)
•For T1 lesions, T status is further designated “a” or “b” based on < or ≥ 1 mitosis/mm2
•T2 = 1 to 2 mm
•T3 = 2 to 4 mm
•T4 = >4 mm
•For all lesions, T status is further designated “a” or “b” based on ulcerated or non-ulcerated
•Node (N)
•N0 = No affected nodes
•N1 = One affected node
•T status is further designated “a” or “b” based on micro- or macrometastases
•N2 = Two or three nodes or in-transit lesion with negative LNs
•T status is further designated “a,” “b,” or “c” based on micro- or macrometastases, or in-transit lesion with negative LNs
•N3 = Four or more nodes; matted LNs or in-transit lesion with positive LNs
•Metastasis (M)
•M0 = No metastases
•M1a = Distant skin or distant lymph node metastases
•M1b = Any lung metastases
•M1c = All other visceral metastases or distant metastases, or any patient with any metastases with an elevated LDH
•Further subdivisions exist based on metastasis size
A 50-year-old male with a 2-mm-thick melanoma on his leg has two enlarged inguinal lymph nodes. A chest X-ray is normal. What is his clinical stage?
This patient’s lesion has an American Joint Committee on Cancer (AJCC) TNM classification of T2, N2, M0, which is classified as clinical stage III.
Melanoma Staging
•Based on TNM classification of disease
•Staging should be used following complete excision of the primary melanoma and clinical and radiologic evaluation for metastases
•Stage 0: in situ disease only
•Stage I: T1 or T2; no nodal disease
•Stage II: T2 with ulceration, or T3 or T4; no nodal disease
•Stage III: Any nodal disease
•Stage IV: Any metastatic disease
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