Part 2
Surgical and Cosmetic Dermatology

SURGICAL DERMATOLOGY

Skin cancer

Surgical margin guidelines

Source: Adapted from Nahhas AF et al. J Clin Aesthet Dermatol. 2017 Apr; 10(4):37–46. Huang C and Boyce SM. Surgical margins of excision for basal cell carcinoma and squamous cell carcinoma. Semin Cutan Med Surg. 2004; 23:167–173.

Indication for Mohs micrographic surgery

Adapted from Ad Hoc Task Force, et al. AAD/ACMS/ASDSA/ASMS 2012 appropriate use criteria for Mohs micrographic surgery. J Am Acad Dermatol 2012; 67:531.

Location

• High risk/area “H”: “mask” areas of face (central aspect of face, eyelids [including inner/outer canthi], eyebrows, nose, lips [cutaneous/mucosal/vermillion], chin, ear and periauricular skin/sulci, temple), genitalia (including perineal and perianal), hands, feet, nail units, ankles, and nipples/areola.

  Moderate risk/area “M”: cheeks, forehead, scalp, neck, jawline, and pretibial surface.

• Low risk/area “L”: trunk and extremities (excluding pretibial surface, hands, feet, nail units, and ankles).

High‐risk tumor features

• Recurrence/incomplete prior excision
• Aggressive features (high risk of recurrence):
  • BCC: with morpheaform, fibrosing, sclerosing, infiltrating, micronodular, or metatypical/keratotic type.
    • Size: Area L > 20 mm; Area M > 10 mm; Area H > 6 mm
  • SCC with sclerosing, basosquamous, small cell, poorly/undifferentiated, spindle cell, pageotid, infiltrating, keratoacanthoma on the face, single cell, clear cell, lymphoepithelial, sarcomatoid, Breslow depth 2 mm or greater, and Clark's level IV or greater
  • Perivascular/perineural invasion
  • Other tumors: adenocystic carcinoma, adnexal carcinoma, apocrine/eccrine carcinoma, atypical fibroxanthoma, DFSP, extramammary paget disease, leiomyosarcoma, merkel cell carcinoma, and malignant fibrous histiocytoma

High‐risk patient features

• Immunocompromised (IC): transplant recipient, HIV, hematologic malignancy, or immunosuppressive medications
• Genetic syndromes: basal cell nevus, XP, and bazex syndromes
• Prior radiated skin: tumor arising in site of prior radiation treatment
• Patient with history of aggressive skin cancer with no known risk factors

Melanoma ‐ AJCC TNM classification

Major changes in AJCC eighth edition

• Round to 0.1 mm decimal for tumor depth
• Changes to T1a and T1b to 0.8 mm threshold
• Removal of mitotic rate for T category (recorded but not impacting T category)
• N category – “microscopic” vs. “macroscopic” redefined as “clinically occult” and “clinically apparent”.
• Pregnostic stage III subgroup changed (increased to IIIA–IIID)
• N subcategories revised based on number of tumor involved lymph nodes
• M1 categories changed – LDH no longer upstage to M1c, additional of CNS metastases to M1d.

Tips:

• 0.8–1.0 mm = T1b or Stage IB
• Nodal involvement → at least stage III
• Distant mets → stage IV

T classification

N classification

M classification

Adapted from AJCC Cancer Staging manual, Eighth Edition (2017). Balch CM et al. Final version of 2009 AJCC melanoma staging and classification. J Clin Oncol 2009; 27:6199–6206. Gershenwald JE et al. Melanoma staging: evidence‐based changes in the American Joint Committee on cancer eighth edition cancer staging manual. CA Cancer J...