Dermatoscopic structures of non-melanocytic lesions Flashcards
Name this feature accentuated with the arrow, where are they commonly present?
These are Dots, they may be seen in pigmented BCCs and rarely Seborrhoeic Keratoses.
What are 4 dermatoscopic structures that are helpful in non-melanocytic lesions?
Leaf-like areas
Blue ovoid masses
Milia-like cysts
Fissures and comedo-like openings.
What dermatoscopic feature is seen in this lesion?
Structureless, Leaf-like areas. Grey, brown or blue structures unassociated with a pigment network (structureless). Seen on the edges of pigmented BCC, when they often have darker areas within them (blue ovoid masses).
What dermatoscopic feature is seen in this picture?
Blue Ovoid mass
Large discrete pigmented blue structures. Characteristic of BCC. When the structure has radial projections, they are called ‘spoke-wheel areas’. Often found within leaf-like/structureless areas. Blue blotches that are sometimes seen in melanoma are irregular, less well defined and appear out of focus.
What dermatoscopic feature is seen in this compound naevus?
Milia
Round white or yellow lesions due to intraepidermal keratin. Characteristically found within a seborrhoeic keratosis. They may also arise within dermal melanocytic naevi, BCC and melanoma.
What dermatoscopic feature can be seen in this Seb K?
Comedo-like openings are also called ‘crypts’. They are often associated with fissures (clefts). Characteristic of seborrhoeic keratoses, but may also be found in dermal naevi. Rarely found in melanoma.
What dermatoscopic feature can be seen in this Seb K?
A seborrhoeic keratosis may have a cerebriform or brain-like pattern. The pattern is composed of fissures and ridges mimicking the gyri and sulci of the brain.
What dermatoscopic feature can be seen in this naevus?
Finger-like Structures
A descriptive term for tan or dark-brown, fine parallel cord-like structures often seen in seborrhoeic keratoses and solar lentigo. Wider cords are called ‘fat fingers’. Fat fingers are also rarely seen in melanoma.
Describe 2 dermoscopic features of Haemangiomas or Angiomas
1-Widespread red-blue lacunes
2-Red-bluish-black homogeneous areas
Describe the border of this lesion and the white structures present. What can cause this lesion and what is the most important DDx?
- A distinct keratinised border or collarette (can also be present in Pyogenic Granuloma).
- White linear ‘rail lines’ are often featured.
- Amelanotic melanoma must be a differential diagnosis
Name this vascular lesion and describe 4 characteristics
Kaposi Sarcoma
1-Multicolour Rainbow Pattern
2-Bluish-red colour
3-Scaling
4-Small brown globules
NB: Rainbow pattern occasionally seen in melanoma and other skin lesions.
How can haemorrhage be distinguished from pigmentation due to melanin with dermoscopy?
Haemorrhage can be distinguished by the purple colour
Describe this lesion and it’s name
This is Talon Noir on the plantar surface
- It may appear to have a parallel ridge pattern of discolouration with peripheral reddish-black globules.
- Talon noir is also called ‘black heel’ or calcaneal petechiae, talon noir is considered to be induced by trauma.
What is an easily recognisable clinical characteristic of Dermatofibroma (aka Histiocytoma)?
What does dermoscopy of a dermatofibroma typically show?
Firm fibrous consistency and surface dimpling on compression
- A faint network or pseudonetwork surrounding a pale amorphous area.
- Sometimes the central white area has white lines and brown holes (negative network).
- Chrystalline structures, i.e. white shiny lines, are commonly seen on polarised dermoscopy of dermatofibroma.
NB: Rarely, a rainbow pattern can be observed.
Name and describe this uncommon type of dermatofibroma
Haemosiderotic dermatofibroma
- Composed of numerous small vessels, extravasated erythrocytes and intra- and extracellular haemosiderin deposits.
- Dermoscopy reveals multicomponent pattern with a central bluish or reddish homogeneous area in combination with white or yellowish structures and a peripheral delicate pigment network.
