- Introduction to dermatoscopy
- Dermoscopic features
- Three-point checklist
- Dermoscopy of benign melanocytic lesions
- Dermoscopy of atypical naevi
- Dermoscopy of malignant melanoma
- Dermatoscopy of seborrhoeic keratosis
- Dermoscopy of basal cell carcinoma
- Dermatoscopy of squamous cell carcinoma
- Dermatoscopy of other non-melanocytic lesions
- First step algorithm
- Pattern analysis
- Other algorithms for melanocytic lesions
- The dermatoscopy report
- Melanocytic naevi: new classification
- Dermoscopy of the nail
- Dermatoscopic-histologic correlation
- Naevi with special features images
- Site-specific naevus images
- Unclassifiable naevus images
Developed in collaboration with the University of Auckland Goodfellow Unit in 2007.
Author: Hon A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand, 2008.혻혻
Images have been sourced from the following:
- Hon Assoc Prof Amanda Oakley
- The Department of Dermatology, Waikato Hospital
- MoleMap New Zealand (with permission)
- Dr Richard Williamson and coworkers (as indicated in dermatoscopic-histology page*)
Dermoscopy of squamous cell carcinomaNext Previous
- Describe dermoscopic features of pigmented and non-pigmented superficial and invasive squamous cell malignancy
There are specific and diagnostic features that enable confident diagnosis of pigmented and non-pigmented actinic keratosis and squamous cell carcinoma in situ. Invasive squamous cell carcinoma can be difficult to diagnose by dermoscopy alone.
Hand-held dermoscopy can be useful to distinguish squamous scaly, eroded flat or infiltrated and non-pigmented lesions from basal cell carcinoma. It can be more difficult for the teledermoscopist, who is unable to palpate the lesion.
Dermoscopy of actinic keratoses
Actinic (solar) keratoses may be pigmented or non-pigmented and the dermoscopic diagnosis is made when the strawberry pattern is present. This refers to a erythematous pseudonetwork on facial skin, in which there are prominent yellowish hair follicles surrounded by a white halo.They may also look like a target. Pigmentation may be due to grey or brown dots and globules, or to a broken-up pseudonetwork, resembling lentigo maligna. Short curved red blood vessels may be prominent. Rosettes, i.e. groups of 4 white shiny follicular perifollicular spots, are a feature of sun damaged skin on polarised dermoscopy.
On non-facial sites, actinic keratoses present with uniform pink or tan-coloured background and prominent keratin (white or yellow scale).
The main features of actinic keratosis are:
- erythematous pseudonetwork
- surface scale
- linear-wavy vessels
- follicular openings (yellow ovoid)
- globular structures with a white halo (white circles).
Dermoscopy of Bowen's disease
Dermoscopy can be helpful for diagnosing pigmented Bowen's disease (squamous cell carcinoma in situ), which presents as an irregular skin-coloured, pink or brown scaly plaque. Irregular clusters of so-called ?쁤lomerular vessels??(coiled vessels) and/or globular vessels (small red clods) are characteristic. They may be associated with a scaly surface, small brown globules, linear greyish dots and/or homogeneous pigmentation. Pigmented structures may be seen arranged in lines. White circles may be present, often in irregular clusters. There may be superficial erosion and crusting.
Non-pigmented Bowen's disease can be difficult to diagnose by dermoscopy. Compared with basal cell carcinoma, there is more scaling and the vascular pattern is glomerular/globular rather than arborising/branched. Background hue tends towards and orange shade of pink, whereas basal cell carcinoma tends to have more blue tone. Using polarisation, white shiny ?쁟rystalline??structures are uncommon but may form rosettes on facial skin (keratin around follicles). Compared to psoriasis, the lesion is asymmetrical and the structure irregular.
Dermoscopy of Bowen's disease: purple arrow shows glomerular vessels
Dermoscopy of invasive squamous cell carcinoma
Cutaneous invasive squamous cell carcinoma (SCC) is very variable in clinical appearance depending on the degree of differentiation and body site. It presents as a thickened plaque or nodule.
- Ulceration may or may not be prominent; severely ulcerated tumours are impossible to differentiate and may have no visible dermoscopic structures.
- Poorly differentiated tumours tend to be pinker compared to whitish well-differentiated lesions.
- Malignant tumours are destructive, resulting in loss of normal tissue compared to surrounding skin
- The hallmark of SCC is keratinisation, so white structureless areas are prevalent. In well differentiated tumours including keratoacanthoma, there may be a central area of superficial scale, crust or horn (white, yellowish or brown), surrounded by paler dull-white structureless zone. There may be
- Irregular groups of white perifollicular circles are typical of SCC.
- Blood spots are common
- Blood vessels are variable, with irregular round or coiled, looped, serpentine, branched or polymorphic morphology. Greater variation in vasculature is associated with less differentiation histopathologically.
Look for white circles in actinic keratoses, squamous cell carcinoma in situ and invasive squamous cell carcinoma.