Dermatopathology I

Question 1

Vitiligo:

Answer 1

Chronic depigmenting condition from complete loss of epidermal melanocytes.

Question 2

Vitiligo cause:

Answer 2

Autoantibody against melanin-concentrating hormone receptor 1 in serum.

Question 3

Vitiligo repigmentation:

Answer 3

Begins around hair follicles that look like freckles and become confluent.

Question 4

Ephelis (4):

Answer 4

Freckle

• Basal layer hyperpigmentation
• Appear after sun exposure in lightly pigmented kids
• Darken with sun exposure
• No risk of malignancy

Question 5

Lentigo (3):

Answer 5

• Small circumscribed brown macular lesions
• Hyperpigmentation of cells just above the basement membrane
• Do not darken with sun exposure

Question 6

Melanocytic nevi gross features (5):

Answer 6

• Tan to brown
• Uniformly pigmented
• Small
• Flat to elevated
• Well-defined, rounded borders

Question 7

Melanocytic nevi histological features (5):

Answer 7

• Sharply defined
• Well nested at the dermal-epidermal junction
• Melanocytes mature as they descend in dermis
• No deep mitoses
• No deep pigment in melanocytic nests

Question 8

Location of melanocytic nests in junctional melanocytic nevus:

Answer 8

Tips and sides of rete.

Question 9

Compound melanocytic nevus histologic features:

Answer 9

Histologic features of junctional nevus + nests and cords of nevus cells in underlying dermis.

Question 10

Dermal melanocytic nevus histologic feature:

Answer 10

Epidermal nests are lost completely

Question 11

Spitz Nevus (6):

Answer 11

• Composed of spindle and/or epithelioid cells
• Dyskeratotic melanocytes
• Sharply defined laterally
• Line symmetry from left to right
• Clefts separating nests from keratinocytes
• Deep red color

Question 12

Kamino bodies:

Answer 12

Dyskeratotic melanocytes

- Eosinophilic bodies along dermal-epidermal junction

Question 13

Dysplastic (atypical) melanocytic nevus (3):

Answer 13

• Commonly large, oval and multiple
• Irregular pigment common
• Fading border/fried egg appearance

Question 14

Dysplastic melanocytic nevus histologic features (3):

Answer 14

• Horizontally oriented nests with bridging of adjacent rete
• Nests are at the tips and sides of rete
• Cytologic atypia: hyperchromatic, enlarged nuclei

Question 15

Number 1 cause of skin cancer deaths worldwide:

Answer 15

Melanoma

Question 16

Melanoma:

Answer 16

Malignancy of pigment-producing cells (melanocytes)

Question 17

Melanoma stage determination:

Answer 17

Vertical phase depth.

Question 18

ABCDE of melanoma:

Answer 18

A: Asymmetry
B: Border irregularity
C: Color variation
D: Diameter > 6mm
E: Evolving

Question 19

Radial growth phase (2):

Answer 19

Melanoma-in-situ

• Horizontal spread of melanoma cells within the epidermis and superficial dermis
• Tumor cell slack the ability to metastasize

Question 20

Vertical growth phase (4):

Answer 20

• Tumor cells invade downward into deeper dermal layers as a mass
• Cells with metastatic potential emerge
• Invading cells do not mature
• Grossly, a nodule appears

Question 21

Most common melanoma subtype:

Answer 21

Superficial spreading

Question 22

Superficial spreading melanoma is usually found on:

Answer 22

Sun-exposed skin, typically on backs of men and lower legs of women, but any age, any place.

