Evaluation of two histological classifications for actinic keratoses - PRO classification scored highest inter-rater reliability.

BACKGROUND: Actinic keratoses (AKs) can histologically be classified by the extent of atypical keratinocytes throughout the epidermis or their pattern of basal proliferation. Currently, no data on the inter-rater reliability of both scores is available. OBJECTIVE: To evaluate the inter-rater reliability of the two classification schemes; histological grade (AK I-III) and basal proliferation (PRO I-III). METHODS: Histological images of 54 AKs were classified by 21 independent dermatopathologists with regard to basal proliferation (PRO I-III), histological grade (AK I-III) and assumed risk of progression into invasive carcinoma. RESULTS: Overall, of the 54 AKs 16.7% (9/54) were classified as AK I, 66.7% (36/54) as AK II, and 16.7% (9/54) as AK III. With regards to basal growth pattern, 25.9% (14/54) were classified as PRO I, 42.6% (23/54) as PRO II, and 31.5% (17/54) as PRO III. We observed a highly significant inter-rater reliability for PRO-grading (P < 0.001) which was higher than for AK-grading (Kendall's W coefficient: AK = 0.488 vs. PRO = 0.793). We found substantial agreement for assumed progression risk for AKs with worsening basal proliferation (k = 0.759) compared to moderate agreement (k = 0.563) for different AK-gradings. CONCLUSIONS: Histological classification of basal growth pattern (PRO) showed higher inter-rater reliability compared to the established classification of atypical keratinocytes throughout epidermal layers. Moreover, experienced dermatopathologists considered basal proliferation to be more important in terms of progression risk than upwards directed growth patterns. It should be considered to classify AKs according to their basal proliferation pattern (PRO I-III).

Queratosis actínica conjuntival / Conjunctival actinic keratosis

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Histological intralesional heterogeneity of actinic keratoses relates to field cancerization.

BACKGROUND/OBJECTIVES: Histological heterogeneity within distinct actinic keratosis (AK) lesions has been described and might serve as an additional feature of AKs. We aimed to investigate and quantify the histological heterogeneity of AKs regarding different grading systems. METHODS AND MATERIAL: We assessed the histology of 3 mm biopsies of AK lesions located on the scalp or face. We documented basal proliferation (PRO I-III), histological grade (AK I-III) and determined the overall classification of each lesion. RESULTS: Of the 305 lesions included, 48 (15.7 %) lesions were classified as AK I, 152 (49.8 %) as AK II and 105 (34.4 %) as AK III. 33 AKs (10.8 %) showed no basal proliferation, 94 (30.8 %) were graded as PRO I, 99 (32.5 %) as PRO II and 79 (25.9 %) as PRO III. One histological grade and basal growth pattern per lesion was observed in 94 (30.8 %) and 104 (34.1 %) cases respectively, two grades in 170 (55.7 %) and 168 (55.1 %) cases, and three grades in 41 (13.4 %) and 33 (10.8 %) cases (Chi-squared test, p < 0.0001). CONCLUSIONS: By analogy with the clinical heterogeneity of field cancerization, AKs show a high histological grade heterogeneity even within small lesions. Variations in AK grading reflect the heterogeneity of the cancerization field and might serve as additional feature.

Actinic keratoses show variable histological basal growth patterns - a proposed classification adjustment.

