Management of pT2a Non‑Ulcerated Melanoma with Adjacent Congenital Nevus

Surgical Excision

Perform a wide local excision with 1–2 cm lateral margins for T2 melanomas (thickness 1.01–2.0 mm) – recommended by multiple guideline bodies. Strong recommendation. [1][2][3][4]5
The European Society for Medical Oncology (ESMO) specifically advises 1 cm margins for tumors ≤2 mm thick. Strong recommendation. [1][2]
The National Comprehensive Cancer Network (NCCN) permits 1–2 cm margins, allowing the surgeon to consider anatomic site and cosmetic outcome. Moderate recommendation. [6][5]
For lesions located on the lower back, a 1–2 cm margin can be achieved without compromising function. Moderate recommendation. 6
Excision should extend to the underlying muscle fascia to ensure deep clearance. Strong recommendation. 7

SLNB is strongly recommended for pT2a melanomas to provide accurate staging. Strong recommendation. [1][2][3][4]
All major melanoma guidelines (ESMO, NCCN, UK) recommend SLNB for melanomas >1.0 mm thickness. Strong recommendation. [1][2][3][8]9
SLNB should be performed before or concomitantly with wide excision to preserve lymphatic mapping accuracy. Strong recommendation. 5
A positive SLNB upstages the disease to stage III, making the patient eligible for adjuvant systemic therapy that improves recurrence‑free and overall survival. Strong recommendation. 8
SLNB is primarily a staging and prognostic procedure; it does not itself improve disease‑specific survival. Moderate recommendation. [1][2]

Prophylactic excision of the congenital nevus is not required; guidelines advise observation unless concerning changes appear. Strong recommendation. 7
The nevus should be monitored with regular clinical examination and standardized photography. Moderate recommendation. 7
Patients should be educated to perform self‑examination of the nevus and surrounding skin. Strong recommendation. [7][2][3][4]

Routine staging imaging is not indicated for pT2a non‑ulcerated melanoma when SLNB is negative. Strong recommendation. [7][1]
UK melanoma guidelines state that stage I–II patients should not undergo routine imaging because of low true‑positive and high false‑positive rates. Strong recommendation. 7
If SLNB is positive, a contrast‑enhanced CT scan of the relevant nodal basins should be performed for further staging. Strong recommendation. [7][1]
Physical examination at follow‑up should focus on the excision site, regional lymph‑node basins, and a full skin survey for additional primary melanomas. Strong recommendation. [1][2][3][4]

Patients should be referred to a specialist skin‑cancer MDT when SLNB capability is available within the care network. Strong recommendation. 7
UK guidelines recommend MDT referral for stage IB or higher melanomas when SLNB can be performed. Strong recommendation. 7
Eligibility for clinical‑trial enrollment should be discussed at the MDT level. Moderate recommendation. [7][1]

Implement a surveillance schedule of every 3 months for the first 3 years, then every 6 months up to 5 years. Strong recommendation. [7][10]
This schedule applies to stage IB–IIIA melanomas according to UK guidelines. Strong recommendation. 7
Patients should be taught monthly self‑examination of the entire skin surface and regional lymph nodes; most recurrences are first detected by patients. Strong recommendation. 10
Routine imaging during follow‑up is not recommended unless new clinical concerns arise. Strong recommendation. [2][3]4

Discuss adjuvant therapy when SLNB is positive (stage III disease). Strong recommendation. [1][2][3][4]
Options include interferon‑α or enrollment in clinical trials of newer systemic agents. Moderate recommendation. [1][2]3
Patients with microscopic nodal involvement derive the greatest benefit from adjuvant interferon‑α. Moderate recommendation. [1][2]3
No adjuvant therapy is advised for stage IB–IIA melanoma with a negative SLNB. Strong recommendation. [1][2]

Counsel strict sun‑protection measures (avoid sunburns, limit unprotected UV exposure, including artificial sources). Strong recommendation. [2][3]4
Instruct monthly self‑examination of the skin and regional lymph nodes and provide written material on the ABCDE melanoma warning signs. Strong recommendation. [7][2][3][4]10

Stage IB melanoma (pT2a, non‑ulcerated, node‑negative) carries a favorable prognosis when managed according to guideline‑directed surgery and surveillance. Strong recommendation. [7][1]

Do not omit SLNB for melanomas >1.0 mm; it provides essential staging information that guides adjuvant‑therapy decisions. Strong recommendation. [1][8]9
Do not perform SLNB after wide excision; post‑excisional disruption of lymphatics reduces mapping accuracy. Strong recommendation. 5
Do not order routine staging CT scans for stage I–IIA melanoma; the false‑positive rate outweighs the benefit. Strong recommendation. 7
Do not prophylactically excise the adjacent congenital nevus unless it exhibits concerning clinical or dermoscopic changes. Strong recommendation. 7