Give a clinical description of Neurofibroma and describe the sign that can help differentiate from the another skin condition it is often confused with.
Give a short Dermoscopic Description
Clinically Neurofibromas are soft to firm papules or nodules.
The buttonhole sign is helpful: you can push the lesion through a defect in the dermis and it bounces back when pressure is removed. This can differentiate it from a dermal naevus or skin tag.
Dermoscopically, Neurofibroma is a featureless nodule.
Define Lichenoid Keratosis
Describe it’s activity ata cellular level and how this gives the lesion its colour
Describe the pigment network in Lichenoid Keratosis
Lichenoid keratosis is an inflammatory reaction arising in a regressing existing solar lentigo or seborrhoeic keratosis.
- Localised destruction of melanocytes and free melanin in the dermis or melanin within melanophages. These appear as granular areas of grey dots. Grey dots can also be typically seen within melanoma.
- LK has no pigment network and there are usually amorphous areas with or without keratinous surface /or other features of seborrhoeic keratosis.
Describe Porokeratosis and it’s Dermatoscopic characteristics
Porokeratosis is distinguished by a cornoid lamella (horn-like thin layer) around the lesion. Sometimes there is prominent follicular plugging
Describe the dermatoscopic appearance of sebaceous hyperplasia and how the vascularity differs from BCC
Sebaceous hyperplasia is distinguished by pale yellow lobules around a central follicular opening. Telangiectasia is common but tends to be uniform, in contrast to the irregular arborising vessels seen in basal cell carcinoma.
Describe the different dermatoscopic features of viral warts, corns and a callus
Viral warts are keratinocytic lesions with a lobular structure, sometimes with a central thrombosed capillary within each lobule. The normal dermatoglyphics are interrupted. Some have a papilliform structure.
In contrast, a corn has a translucent central core, and a callus is hyperkeratotic without other distinguishing features.
Describe Epidermal Naevus and how it differs from a Seborrhoeic Keratosis
An Epidermal Naevus has fissures, crypts and milia.
-It resembles a seborrhoeic keratosis or viral wart, however differs because it is very uniform in appearance and appears within the first decade.
Describe the dermoscopy of the nipple
Breast tissue has a delicate uniform peripheral pigment network.
Describe this pigmentation pattern on normal areola
Delicate uniform peripheral pigment network
What is the main dermatoscopic feature of a cyst?
Central follicular opening
Describe the dermoscopic features of Clear Cell Acanthoma
Clear Cell Acanthoma is a benign epidermal tumour. There are multiple pinpoint or dotted vessels arranged in line like a string of pearls.
Describe the dermatoscopic features of Trichoepithelioma/Trichoadenoma
Multiple white clods of variable diameter ( milia like cysts )
Describe the vascular pattern in the below lesions with red scaly plaques:
1-Amelanotic melanoma:
2- Superficial basal cell carcinoma:
3-Squamous cell carcinoma in situ:
4-Psoriasis:
5-Lichen planus:
1-Atypical and polymorphous vascularity
2-Arborising telangiectasia, ulceration
3-Grouped glomerular vessels
4-Uniform distribution of red dots on a light pink homogeneous background
5-White Wickham’s striae, paucity of vessels
Describe the Dermoscopy (entodermoscopy) of Scabies, nits and cutaneous larvae migrans (hookworm)
Scabies-Identify a scabies mite and/or its faeces within its burrow (triangle shaped head)
Nits-Confirm the presence of nits gripping a hair shaft in pediculosis capitis
Cutaneous larvae migrans-2–3 mm-wide, snakelike tracks stretching 3–4 cm from the penetration site. These are slightly raised, flesh-coloured or pink
What 4 main characteristics do Seb Ks have?
1-Multiple milia-like cysts
2-Comedo-like openings
3-Light-brown fingerprint-like structures
4-Cerebriform pattern