BACKGROUND: Common histological classification schemes of actinic keratoses (AK) do not evaluate growth patterns at basal epidermal aspects of AK. Until now, the importance of basal epidermal growth patterns of AK has not been studied. OBJECTIVE: To investigate the extent of atypical keratinocytes throughout the epidermis and variation in basal growth patterns of AK. METHODS: AK lesions occurring on the head/face from patients seen in routine practice were assessed histologically. We determined histological grade (AK I-III), basal growth patterns of atypical keratinocytes (crowding, budding and papillary sprouting) and accompanying parameters. RESULTS: Of the 246 lesions included, 28.0% were histologically classified as AK I, 46.7% as AK II and 25.2% as AK III. Approximately 26.4% of the basal growth patterns were classified as crowding (pro I), 49.6% as budding (pro II), 17.9% as papillary sprouting (pro III) and 6.1% without basal directed growth. No significant correlation of the histological AK I-III grading and underlying growth patterns was observed (P = 0.4666). However, adnexal structure involvement (OR = 2.37; 95% CI 1.21-4.65), infiltration (OR = 2.53; 95% CI 1.31-4.90) and increased number of vessels (OR = 2.56; 95% CI 1.42-4.65) were independent positive predictive markers for pro II and pro III basal growth patterns. CONCLUSIONS: Basal growth patterns (pro I-III) in AK do not correlate with the established AK I-III histological grading system. Besides the degree of upward extension, varying degrees of downward extension exist. Histological classification should consider both, upwards and downward growth patterns when assessing AK.

A Novel Actinic Keratosis Field Assessment Scale for Grading Actinic Keratosis Disease Severity.

Actinic keratosis (AK) lesions are surrounded by field cancerization (areas of subclinical, non-visible sun damage). Existing AK grading tools rely on AK counts, which are not reproducible. An Actinic Keratosis Field Assessment Scale (AK-FAS) for grading the severity of AK/field was developed. Standardized photographs of patients representing the full range of AK severity were collected. Six investigators independently rated each photograph according to 3 criteria: AK area (total skin area affected by AK lesions), hyperkeratosis and sun damage. Inter-rater reproducibility was good for all 3 criteria. Validation of the AK-FAS showed good reproducibility for AK area and hyperkeratosis, even for dermatologists untrained on use of the scale. In conclusion, the AK-FAS is objective, easy to use and implement, and reproducible. It incorporates assessment of the entire field affected by AK instead of relying on lesion counts. Use of the AK-FAS may standardize AK diagnosis, making it relevant to routine clinical practice.

From actinic keratosis to squamous cell carcinoma: pathophysiology revisited.

The precursor of most cutaneous invasive squamous cell carcinomas (iSCCs) is intraepithelial UV-induced damage, known as field cancerization, which can eventually transform into actinic keratosis (AK). Although AK is the most common precursor of iSCC, many AKs will either persist in the same stage or regress, while only a few will progress into iSCC. Nevertheless, because the progression of individual AKs cannot be predicted, it has been proposed that all AKs, regardless of the grade, should be carefully monitored and appropriately treated in clinical practice. Modern imaging techniques such as dermatoscopy, reflectance confocal microscopy (RCM) and high-definition optical coherence tomography (HD-OCT) may have potential to monitor the evolution of actinic field damage. Dermatoscopy can be used to differentiate between AK, intraepidermal carcinoma (IEC) and SCC which may help clinicians to diagnose in situ or invasive lesions at an earlier stage. HD-OCT and RCM can be used to detect cellular and histological changes characteristic of subclinical lesions, allowing visualization of previously invisible lesions. As development of invasive AK directly from the cancer field cannot be ruled out, the ideal treatment should be able to eradicate AK lesions and reverse the underlying field cancerization.

Clinical forms of actinic keratosis and levels of dysplasia of the epidermis.

OBJECTIVE: Introduction: Actinic keratosis (AK) is precancerous skin lesion that occurs in the sun-exposedskin areas characterized by local intraepidermal dysplasia of different severity (KIN I, KIN II and KIN III). The aim of this research was to study distribution patterns and morphological features of AK histological types. PATIENTS AND METHODS: Materials and Methods: The study included skin biopsy material from 68 patients with different clinical forms of AK. The diagnosis of AK was histologically confirmed in 100% of cases. RESULTS: Results: There were 63.21% of men and 36.8% of women among all patients with AK. The average age of patients was 73.3 ± 8.3.The most common clinico-histological forms of actinic keratosis were typical (41.2%), hypertrophic (16.2%), atrophic (14.7%) and pigmentary (11.7%), bowenoid (8.8%), acantholytic (7.4%). Among the rate of epidermal dysplasia there diagnosed cases of KIN І (50%), KIN ІІ (36.8%) and KIN III (13.2%). CONCLUSION: Conclusions: It was found a direct correlation between KIN I and typical and pigment forms of AK, KIN II and hypertrophic and bowenoid forms of AK.

