Lecture 181

Question 1

What are seborrheic keratoses (SK)?

Answer 1

Round, flat plaques of varying sizes, uniformly tan to brown with a velvety surface, appear ‘stuck on’ and may seem peelable.

Question 2

What is the Leser-Trelat sign?

Answer 2

A rapid increase in the number of seborrheic keratoses can be a marker for underlying adenocarcinoma.

Question 3

Which mutations may play a role in seborrheic keratoses?

Answer 3

Activating mutations in FGFR3.

Question 4

What histological features are characteristic of seborrheic keratoses?

Answer 4

Horn or pseudo-horn cysts and inflamed lesions showing foci of ‘whorling’ squamous cells.

Question 5

What is acanthosis nigricans?

Answer 5

Thickened, hyperpigmented skin, typically in flexural areas, caused by increased growth factors.

Question 6

What is malignant acanthosis nigricans associated with in older individuals?

Answer 6

Adenocarcinoma.

Question 7

What describes the appearance of acanthosis nigricans?

Answer 7

Repeating peaks and valleys in the skin surface, hyperkeratosis, and pigmentation concentrated in the basal cell layer.

Question 8

What is a fibrovascular core covered by benign squamous epithelium?

Answer 8

Fibroepithelial polyp (skin tag).

Question 9

What are epithelial cysts?

Answer 9

Well circumscribed, firm, moveable, dome-shaped nodules formed by downgrowth and cystic expansion of the epidermis or hair follicle epithelium, filled with keratin.

Question 10

What type of epithelial cyst resembles normal epidermis?

Answer 10

Epithelial inclusion cyst.

Question 11

What type of epithelial cyst resembles follicular epithelium?

Answer 11

Pilar/trichilemmal cyst.

Question 12

What type of epithelial cyst contains multiple skin appendages?

Answer 12

Dermoid cyst.

Question 13

What type of epithelial cyst resembles the duct of a sebaceous gland?

Answer 13

Steatocystoma.

Question 14

What is actinic keratosis (AK)?

Answer 14

Premalignant dysplasia of squamous epithelium before over malignancy.

Question 15

What causes actinic keratosis?

Answer 15

Chronic sun exposure.

Question 16

What is the appearance of actinic keratosis?

Answer 16

Small lesion with a variable appearance and rough ‘sandpaper’ texture that often appears as multiple lesions, sometimes can develop a ‘cutaneous horn’.

Question 17

What histological features are characteristic of actinic keratosis?

Answer 17

Cellular atypia in the basal layer, hyperkeratosis, parakeratosis, and elastosis.

Question 18

What is actinic keratosis a known precursor to?

Answer 18

Squamous cell carcinoma (SCC).

Question 19

What does full-thickness nuclear atypia of actinic keratosis indicate?

Answer 19

Progression to SCC in situ.

Question 20

How is actinic keratosis treated?

Answer 20

Curettage, freezing, or topical chemotherapies.

Question 21

What is the primary cause of squamous cell carcinoma?

Answer 21

DNA damage from UV exposure, suppression of Langerhans cells.

Question 22

What does full-thickness atypia confined by the basement membrane indicate?

Answer 22

In situ (Bowen’s disease).

Question 23

What are the morphological features of invasive SCC?

Answer 23

Marked hyperkeratosis, formation of keratin pearls, and intercellular bridging.

Question 24

What is the most common cancer in humans?

Answer 24

Basal cell carcinoma (BCC).

Question 25

What does basal cell carcinoma present as?

Answer 25

Pearly or waxy papules, often with telangiectasias, may have rolled borders and sometimes central ulceration.

Question 26

What are the histological presentations of basal cell carcinoma?

Answer 26

Tumor cells resembling the basal layer of the epidermis that form nodular nests infiltrating the dermis, peripheral palisading and stroma retraction.

Question 27

What is basal cell carcinoma associated with?

Answer 27

Mutations activating the hedgehog signaling pathway, often due to loss-of-function mutations in PTCH1.

Question 28

What syndrome is associated with inherited PTCH1 mutations and increased BCC incidence?

Answer 28

Gorlin syndrome.

Question 29

What are solar lentigines?

Answer 29

Benign lesions with localized increased melanocyte activity, common in older people and related to sun exposure.

Question 30

What is the appearance of solar lentigo?

Answer 30

Small, oval, tan-to-brown macules, with irregular borders, can occur on skin or mucous membranes.

Question 31

What growth pattern is seen in lentigo maligna melanoma?

Answer 31

Lentiginous growth pattern.

Question 32

What histological characteristic is seen in solar lentigo?

Answer 32

Linear (non-nested) melanocytic hyperplasia just above the basement membrane.

Question 33

What is a melanocytic nevus?

Answer 33

Any benign neoplasm of melanocytes, can be congenital or acquired.

Question 34

What is a junctional nevus?

Answer 34

Nests of melanocytes at the dermoepidermal junction presenting as flat and brown to black.

Question 35

What is a compound nevus?

Answer 35

Nests of melanocytes at the junction and within the dermis, presenting as slightly elevated and brown/light brown.

Question 36

What is an intradermal nevus?

Answer 36

Nests of melanocytes only within the dermis, presenting as dome-shaped, warty, or sessile.

Question 37

What type of nevus is common in children?

Answer 37

Spitz nevus.

Question 38

What are dysplastic nevi?

Answer 38

Potential precursors to melanoma, represents disordered proliferation of atypical melanocytes.

Question 39

What is the appearance of a dysplastic nevus?

Answer 39

>5mm flat or raised lesion with a pebbly/cracked surface, variable pigmentation, and irregular borders.

Question 40

What mutations are often carried by dysplastic nevi?

Answer 40

Activating mutations in BRAF or NRAS and loss-of-function mutations in CDKN2A.

Question 41

What are the histological characteristics of a dysplastic nevus?

Answer 41

Architectural disorder and cytologic atypia, bridging of rete ridges by nests, linear fibrosis around rete ridges.

Question 42

What is melanoma strongly linked to?

Answer 42

UV radiation-induced mutations.

Question 43

What does the ABCDE of melanoma stand for?

Answer 43

Asymmetry, Borders, Color, Diameter (>6mm), Evolution.

Question 44

What is the radial growth phase of melanoma?

Answer 44

Horizontal spread of melanoma along the dermoepidermal junction, can last months to years.

Question 45

What does early vertical growth indicate in melanoma?

Answer 45

Poor prognosis.

Question 46

What is the most common subtype of melanoma?

Answer 46

Superficial spreading (SSM).

Question 47

What subtype of melanoma has a very long radial phase?

Answer 47

Lentigo maligna melanoma (LMM).

Question 48

What subtype of melanoma has a rapid/undetectable radial phase?

Answer 48

Nodular melanoma.

Question 49

What is the most common subtype of melanoma in non-white patients?

Answer 49

Acral lentiginous melanoma.

Question 50

What subtype of melanoma affects the palms, soles, and under the nails?

Answer 50

Acral lentiginous melanoma.

Question 51

What subtype of melanoma has the worst prognosis typically?

Answer 51

Nodular melanoma.

Question 52

What is the most important local factor in determining prognosis of melanoma?

Answer 52

Breslow depth.

Question 53

What does TNM stand for in the staging system for melanoma?

Answer 53

Tumor thickness/ulceration (T), Node involvement (N), and Metastasis (M).