Benign Melanocytic Neoplasms

Front 1

What causes the hyperpigmentation in ephelides (2)?

Back 1

1. Sun-induced melanogenesis

2. Transport of increased # of fully melanized melanosomes to keratinocytes

Front 2

What are differences between ephelides and lentigines (3)?

Back 2

1. Ephelides are lighter in color

2. Ephelides are confined to sun-exposed skin, while lentigines can appear anywhere

3. Ephelides are responsive to sun exposure, while lentigines do not change

Front 3

Describe the growth of cafe-au-lait macules

Back 3

Enlarge proportionately with overall body growth, then remain stable during adulthood

Front 4

Two conditions in which cafe-au-lait macules are part of the clinical presentation?

Back 4

1. Neurofibromatosis Type 1

2. McCune-Albright syndrome

Front 5

Which syndrome typically has large cafe-au-lait macules that are generally found midline?

Back 5

McCune-Albright syndrome

Front 6

What is a probable cause for the pathogenesis of Becker's melanosis?

Back 6

Increase in androgen receptors and heightened sensitivity to androgens

(onset during/after puberty, hypertrichosis, dermal thickening, acne, and hypertrophic sebaceous glands are associated with Becker's melanosis)

Front 7

What decade of life do Becker's nevi usually appear?

Back 7

2nd or 3rd decade of life

Front 8

Most common distribution of a Becker's nevus?

Back 8

Unilateral on an upper quadrant of the anterior or posterior chest + shoulder

Front 9

What genetic disease has solar lentigines as part of its clinical presentation?

Back 9

Xeroderma pigmentosum

Inability to repair damage from UV radiation leads to lots of solar lentigines, NMSCs, and melanomas

Front 10

Histopathologic differences in solar lentigines vs ephelis?

Back 10

Rete ridges are more club-shaped and elongated

Solar elastosis is usually present

Front 11

Name for a brown macule with early age of onset and little or no relationship to sun exposure?

Back 11

Lentigo simplex

Front 12

Melanosis/lentigines in which location would give you worry for melanoma?

Back 12

Conjunctiva; primary acquired melanosis is a precursor lesion of melanoma in this area

Front 13

Clinical presentation of LEOPARD syndrome (acronym)?

Back 13

1. Lentigines

2. Electrocardiographic conduction defects

3. Ocular hypertelorism

4. Pulmonary stenosis

5. Abnormalities of genitalia

6. Retardation of growth

7. Deafness

Front 14

Clinical presentation of Carney complex?

Back 14

Multiple lentigines + multiple neoplasias

(myxomas of skin/heart/breast, schwannomas, blue nevi, pituitary adenoma, sertoli tumors)

Front 15

Clinical presentation of Peutz-Jeghers?

Back 15

Mucocutaneous lentigines + intestinal polyposis

Front 16

Primary body location for dermal melanocytosis?

Back 16

Lumbosacral region

Front 17

Which ethnicity has the highest prevalence of dermal melanocytosis?

Back 17

Asians

Front 18

In Mongolian spots, where are the melanocytes usually found?

Back 18

Middle to lower dermis

Front 19

What phenomenon explains the blue color in dermal melanocytosis?

Back 19

Tyndall phenomenon

I.e. decreased reflectance of light in lower-wavelength region (roygbiv) compared with surrounding skin; blue and violet wavelengths are reflected

Front 20

Unilateral bluish macules with confluence to form an irregularly demarcated and mottled patch on the face?

Back 20

Nevus of Ota

Usually V1/V2 distribution, can involve sclera, sometimes bilateral

Front 21

What is the common facial distribution for Nevus of Ota?

Back 21

V1 and V2 distribution

Front 22

Most common demographic for Nevus of Ota?

Back 22

Asians and blacks, females (80%)

Front 23

What can be said about melanomas that arise from Nevus of Ota?

Back 23

Typically present as subcutaneous nodules; do not adhere for the ABCD rules of melanoma

Can also have primary melanoma of eye structures (choroid, orbit, iris, meninges) if sclera is involved

Front 24

Most common distribution for Nevus of Ito?

Back 24

Posterior supraclavicular, along lateral cutaneous brachial nerves (scapular, deltoid, supraclavicular)

Front 25

Which lasers are effective in treating Nevus of Ota/Ito (3)?

Back 25

Q-switched ruby

Alexandrite

Nd:YAG

Front 26

What 3 body locations are the most common for blue nevi?

Back 26

1. Scalp

2. Sacral region

3. Dorsal aspects of distal extremities

Front 27

Well-circumscribed, dome-shaped blue-gray papule on the face, hands, or feet?

Back 27

Blue nevus

Front 28

Histologic appearance of blue nevi?