The many clinico-pathologic faces of actinic keratosis: an atlas.

Actinic keratoses (AKs) are intraepithelial neoplasms formed by atypical keratinocyte proliferation. Histopathologically, typical AKs are characterized by a slightly thickened epidermis, usually with irregular downward buds, orthokeratosis alternating with parakeratosis ('pink and blue') with loss of the underlying granular layer and a disarrangement of the epidermis with atypical keratinocytes at the basal layer. There are several histopathological variants of AK according to the different degrees of keratinocytic atypia, epidermal hyperplasia/atrophy, inflammation and pigmentation. Some authors consider AK an early in situ squamous cell carcinoma and propose a classification of AK based on the extent of atypical keratinocytes in the epidermis.

[Potentially malignant disorders of the oral mucosa: terminology and classification]. / Affections potentiellement malignes de la muqueuse buccale: nomenclature et classification.

The last WHO expert workgroup recommended abandoning the distinction between potentially malignant lesions and conditions. The term to use is "potentially malignant disorders". Leukoplakia is the most common of these disorders, while erythroplakia is rather rare. The diagnosis is still made by excluding other documented white or red lesions. Despite progress in molecular biology, no marker allows predicting malignant transformation. These lesions are treated surgically with or without dysplasia. It is unknown if this surgery can really prevent transformation into squamous cell carcinoma. The potential malignancy of oral lichen planus is still debated. The risk of malignant transformation is lower than that of leukoplakia. No treatment may prevent this. Other potentially malignant conditions such as oral submucous fibrosis, actinic cheilitis, lupus, and immunodeficiency are rare.

A pilot study to assess the efficacy of photodynamic therapy for Japanese patients with actinic keratosis in relation to lesion size and histological severity.

BACKGROUND/PURPOSE: Topical 5-aminolevulinic acid (ALA)-based photodynamic therapy (PDT) is effective for actinic keratosis (AK); few studies have examined Oriental patients. The aim of this study is to assess the efficacy of PDT for the treatment of Japanese AK patients classified by lesion size and histological severity. METHODS: Thirty patients with solitary AK lesions were divided into two groups according to diameter: a small lesion group (SL), diameter < or =10 mm and a larger lesion group (LL), diameter >10 mm, and histological severity: Group I (mild and moderate) and Group II (severe). After application of 20% ALA for 4 h, exposure to an excimer-dye laser at 630 nm was performed at a dose of 50 J/cm(2) three times at an interval of 7 days. Therapeutic effects were assessed and followed for 12 months. RESULTS: In all 10 SL patients, atypical cells disappeared after PDT and did not recur for 12 months. However, for the 20 LL patients, recurrence was seen in 2 of the 14 Group I patients, while 4 of 6 Group II patients showed residual tumor cells after the first PDT session. CONCLUSION: The present study demonstrated that ALA-PDT might be useful for treatment of Japanese AK. The therapeutic outcome might depend on the lesion size and the histopathological severity.

Actinic damage in histopathologically normal skin.

OBJECTIVE: To establish measures of sun damage in histopathologically normal skin. STUDY DESIGN: Biopsies were taken from the upper inner arm, representing skin with presumably minimum sun exposure, from skin of the forearm with no visible sun damage, from skin of the forearm with visible sun damage and from normal-appearing skin from the forearm of individuals who had sun exposure that had resulted in actinic keratosis (AK) lesions. In addition, a data set of nuclei from AKs was recorded. RESULTS: In histopathologically normal skin, monotonically increasing damage was observed in individuals with increased exposure to solar radiation. CONCLUSION: Karyometry can detect and statistically secure changes in skin due to solar exposure at a stage at which the skin is histopathologically determined to be normal.