Actinic Keratoses: Clinical Review

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Questions and Answers

Who first described actinic keratoses in 1826?

Jansen

Pinkus

Freudenthal

Dubreuilh (correct)

What term was later proposed by Freudenthal for actinic keratoses?

Keratoma senilis (correct)

Keratoma maligna

Actinic lesions

Solar keratosis

According to some authors, how should actinic keratoses be classified due to DNA modifications in keratinocytes?

As benign lesions

As in situ neoplasms (correct)

As acute inflammatory lesions

As benign tumors

What is one of the characteristics of actinic keratoses mentioned in relation to malignancy?

Cytological changes Signup and view all the answers

Which of the following is NOT a synonym for actinic keratoses?

Keratoma malignantum Signup and view all the answers

What are actinic keratoses primarily characterized by?

Dysplastic proliferations of keratinocytes Signup and view all the answers

Where do actinic keratoses typically occur?

On photoexposed areas Signup and view all the answers

What factor is the primary cause of actinic keratoses?

Ultraviolet radiation Signup and view all the answers

What is the risk associated with untreated actinic keratoses?

Transformation into squamous cell carcinoma Signup and view all the answers

How can actinic keratoses at initial stages be identified most effectively?

By palpation rather than visual inspection Signup and view all the answers

What percentage range reflects the prevalence of actinic keratoses in Caucasian individuals above 40 years?

11% to 60% Signup and view all the answers

Which therapeutic modality is NOT commonly used for actinic keratoses?

Radiation therapy Signup and view all the answers

In the diagnosis of actinic keratoses, what may sometimes be necessary besides clinical examination?

Histopathological analysis Signup and view all the answers

What common dermatological diagnosis represents the fourth most frequent in Brazil?

Actinic keratoses Signup and view all the answers

What molecular alteration is commonly associated with both actinic keratoses and spinocellular carcinomas?

Mutations in the p53 protein Signup and view all the answers

At what age group do actinic keratoses represent the main reason for dermatological consultation in Brazil?

Over 65 years Signup and view all the answers

In the study conducted in Curitiba, what was the prevalence of actinic keratosis in women?

60.79% Signup and view all the answers

What is the prevalence of actinic keratoses among individuals in Northern Brazil as mentioned in the study?

2.89% Signup and view all the answers

Which term has been proposed as a replacement for actinic keratosis?

Keratinocytic intraepidermal neoplasia Signup and view all the answers

What percentage of actinic keratosis prevalence was observed in Japanese descendants living in Bauru?

13.4% Signup and view all the answers

The study indicates that actinic keratosis prevalence increases with which patient characteristic?

Age Signup and view all the answers

Study Notes

Actinic Keratoses Overview

Actinic keratoses (AK) are dysplastic proliferations of keratinocytes with a potential for malignant transformation.
Clinically manifest as macules, papules, or hyperkeratotic plaques often on sun-exposed areas with an erythematous background.
Initial identification may require palpation, as lesions can be subtle in early stages.
Possible pigmentation and variable infiltration; multiple lesions signify field cancerization.
Prevalence among Caucasians over 40 years ranges from 11% to 60%.

Pathogenesis and Risk Factors

Primary risk factor is ultraviolet (UV) radiation exposure; individual genetic factors also contribute.
Diagnosis often involves both clinical evaluation and dermoscopy; histopathological analysis may be necessary in certain cases.
Major concern is the transformation risk into squamous cell carcinoma (SCC).

Treatment Options

Therapeutic approaches include topical medications, ablative therapies, and surgical options.
Treatment must be individualized based on patient factors.

Historical Context

The condition was first described by Dubreuilh in 1826, with subsequent nomenclature changes reflecting evolving understanding.
Currently considered pre-neoplastic; some authors propose viewing them as in situ neoplasms due to clonal DNA modifications.

Epidemiology in Brazil

Actinic keratoses are the fourth most common dermatological diagnosis in Brazil.
Represent the leading reason for dermatological consultations in individuals over 65 years (17.2%).
In Southern Brazil, constitute 7.4% of diagnoses, lower in the North region at 2.89%.
A study in Curitiba reports a 60.79% prevalence rate in women and 30.9% in men, with a mean age of 59.8 years.
High prevalence noted among Brazilian Japanese descendants with a rate of 13.4%, mean age of 68.9 years, surpassing similar demographic studies in Japan.

Cellular and Molecular Characteristics

Histological features include loss of polarity, nuclear pleomorphism, disorganized maturation, and increased mitotic activity.
Similar p53 mutations found in keratinocytes of AK and SCC, reinforcing the potential malignancy of AK.

Evolutionary Perspective

No clear threshold exists between actinic keratoses and thin SCC; considered part of the evolutionary spectrum of SCC.
Proposed alternative names reflect the developmental connection between AK and early-stage squamous cell carcinoma.

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Description

This quiz reviews the clinical, dermoscopic, and therapeutic aspects of actinic keratoses as discussed in recent literature. Understanding these factors is essential for effective diagnosis and treatment in dermatology. Test your knowledge on the multifaceted approach to managing actinic keratoses.