Dermatopathology 04

Question 1

Beside Vitiligo and Albinism what are 2 other hypopigmentation disorders that we covered?

Answer 1

post-inflammatory hypopigmentation

Piebaldism

Question 2

What is post-inflammatory hypopigmentation caused by?

Answer 2

result of cutaneous inflammation, injury or dermatological treatment

Question 3

What is the pathogenesis of Piebaldism?

Answer 3

Mutation in KIT port-oncogene

Leads to abnormal melanocyte migration from the neural crest leading to leukoderma (white skin) affecting central forehead, central frontal scalp etc

Question 4

Poliosis

Answer 4

white hair

Question 5

What is a major characteristic feature of freckles as far as how the present on skin?

Answer 5

fade and darken in cyclic fashion during winter and summer

Question 6

Pathogenesis of freckles?

Answer 6

Hyperpigmentation results from increased amounts of melanin pigment within basal keratinocytes, not an increase in the number of melanocytes

Question 7

Histologically Cafe au lait spots are similar to what condition?

Answer 7

freckles

Question 8

Are Cafe au lait spots affected by sun exposure?

Answer 8

no

Question 9

Pathogenesis of Cafe au lait spots.

Answer 9

increased melanocyte density and macro-melanosomes

Question 10

What conditions is are Cafe au lait spots most linked to?

Answer 10

neurofibromatosis

McCune-Albright syndrome (coast of Maine appearance)

Noonan syndrome

Question 11

What is the prognosis of Cafe au lait spots?

Answer 11

do not cause mortality or morbidity

don’t undergo malignant change

Question 12

Be able to reproduce chart on the different nevus variants, their features and clinical significance.

Answer 12

Reproduce chart.

Question 13

Why do nevi only rarely give rise to melanomas?

Answer 13

• Oncogene-induced senescence: expression of activated RAS or BRAF in normal human melanocytes
  causes only a limited period of proliferation, followed by a permanent growth arrest mediated by
• This protective response is disrupted in melanoma
  accumulation of p16/INK4a, a potent inhibitor of cyclin-dependent kinases (CDK4 and CDK6

Question 14

What is the condition being evidenced in this image?

Answer 14

dysplastic nevus

Question 15

What are the 3 types of radial growth phase in melanoma?

Answer 15

1. Lentigo maligna
2. Superficial spreading
3. Acral/mucosal lentiginous melanoma

Question 16

What is lentigo malignant?

Answer 16

Indolent lesion on the face of older men that may remain in the radial growth phase for several decades

Question 17

What is superficial spreading in the radial growth phase characteristic of melanoma?

Answer 17

the most common type of melanoma, usually involving sun-exposed skin

Question 18

What is acral./mucosal lentiginous melanoma unrelated to?

Answer 18

sun-exposure