Dermoscopy of atypical lesions

Question 1

Name the possible clinical characteristics in an ‘atypical’ or ‘dysplastic’ naevi. How many are required to make it dysplastic/atypical.

Answer 1

Diameter >5 mm

Ill-defined borders

Irregular margin

Varying shades in the lesion

Papular and macular components

*3 clinical characteristics are required.

Question 2

1-What are the best clues to indicate hystological atypia in dysplastic/atypical naevis?

2- What are the 6 possible structures in atypical naevi?

3-What morphological feature also indicates atypical naevus?

Answer 2

1-Clues appear to be related to structural features and pigment distribution. Frequently a patient with multiple atypical naevi has a predominance of one type.

2-Reticular

Globular

Homogeneous

Reticular/homogeneous

Globular/homogeneous

Reticular/globular

NB: Presence of all three types of structure is very suggestive of melanoma. It has also been shown that naevi showing complex dermoscopic pattern are more prevalent in patients who develop melanoma, i.e., naevi in which there are network, globules +/- structureless areas.

3-Combined macular and papular components are common features of atypical naevi.

Question 3

Name the lesion and the structural pattern:

Answer 3

Atypical naevi

Globular & Reticular pattern

Question 4

Name the lesion and the structural pattern:

Answer 4

Atypical naevi

Globular & Homogenous pattern

Question 5

Name the lesion and the structural pattern:

Answer 5

Atypical naevi

Globular & Homogenous pattern

Question 6

Name the lesion and the structural pattern:

Answer 6

Atypical naevi

Reticular & Homogenous pattern

Question 7

Name the lesion and the structural pattern:

Answer 7

Atypical naevi

Reticular & Homogenous pattern

Question 8

Name the lesion and the structural pattern:

Answer 8

Atypical naevi

Homogenous pattern

Question 9

Name the lesion and the structural pattern:

Answer 9

Atypical naevi

Globular pattern

Question 10

Name the lesion and the structural pattern:

Answer 10

Atypical naevi

Reticular pattern

Question 11

Explain the distribution types of pigmentation (6):

Answer 11

1-Uniform

2-Central hypopigmented annular type

3-Eccentric hypopigmented type

4-Central hyperpigmented type (darker skin types)

5-Eccentric hyperpigmented type (‘Bolognia naevus’)

6-Multifocal hyper-/hypopigmented type

Question 12

Name this naevi and describe it’s distribution of pigmentation:

Answer 12

Atypical naevi

Asymmetrical pigmentation

Question 13

Name this naevi and describe it’s distribution of pigmentation:

Answer 13

Atypical naevi

Multifocal pigmentation

Question 14

Name this naevi and describe it’s distribution of pigmentation:

Answer 14

Atypical naevi

Multifocal pigmentation

Question 15

Name this naevi and describe it’s distribution of pigmentation:

Answer 15

Atypical naevi

Eccentric Hyerpigmentation

Question 16

Name this naevi and describe it’s distribution of pigmentation:

Answer 16

Atypical naevi

Eccentric Hyerpigmentation

Question 17

Name this naevi and describe it’s distribution of pigmentation:

Answer 17

Atypical naevi

Central Hyerpigmentation

Question 18

Name this naevi and describe it’s distribution of pigmentation:

Answer 18

Atypical naevi

Uniform Hypopigmentation

Question 19

Name this naevi and describe it’s distribution of pigmentation:

Answer 19

Atypical naevi

Central Hypopigmentation

Question 20

Describe the terms Compound naevus and Combined naevus:

Answer 20

• Compound naevus is a benign melanocytic naevus in which melanocytes are found in both the epidermis and dermis.
• Combined naevus is used when the dermal component is a deeply pigmented blue naevus.

Question 21

Apart from pattern structures and pigment distribution, what are 3 other dermatological features which may indicate atypical naevi?

Answer 21

1-Dermoscopic regression structures (white scar-like areas and grey peppering)

2-Irregular vascular pattern

3-Grey-blue areas

Question 22

Name this lesion and the prominent feature indicating it’s name?

Answer 22

Atypical naevus, due to grey-blue areas

Question 23

Name this lesion and the prominent feature indicating it’s name?

Answer 23

Atypical naevus, due to areas of regression

Question 24

Name this lesion and the prominent feature indicating it’s name?

Answer 24

Atypical naevus, due to the presence of irregular vascular pattern

Question 25

Name this lesion and the prominent feature indicating it’s name?

Answer 25

Atypical naevus, due to the presence of grey peppering (can indicate regression)

Question 26

Describe a Spitz Naevi and the several dermatological patterns that have been associated with it.

