Fast Five Quiz: Melanoma and Other Skin Cancers

William James, MD


July 01, 2021

According to current AAD guidelines, the preferred biopsy technique for primary cutaneous melanoma is a narrow excisional/complete biopsy with 1- to 3-mm margins that encompass the entire breadth of lesion and is of sufficient depth to prevent transection at the base. This may involve fusiform/elliptical or punch excision or deep shave/saucerization removal to a depth below the anticipated plane of the lesion.

The AAD guidelines discourage routine molecular testing, including gene expression profiling. They also state that the application of molecular information for clinical management is not recommended outside of a clinical study or trial. Testing of the primary cutaneous melanoma for oncogenic mutations (eg, BRAF, NRAS) is not recommended in the absence of metastatic disease.

According to the AAD guidelines, sentinel lymph node biopsy is not recommended for patients with melanoma in situ or for most T1a cutaneous melanomas (< 0.8 mm without ulceration). Sentinel lymph node biopsy should be discussed and offered to appropriate patients with cutaneous melanomas with a thickness > 1 mm (T2a or higher), including T4 cutaneous melanomas. In patients with T1b cutaneous melanoma (< 0.8 mm with ulceration or 0.8-1 mm with or without ulceration), sentinel lymph node biopsy should be discussed and considered; however, rates of sentinel lymph node biopsy positivity are still relatively low. Sentinel lymph node biopsy may be considered for T1a cutaneous melanoma if other adverse features are present, including young age, presence of lymphovascular invasion, positive deep biopsy margin (if close to 0.8 mm), high mitotic rate, or a combination of these factors.

Read more about the workup of melanomas.


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