Bowen's disease

Bowen's disease (syn: squamous cell carcinoma in situ, intraepithelial cancer) is a rare typical variant of noninvasive cancer, appears on the skin areas exposed to sunlight. This type of cancer usually develops in the elderly. The exact cause of development is unknown, although some risk factors have been identified. The lesions are usually painless. Treatment, as a rule, is surgical. The prognosis of the disease is favorable.

[1], [2]

Epidemiology

The prevalence of the disease varies depending on the region and ranges from 14.9 cases per 100,000 to 142 cases per 100,000.

The difference between the incidence of men and women is not. Most often develops in adulthood, with a high incidence in patients older than 60 years.

[3], [4], [5], [6], [7]

Causes of the bowen's disease

The exact cause of the disease is unknown

Risk factors

Like other forms of skin cancer, Bowen's disease develops due to chronic sun exposure and aging. The cause of the disease is also considered oncogenic papilloma virus (HPV 16, 2, 34, 35) and chronic intoxication with arsenic.

Persons with fair skin who spend a lot of time under direct sun, people who take cytotoxic drugs, patients after organ transplantation, and HIV-infected are in a group at high risk of developing this disease.

[8], [9], [10]

Pathogenesis

They reveal acanthosis with elongation and thickening of epidermal processes, hyperkeratosis, focal parakeratosis. Basal layer without any changes. Spiny cells are randomly distributed, many of them with a pronounced atypia of large hyperchromic nuclei. Often there are large multinucleated cells with intensely colored nuclei, metatarsome figures occur. Foci of dyskeratosis are formed from large rounded cells with a homogeneous eosinophilic cytoplasm and a pycnotic nucleus. Sometimes it is possible to detect foci of incomplete keratinization in the form of concentric stratifications of keratinizing cells. Reminiscent of "horny pearls." Some cells are highly vacuolated, resemble Paget cells, but the latter do not have intercellular bridges. When transferring Bowen's disease to invasive cancer, a deep immersion in the derma of the acanthotic cords occurs with a violation of the basal membrane and a pronounced polymorphism of the cells in these strands.

[11], [12], [13], [14], [15]

Symptoms of the bowen's disease

Characterized by the presence of a usually solitary, severely restricted lesion, rounded or oval contours, less irregularly shaped, with a slow peripheral growth with the formation of a slightly raised margin, peeling or covered with crusts. The surface is uneven, granular, may be slightly warty. There are surface erosion, ulceration with the formation of partially ulcerated and at the same time increasing ulcers. Most often, the foci are located on the head, hands, genitals, but can be on any part of the skin and mucous membranes. With prolonged course, transformation into a typical squamous cell carcinoma can occur.

[16], [17], [18]

Diagnostics of the bowen's disease

Diagnosis is based on the identification of characteristic symptoms, a detailed medical history and a thorough clinical examination. The diagnosis is confirmed by biopsy of the affected tissue.

[19], [20], [21],

Differential diagnosis

To differentiate Bowen's disease follows from seborrheic keratosis, in which pigmentation and intra-epidermal cysts are often expressed, the cells are darker and shallower, and their atypia is less pronounced.

Treatment of the bowen's disease

Treatment depends on each case and depends on many factors, such as:

• the location, size and thickness of the pathological focus;
• the presence or absence of certain symptoms;
• age and general health.

Photodynamic therapy (PDT), cryotherapy, local chemotherapy with 5-fluorouracil are used in the treatment. Recent studies (2013) showed good efficacy in the local therapy of 5% cream Imiquimod. Typically, apply the cream once or twice a day for at least two weeks.

Cryotherapy is most effective for a single and small amount of damage.

Some dermatologists prefer surgical intervention by excision of the pathological focus.

Prevention

The most effective way to prevent Bowen's disease is to limit the excess sun exposure by using clothing and sunscreen.

[22], [23], [24], [25], [26]

Forecast

Since Bowen's disease cells do not capture the dermis, the disease has a much better prognosis than invasive squamous cell carcinoma.

Without treatment, progression to invasive cancer occurs in 3-5% of cases, but metastases are rare.

[27], [28], [29], [30]