Answer 26

Spitz naevi present as evolving lesions and tend to be pink (classic) or black (pigmented or Reed type). They often arise in children and eventually involute. They may be clinically, dermoscopically and histologically difficult to distinguish from melanoma.

*Dermoscopic patterns described for Spitz naevi include:

Globular: central grey or bluish pigment surrounded by large peripheral globules

Starburst: central grey or bluish pigment surrounded by radiating peripheral streaks or globules

Reticular: superficial dark network

Homogeneous

Atypical: irregular blotches, globules and streaks

Question 27

Describe some changes seen in benign moles that are unrelated to malignancy:

Answer 27

• Naevi with peripheral globules may frequently be observed to expand and lose their globules over a period of months.
• Uniform darkening in colour may be observed after sun exposure.
• Naevi may darken during pregnancy.
• The number of milia-like cysts in dermal naevi may vary.
• Naevi fade and disappear slowly in many adults, particularly after the age of 50.
• Trauma may result in inflammation, scabbing and crusting, which resolves within a few weeks.
• Naevi may recur if inadequately excised e.g. by shave biopsy.

Question 28

Describe the changes seen in this melanocytic naevi and whether you think a biopsy is required.

Answer 28

Naevi with peripheral globules may frequently be observed to expand and lose their globules over a period of months.

Naevi fade and disappear slowly in many adults, particularly after the age of 50.

-Biopsy not required.

Question 29

Describe the changes seen in this melanocytic naevi and whether you think a biopsy is required.

Answer 29

Scab on a melanocytic naevi. Trauma may result in inflammation, scabbing and crusting, which resolves within a few weeks.

-Biopsy not required.

Question 30

Describe the changes seen in this melanocytic naevi and whether you think a biopsy is required.

Answer 30

Repigmentation in a scar. Naevi may recur if inadequately excised e.g. by shave biopsy.

-Biopsy not required.

Question 31

Describe the changes seen in this melanocytic naevi and whether you think a biopsy is required.

Answer 31

Uniform darkening in colour may be observed after sun exposure.

-Biopsy not required.

Question 32

Describe the changes seen in this melanocytic naevi and whether you think a biopsy is required.

Answer 32

The number of milia-like cysts in dermal naevi may vary.

Naevi fade and disappear slowly in many adults, particularly after the age of 50.

-Biopsy not required.

Question 33

Describe the changes seen in this melanocytic naevi and whether you think a biopsy is required.

Answer 33

Uniform darkening in colour may be observed after sun exposure.

Naevi may darken during pregnancy.

-Biopsy not required.

Question 34

Describe the changes seen in this melanocytic naevi and whether you think a biopsy is required.

Answer 34

Changing s_hape, size or structure of flat atypical naevi_ are more worrying. About 10 to 15% of these will prove to be melanoma. If changes are mild, it may be reasonable to review the dermoscopy in 3 months.

There should be a low threshold for excision in changing atypical naevi that are elevated, because of rapid growth and relatively poor prognosis of nodular melanoma.

-Biopsy IS required.

Question 35

Describe the changes seen in this melanocytic naevi and whether you think a biopsy is required.

Answer 35

Changing s_hape, size or structure of flat atypical naevi_ are more worrying. About 10 to 15% of these will prove to be melanoma. If changes are mild, it may be reasonable to review the dermoscopy in 3 months.

There should be a low threshold for excision in changing atypical naevi that are elevated, because of rapid growth and relatively poor prognosis of nodular melanoma.

-Biopsy IS required.

Question 36

Describe the changes seen in this melanocytic naevi and whether you think a biopsy is required.

Answer 36

Changing s_hape, size or structure of flat atypical naevi_ are more worrying. About 10 to 15% of these will prove to be melanoma. If changes are mild, it may be reasonable to review the dermoscopy in 3 months.

There should be a low threshold for excision in changing atypical naevi that are elevated, because of rapid growth and relatively poor prognosis of nodular melanoma.

-Biopsy IS required.

Question 37

Describe the changes seen in this melanocytic naevi and whether you think a biopsy is required.

Answer 37

Changing s_hape, size or structure of flat atypical naevi_ are more worrying. About 10 to 15% of these will prove to be melanoma. If changes are mild, it may be reasonable to review the dermoscopy in 3 months.

There should be a low threshold for excision in changing atypical naevi that are elevated, because of rapid growth and relatively poor prognosis of nodular melanoma.

-Biopsy IS required.

Question 38

Describe the changes seen in this melanocytic naevi and whether you think a biopsy is required.

Answer 38

Naevi appears to fade and disappear slowly. This occurs in many adults, particularly after the age of 50.

-Biopsy not required.