Squamous cell carcinoma
Squamous cell carcinomaThis glossary term has not yet been described. (SCC) is the second most common cutaneous malignancy after Basal Cell Carcinoma with an increasing incidence worldwide. It usually arises on sun-exposed areas of the skinThis glossary term has not yet been described., such as scalp, faceThis glossary term has not yet been described., neck, forearms and dorsal hands.
Invasive SCC appears often clinically as papulonodular, plaque-like, papilomatous or exophytic.
DermoscopyDermoscopy is a non invasive diagnostic method. criteriaThis glossary term has not yet been described.
- Central mass of keratin: amorphous, yellow-white to light-brown areas without any recognizable structure
- Targetoid hair follicles: keratotic plugs within follicular openings of the skin, mostly over a white structureless areahomogenous pattern various diagnoses
- Ulceration: large irregularly shaped or roundish areas of dull red or red-brown structureless colorColor (American English) or colour (Commonwealth English) is the characteristic of human visual perception described through color categories, with names such as red, yellow, purple, or blue.
- Herpin vesselsThis glossary term has not yet been described.: vascular loops, usually surrounded by whitish halo
- Linear-irregular vessels (serpentine): linear or slightly curved, irregularly shaped, sized and distributed red structures
Other vascular patterns, such as dotted and glomerular (coiled) vessels may also be present. Combinations of these vascular morphologies result in the so-called polymorphous pattern.
Poorly differentiated SCCs are dermoscopically typified by a predominantly red color, resulting from the presence of bleeding and dense vascularity. On the other hand, white colored criteria (central mass of keratin, whitish halos and structureless whitish areas) are associated with well- or moderately differentiated variants.
Progression model of actinic keratosisActinic keratosis (also called solar keratosis and senile keratosis; abbreviated as AK) is a pre-cancerous patch of thick, scaly, or crusty skin. These growths are more common in fair-skinned people and those who are frequently in the sun. They usually form when skin gets damaged by ultraviolet (UV) radiation from the sun or indoor tanning beds. AKs are considered potentially pre-cancerous; left untreated, they may turn into a type of cancer called squamous cell carcinoma. Untreated lesions have up to a 20% risk of progression to squamous cell carcinoma, so treatment by a dermatologist is recommended. to squamous cell carcinoma
Invasive SCC often arises in association with actinic keratosis (AK). The progression model of AK to SCC suggests an initial transition from a red pseudonetworkA structureless pigment area interrupted by non-pigmented adnexal openings ("strawberry patternReddish pseudo-network (erythema and wavy fine vessels) around hair follicle openings which are accentuated with a white halo appearance") to an increasing neovascularization (development of clustered dotted/glomerular vesselsThis glossary term has not yet been described.). The follicles gradually miniaturize and disappear, whereas hairpin and linear-irregular vessels appear. Along with these vascular changes, a central mass of keratin forms and ulceration may occur.
Pigmented invasive squamous cell carcinoma
Pigmented invasive SCC is rare variant of SCC. Dermoscopically, it reveals a diffuse, homogeneous blue pigmentation with distinct, irregularly distributed, blue-gray granular structures. If ulcerated, dark brown to black crusts are visible. Due to the pigmentation, vessels are usually not seen.
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