Fung II

Question 1

T/F: Benign or malignant neoplasms can only arise in the epidermis

Answer 1

False; they can arise from any component of the skin, including epidermis (squamous or melanocytic), dermis, or adnexal

Question 2

What is this:

neoplasm of unknown origin; no malignant potential; round flat coin-like lesion that is waxy

Answer 2

sebhorreic keratosis

Question 3

What are some microscopic observations for skin tags?

Answer 3

loose stroma surrounded by epidermis; papillomatosis

Question 4

Deposition of collagen in the formation of a scar; common in African Americans

Answer 4

keloids (hypertrophic scars)

Question 5

What will you see microscopically with keloids?

Answer 5

keloidal collagen

Question 6

This benign epithelial tumor will invaginate into the dermis and can rupture and allow keratin to spill out into the surrounding area

Answer 6

epidermal inclusion cyst

Question 7

This premalignant tumor is due to sun damage; causes hyperkeratosis of skin leading to tan/brown skin lesions that feel like sand paper

Answer 7

actinic keratosis

Question 8

Does actinic keratosis extend to the whole epidermis?

Answer 8

no

Question 9

What is a characteristic microscopic feature of actinic keratosis?

Answer 9

atypical keratinocytes with abnormal nuclei (large and dark)

Question 10

What is a characteristic microscopic feature of squamous cell carcinoma in situ?

Answer 10

full thickness atypical cells in epidermis

Question 11

What are two features of squamous cell carcinoma that we should keep in mind?

Answer 11

intracellular bridges
atypical keratinocytes (dark, large nuclei)

Question 12

How does basal cell carcinoma typically present?

Answer 12

pearly, pigmented papules; locally aggressive tumor often occurring on the face

**can erode into the bone if not taken care of

Question 13

What are three characteristic features of a basal cell carcinoma?

Answer 13

peripheral palisading
stromal retraction
horn cysts

**can be pigmented

Question 14

In what condition is solar elastosis seen?

Answer 14

melanocyte neoplasms

Question 15

What is the spectrum of melanocytic neoplasms from benign to malignant?

Answer 15

nevus
dysplastic nevus
melanoma

Question 16

Common benign neoplasms that are acquired by activating mutations in the Ras signaling pathway

Answer 16

nevus

Question 17

Nevus(es) are considered neoplasms. Why?

Answer 17

because they are acquired by a mutation in the Ras signaling pathway

Question 18

What are the three morphological phases that a nevus can progress through, and how are they different?

Answer 18

junctional nevus: flat, nevoid cells only in epidermis
compound nevus: more mature, raised, nevoid cells in dermis and epidermis
intradermal nevus: only in dermis

Question 19

What is a difference between a nevus and a melanoma?

Answer 19

melanomas do not progress through morphologic phases; also, melanomas do not have the P16 checkpoint (which keeps nevuses from proliferating too much)

Question 20

May be direct precursors of melanoma
Vast majority are stable and never progress
Have acquired activating mutations in NRAS and BRAF genes

Answer 20

dysplastic nevus

Question 21

What genes acquire mutations in a dysplastic nevus?

Answer 21

NRAS

BRAF

Question 22

Most deadly of all skin cancers, but can be cured if detected in its early stages
Mostly occurs on the skin but can occur within the mucosa

Answer 22

melanoma

Question 23

Melanomas can be genetic (10-15%) or sporadic (due to UV radiation. How can UV radiation cause melanoma?

Answer 23

disrupts cell cycle control genes
activates pro-growth signaling pathways
activates telomerase

Question 24

What are the two growth phases in melanoma?

Answer 24

radial - grows just in the epidermis

vertical - grows through the basement membrane of the epidermis to the dermis

Question 25

If you see hyperplasia of the sebaceous glands, what type of neoplasm is this considered?

Answer 25

adnexal

Question 26

What is a pilar cyst?

Answer 26

a cyst of hair follicles with compact keratin inside the cyst

Question 27

What is pilomatricoma?

Answer 27

a pilar cyst with calcifying of the lesion

**look for shadow cells

Question 28

When would you see a pigmented basal layer, spindle cells, and keloidal collagen?

Answer 28

dermatofibroma

**DFSP penetrates further into the dermis