Skin Cancer Crash Course: Part 1: Spotting Spots – Recognizing Moles, Melanoma and Mimickers
Hensin Tsao, MD PhD Massachusetts General Hospital Disclosures
If you have disclosures, state: “I have the following relevant financial relationship with a commercial interest to disclose:” Epiphany Dermatology Lazarus UpToDate Skin Cancers
• Skin cancers – Keratinocyte-derived • Basal cell carcinoma • Squamous cell carcinoma – Melanocyte-derived • Melanoma – Merkel cell carcinoma – Cutaneous lymphomas – Rare skin cancers Cutaneous Melanoma
• Clinical Background – Younger median age: around 50 years – 2021: 106,110 cases of cutaneous melanoma – Males: 1:27 lifetime chance of melanoma – Females: 1:40 lifetime chance of melanoma – Men > Women – Rate of growth variable (weeks to years) • Risk factors include: – Family history of melanoma – Light complexion and sun burns (before 20) – Tanning beds – Many moles
Moles
• Congenital Moles – Present, by definition, at birth or soon after – May range in size from < 1 cm to involvement of large surface areas – Brown to blue areas with pebbly surface and occasionally increased hair – May degenerate into cutaneous or central nervous system melanoma
Moles
• Acquired Junctional Moles – Even tan to brown/black macule or minimally- elevated plaque with sharp borders and symmetry
• Acquired Compound and Dermal Moles – Usually elevated dome shaped papule or plaque with even shades of brown pigmentation
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Moles
• Acquired Atypical (Dysplastic) Moles – Cells with atypical morphology – Tan to brown to dark brown/black macules and thin plaques – May lack sharp borders or symmetry – May be a precursor to melanoma Junctional Dysplastic
Mild-moderate atypia
Scar (regression)
Dermal nevus Cutaneous Melanoma
• Superficial spreading melanoma – ~70% of all cutaneous melanomas – Median age: 30 to 50 years – Usually located on trunks of men and lower extremities of women (? intermittent sun exposure) – Asymmetric plaque with variations in color and irregularities of border – Papular or nodular component suggest deeper invasion – Can arise from precursor moles
Cutaneous Melanoma
• Nodular Melanoma – ~15% of all cutaneous melanomas – Median age:40 to 50 years – Distribution similar to SSM but onset more rapid – Papule or nodule with colors ranging from red to blue/black with occasional surface ulceration – May have sharp borders, even coloration and symmetry – Precursor moles not commonly found
Cutaneous Melanoma
• Acral Lentiginous Melanoma – ~10% of all cutaneous melanomas – Median age: 60 to 65 years – Not sun related (? Trauma) – Located on palms/soles and nail apparatus – Predominant variant in Asians and African- Americans – Dark brown/black macular lesion with foci of plaque or nodule formation – Borders may be extremely ill defined with areas of regression
Photos courtesy of Karen Roh, MD www.clevelandlclinicmeded.com Cutaneous Melanoma
• Lentigo Maligna – Slowly growing premalignant lesion – Between 5-30% become melanoma – Occurs predominantly on head and neck – Completely macular lesion with tremendous variation in color and irregularity of border (“stain”) – Surface usually unaltered
Cutaneous Melanoma
• Lentigo Maligna Melanoma – Accounts for 5-10% of all cutaneous melanomas – Median age at diagnosis is 65 to 70 years – Usually related to cumulative sun exposure and thus occurs on sun exposed areas – Typically macular component (Lentigo Maligna) and a papular or nodular component signifying invasion
Cutaneous Melanoma
• Amelanotic melanoma – Uncommon variant (<10%) – Occurs more frequently in patients with red hair and sparse pigmentation – Most frequently misdiagnosed as basal cell carcinoma – Usually pink papule or plaque
Cutaneous Melanoma
• Desmoplastic melanoma – About 2-3% of melanomas – More common on head/neck – Usually firm dull red or brown papules or plaques in a firm matrix
Cutaneous Melanoma
• Cutaneous metastases – Can be brown, blue or pink – Can occur as a single lesion or as a crop of papules/nodules – Be particularly suspicious of new lesions • Next to the primary site • In the lymphatic drainage pattern
Cutaneous Melanoma
• Mimics – Nevus – Non-melanoma skin cancer – Seborrheic keratoses – Lentigo – Miscellaneous • Eczema • Dermatofibroma Mimics
J Am Acad Dermatol. 2019 Jan;80(1):178-188 Summary
• Early thin melanomas may not follow textbook pictures • Clinical picture of common lesions (e.g seb kers, dysplastic nevi) often overlaps with melanoma • When in doubt, cut it out • No need to remove all moles; will minimally reduce risk of future melanomas • Patients with high density of clinically atypical moles should be referred to dermatologist Cutaneous Melanoma
• Quiz Question 1
1 2 Question 2
1 2 Question 3
1
2
3
4 Question 4
2
1 Question 5
1 2 Question 6
2 1
4 7 5 3
6 Question 7
Level 7
A B
C D Question 8
A B
DF-like CMM 7.3mm
C D