Of the 4 types of malignant melanoma, Superficial Spreading is the most common type at 70%. It has a classic “red, white and blue” appearance.
Nodular melanoma accounts for 15% of Melanomas and has the poorest prognosis. Its appearance is blue/black dome or spike-shaped, and it may be absent of melanin, the pigment in skin that makes it appear darker.
Acral Lentiginous is the third type and involves 10% of Melanomas. It usually occurs in the palms, soles, nail beds, and mucous membranes. It affects higher age groups, has no sex predilection, and has an increased incidence in African Americans/Asians. This type also has a unique characteristic to look out for called Hutchinson’s sign or Melanotic Whitlow, which is a sudden pigmented band underneath the nail plate originating at the top nail fold and is highly suggestive of Acral Lentiginous malignant melanoma.
Lentigo Maligna is 5% of melanomas and is described appears tan with slightly raised brown/black papules. It occurs most often in the elderly and is the slowest growing of all the four types.
How can you be more aware of malignant melanoma?
Use the “ABCDEFGHI” pneumonic to learn what to look for:
- A=asymmetry. Suspicious lesions are often more irregular.
- B=border. Irregular borders are suspicious.
- C=color. Suspicious lesions are more likely to be multi-colored.
- D=diameter. Be suspicious of lesions that grow larger than a pencil eraser.
- E=examine. Most common areas are back, arms, neck and shoulders.
- F=fragility. Suspicious lesions often bleed slightly when scratched.
- G=growth. Suspicious lesions grow larger.
- H=hurt. Suspicious lesions more likely to be tender or irritated.
- I=itchy. Suspicious more likely to itch.