Malignant Melanomas

Question 1

Superficial spreading melanoma

• which parts of the body? male vs. female?
• name the two growth phases
• histologic distribution of melanocytes
• which layer?

Answer 1

• most common melanoma
• sun-exposed skin; backs of men and lower legs of women
• radial growth, vertical growth
• buckshot scatter (pagetoid spread)
• epidermis

Question 2

Lentigo maligna/lentigo malign melanoma (-indolent, slow growing melanoma)

• where is it typically found?
• which growth phase is dominant?
• how can you tell that the lesion has become malignant?
• distinguishing cytologic features:

Answer 2

• typically found on the face of elderly
• long radial growth phase (10-50 years)
• when it’s palpable, which signals dermal invasion and vertical growth
• poorly nested and confluent melanocytes and d-e-jxn, adnexal extension, sun damage!

Question 3

acral lentiginous melanoma (least common melanoma)

• most common race
• location

Answer 3

• most common in african americans and asians

- palms, soles, beneath the nail plate *Hutchinson’s sign

Question 4

nodular melanoma

• location
• layer and growth phase
• key histologic feature

Answer 4

• anywhere
• dermis, no apparent radial growth phase, grows rapidly in the vertical direction
• atypical mitoses everywhere