Bowen's Disease
Author: Dr Olivia Wooler
Chief Editor: Dr Daniel Keith
Bowen’s disease is also known as squamous cell carcinoma in situ. Histologically, it is characterised by full-thickness dysplasia of the epidermis, with atypical keratinocytes that have not yet breached the basement membrane to become invasive SCC. It is therefore considered an early form of skin cancer, with the potential to progress to SCC if left untreated.
The main cause of Bowen’s disease is UV radiation, and it most commonly affects areas of the body exposed to the sun, such as the head, neck and extremities. It primarily affects individuals over the age of 60 with Fitzpatrick type 1 or 2 skin. It typically presents as an asymptomatic, slow-growing, solitary lesion, although multiple can occur.
Macroscopic Appearance
Macroscopically, Bowen’s disease appears as a well-demarcated, erythematous patch or plaque with a scaly surface. Lesions vary in size, ranging from a few millimetres to several centimetres.
Example 1
Macroscopic appearance of Bowen’s disease, demonstrating a well-demarcated, scaly patch.
Example 2
Another example of Bowen’s disease demonstrating an irregular scaly patch.
Dermoscopic Appearance
Features:
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Clusters of highly vascular areas, with glomerular and dotted vessels
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Hyperkeratosis, seen as discrete yellow or white opaque scales
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Background erythema
The two types of vascular pattern seen in Bowen’s Disease
A: Dotted/globular vessels - small red dots
B: Glomerular/coiled vessels - these are larger than dotted vessels with a convoluted morphology that resembles the glomerular apparatus of the kidney
Both patterns of are often seen in the same lesion
Dermoscopic Appearance of example 1 (Unannotated)
Dermoscopic Appearance of Example 1 (Annotated)
Blood spots can be seen on the keratin in this example
Dermoscopic Appearance of Example 2 (Unannotated)
Dermoscopic Appearance of Example 2 (Annotated)
Transformation into SCC
It is estimated that 3-5% of Bowen’s disease transform into invasive SCC. For this reason, it should be treated, or at least monitored. Clinical features suggestive of transformation include rapid growth, induration, ulceration, and bleeding.
Dermoscopically, the following features suggest transformation:
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A polymorphous vascular pattern, with looped, hairpin and linear (serpentine) vessels
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White structureless areas, corresponding to keratin masses or keratotic plugs within follicular openings
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Ulceration, indicated by red or brown structureless areas
The following images are an example of Bowen’s disease with features suggestive of transformation into invasive SCC.
Bowen’s transformed into SCC
Macroscopic image, demonstrating an erythematous, scaly, ulcerated lesion
Dermoscopic appearance of the lesion (unannotated)
Dermoscopic appearance of the lesion (annotated)
The clusters of the glomerular vessels at the periphery of the image correspond with Bowen’s disease, however looped (blue diamond), hairpin (green diamond) and linear (orange diamond) vessels can be seen more centrally, suggesting possible transformation into SCC.
White areas (yellow stars) may correspond with the hyperkeratosis seen in Bowen’s disease, but could indicate transformation into SCC.