Question 23

Superficial spreading malignant melanoma histologic features (5):

Answer 23

• Buckshot scatter of atypical melanocytes within the epidermis
• Typically not symmetrical
• Typically fails to mature from top to bottom
• Deep mitoses may be present
• Cytologic atypia

Question 24

Lentigo maligna melanoma (4):

Answer 24

• Indolent, slow growing lesion
• Typically on the face of old men
• Long radial growth phase, 10-50 years
• Starts as a tan-brown macule and gradually enlarges developing a darker, asymmetric foci

Question 25

Lentigo maligna histologic features (3):

Answer 25

Melanoma-in-situ - Poorly nested and confluent melanocytes at the dermal epidermal junction - Adnexal extension - Heavily sun damaged skin

Question 26

Acral lentiginous melanoma (2):

Answer 26

- Most common melanoma in African Americans and Asians | - Palms, soles, beneath nail plate

Question 27

Nodular melanoma histologic features (4):

Answer 27

- Vertical growth phase melanoma - No apparent radial growth phase - Dermal growth occurs in isolation or in association with an epidermal component - Mitoses are frequent and often atypical

Question 28

Melanoma prognostic factors (5):

Answer 28

- Tumor thickness - Mitotic rate - Ulceration - Lymph node involvement - Distant metastases

Question 29

Most common benign tumor in older individuals:

Answer 29

Seborrheic keratosis

Question 30

Seborrheic keratosis (4):

Answer 30

- Begin as light brown flat macules - Develop velvety or waxy to finely verrucous surface - Color may vary from pink to dark brown or black - Appear stuck on and crumble with scraping

Question 31

Dermatosis papulosa nigra (3):

Answer 31

- Brown to black, smooth, dome-shaped papules - Most often seen in African Americans - Sub-type of seborrheic keratosis

Question 32

Acanthosis nigrans (5):

Answer 32

- Hyperpigmentation is first sign - Hyperplasia of stratum spinosum makes skin thick and velvety - Usually found in folds of the neck, axilla and groin - Associated with endocrine abnormalites - Associated with visceral malignancy in middle-aged and older

Question 33

Epidermal (inclusion) cyst histologic features:

Answer 33

Cyst wall resembles normal epidermis, filled with strands of keratin

Question 34

Earliest identifiable lesion that can develop into squamous cell carcinoma (SCC):

Answer 34

Actinic keratosis

Question 35

Actinic keratosis risk factors (3):

Answer 35

- Years of sun exposure - Fair skin - Immunosuppression

Question 36

Actinic keratosis appearance (3):

Answer 36

- Initially may be hard to see but will have areas of rough or "gritty" skin - Discrete, scaly, feels like "broken glass" surface lesion - Develop into poorly-demarcated, slightly erythematous papule or plaque with scale

Question 37

Most common cancer in the US:

Answer 37

Nonmelanoma Skin Cancer (NMSC)

Question 38

Majority of NMSC:

Answer 38

Basal cell carcinomas (BCC)

Question 39

Bowen disease:

Answer 39

Subtype of SCC-in-situ characterized by a sharply demarcated pink plaque and can arise on non-sun-exposed skin.

Question 40

Erythroplasia of Queyrat:

Answer 40

Bowen disease of the glans penis, which manifests as one or more velvety red plaques

Question 41

Invasive SCC (2):

Answer 41

- Raised, firm, pink-to-flesh colored keratotic papule or plaque arising on sun-exposed skin - Surface changes: scaling, ulceration, crusting, or cutaneous horn

Question 42

Keratoacanthoma (5):

Answer 42

- Benign epithelial tumor that may progress to SCC - Appear suddenly on actinically-damaged skin - Spontaneously regress after a few months - Red to flesh colored dome-shaped papule with a central crater filled with keratinous plug - Treat the same as SCC

Question 43

Basal cell carcinoma (BCC) (3):

Answer 43

- Pluripotential cells in the basal layer of the epidermis or follicular structures - Can cause local destruction and disfigurement - Slow grown and rarely metastasizes

Question 44

Nodular BCC (7):

Answer 44

- Face most common site - Waxy papules with central depression - Pearly appearance - Erosion, ulceration or crusting - Bleeding with minor trauma - Rolled border - Telangiectasias over the surface

Question 45

Superficial BCC (4):

Answer 45

- Trunk is most common site - Slight scaly papule or plaque - Light red color - Atrophic center with fine translucent micropapules on rim