Back 28

Heavily pigmented, spindle-shaped melanocytes in dense collections within the dermis

Long axis of melanocytes is parallel with the epidermis

Front 29

Large (1-3 cm) firm blue plaque on the buttocks, sacral region, or scalp?

Back 29

Cellular blue nevi

Front 30

Histologically, what to cellular blue nevi have that common blue nevi don't?

Back 30

Plump elongated melanocytes devoid of melanin pigment

Front 31

What are "good" features of benign melanocytic nevi?

Back 31

1. Well-circumscribed, regular well-defined borders

2. Round/ovoid

3. Symmetric

4. Size 2-6 mm

5. Contain course and dark hairs

Front 32

Back 32

Junctional melanocytic nevus

Dark brown macule with uniform pigment network that thins out towards periphery

Front 33

Back 33

Compound nevus

Light to medium brown papule with multiple round/ovoid globules forming a cobblestone pattern

Front 34

Back 34

Intradermal nevus

Pink to light brown papule with focal globular areas, whitish structureless areas, and fine comma vessels

Front 35

What bullous disorder can have large, asymmetric melanocytic nevi associated with it?

Back 35

Epidermolysis bullosa (particularly the AR inherited forms such as simplex)

Front 36

What is the most common dermoscopic pattern in acral melanocytic nevi?

Back 36

Parallel furrow

Front 37

What mutation is often found in common acquired melanocytic nevi?

Back 37

Somatic mutations in BRAF

Front 38

Clinical presentation of Spitz nevi?

Back 38

Well-circumscribed dome-shaped papules or nodules that are pink to tan to dark brown; telangiectasias are a frequent finding

Front 39

What type of nevus characteristically has a "starburst" pattern on dermoscopy?

Back 39

Reed nevus (likely a variant of Spitz nevus)

Front 40

What are the histologic characteristics of Spitz nevi?

Back 40

1. Nests of large spindle and epithelioid cells vertically oriented along the rete ("raining-down pattern", inverted wedge-shape pattern)

2. Sharply defined laterally

3. Orderly infiltration of dermal collagen by these cell nests with "maturation" (gradual diminution of nuclear and cellular sizes)

4. Occasional bizarre cytologic features (necrotic bodies, mitotic figures)

Front 41

Most common location to find Spitz nevi in adults?

Back 41

Head (face) and neck, also scalp

Front 42

Why do some dermatologists worry about Spitz nevi?

Back 42

- share histologic overlap with melanoma (large spindle and epithelioid cells)

- recurrence is sometimes noted

Front 43

Most common location for Reed nevus?

Back 43

Extremities; particularly the thigh

Front 44

Characteristic histology of Reed nevus?

Back 44

Fascicles of uniform, slender spindle cells that are closely aggregated

Front 45

Most common diagnosis of a recently developed or changing small, well-circumscribed black lesion on the thigh of a young woman?

Back 45

Reed nevus

Front 46

Another name for Clark's nevus?

Back 46

Atypical (dysplastic) melanocytic nevus

Front 47

For suspected atypical nevi, what margins should you use for the initial biopsy?

Back 47

2mm margins; deep shave (i.e. saucerization) is preferred over punch

Front 48

What are the cut-off sizes for small, medium, and large congenital melanocytic nevi?

Back 48

Small is < 1.5 cm

Medium is b/w 1.5 and 19.9 cm

Large is > 20 cm (or > 9cm on scalp for adults, > 6 cm on trunk for newborns)

Front 49

What mutation is commonly seen in congenital melanocytic nevi?

Back 49

NRAS mutation

Front 50

What is a complication seen in congenital melanocytic nevi, particularly in cases with multiple satellite-like lesions, a large CMN, or posterior axial location?

Back 50

Neurocutaneous melanosis

Perform an MRI for evaluation in suspected individuals

Front 51

How does neurocutaneous melanosis typically present?

Back 51

Signs and symptoms of increased intracranial pressure

(often due to hydrocephalus, mass effect)

Front 52

What is seen on MRI for neurocutaneous melanosis (3)?

Back 52

1. Post-gadolinium enhancing mass

2. Post-gadolinium enhancing diffuse thickening of the leptomeninges

3. Focal areas of increased signal on T1

Front 53

Melanoma risk in congenital melanocytic nevi is related to what?

Back 53

Size of the lesion

Small and medium-sized CMNs are not associated with significantly increased risk; giant CMNs have substantial melanoma risk

Front 54

Histological difference between congenital melanocytic nevi and common acquired nevi?

Back 54

CMNs typically have deeper infiltration (lower reticular dermis, subq fat, surrounding blood vessels, within adnexal structures)

Front 55

Tan macule or patch with darker speckles within?

Back 55

Nevus spilus

Front 56

Nevus spilus can be seen in which conditions (2)?

Back 56

1. Phakomatosis pigmentovascularis types III and IV

2. Phakomatosis pigmentokeratotica