Pigmented Lesions: Clinical Cases

Question 1

Types of benign melanocytic lesions?

Answer 1

Ephilides (macules)

Lentigines (macules)

Naevi/moles (macules/plaques/papules/nodules)

Question 2

Describe naevi

Answer 2

AKA moles; increased basal melanocytes (nests) with down-growths at the DEJ

Question 3

What is this called?

IMAGE1

Answer 3

Benign labial lentigo

Question 4

How do congenital melanocytic naevi differ from those that are acquired?

Answer 4

Larger and slightly raised

Become more rugose and elevated as the child grows older

Increased risk of melanoma in large naevi

Question 5

How to treat congenital melanocytic naevi?

Answer 5

Excision OR yearly follow-up

Question 6

How does melanoma risk increase with no. of atypical naevi?

Answer 6

Relative risk of melanoma increases with no. of atypical naevi

If there are 2, this is 2x higher risk
If there are 6, this is 6x high risk

Question 7

What is a naevus spillus?

Answer 7

Speckled lentiginous naevi;

dark spots on a flat tan background

Question 8

Dermoscopy of a MM reveals?

Answer 8

Atypical pigment network, black dots, irregular streaks

Focally, a blue-whitish veil and a white regression zone with a hairpin vessels

Question 9

What is the most prognostic factor in melanoma?

Answer 9

Breslow thickness

Question 10

5 year survival with relation to Breslow thickness?

Answer 10

Melanoma in situ 100%

3.0mm 40%

Question 11

Describe a superficial spreading melanoma

Answer 11

Most common sub-type, affects young middle-aged adults; usually trunk of men or legs of women

Macule with irregular border and colour which may have been increasing in size for years (slow horizontal growth phase) before developing a nodule (rapid vertical growth phase)

Question 12

Describe nodular melanoma

Answer 12

Occurs at any body site and usually in older patients

Blue-black or red-skin coloured nodule which may be ulcerated or bleeding and has usually developed rapidly over preceding months
Unlike nodules developing in superficial spreading melanoma, nodular melanomas do not have any significant surrounding macular pigmentation; they have an aggressive growth pattern (vertical, at outset)

Question 13

Describe lentigo maligna melanoma

Answer 13

Invasive melanoma developing within a lentigo maligna; confined to the tissue of origin, the epidermis, hence it is often reported as ‘in situ’ melanoma

Occurs in sun damaged skin, so it is often on the face or scalp

Question 14

What is Hutchinson’s sign?

Answer 14

Subungual melanoma sign

Characterized by extension of brown/black pigment from the nail bed, matrix, and nail plate to the adjacent cuticle and proximal or lateral nail folds

Question 15

What is amelanotic melanoma?

Answer 15

Absent or minimal visible pigment; so, pink or light-coloured and can difficult to identify as a melanoma

Question 16

Describe seborrheic keratoses

Answer 16

Harmless warty (looks stuck on), brown/black lesions, that appears during adult life as a common sign of skin aging

Mat detach spontaneously or in part

Question 17

Treatment of seborrheic keratoses?

Answer 17

Reassurance

Freeze

Curette

Shave

Question 18

What is a dermatofibroma?

Answer 18

Benign fibrous nodule that most often arises on the skin of the lower legs; some can be due to insect bites

Dermal, brown/grey, firm nodules

Question 19

Treatment of dermatofibromas?

Answer 19

Reassurance or excise

Question 20

What is a talon noir (subcorneal haematoma)?

Answer 20

“Black heel” is induced by trauma

Question 21

Treatment of melanoma?

Answer 21

Surgery

1 cm lateral margin for every 1 mm depth invasion (no benefit > 3 cm)

Sentinel lymph node biopsy – gives further prognostic information

Regional nodal basin dissection – if clinically palpable nodes

Other staging investigations, e.g: CT scan