Skin cancer: Nursing pathophysiology

Skin cancer is a malignant proliferation of skin cells and includes basal cell, carcinoma, squamous cell, carcinoma, and melanoma.

Ok. Let's actually start with a quick review.

The skin is the largest organ in the body and provides important functions like protection, sensory perception, temperature regulation and Vitamin D production.

Its two main layers. The dermis and epidermis rest upon the hypodermis or a subcutaneous tissue, which is sometimes considered a third layer of the skin.

The hypodermis consists mainly of adipose or fat tissue that provides insulation and padding and loose connective tissue that helps anchor the skin to the underlying muscle.

Above the hypodermis is the dermis, which is made up of connective tissue that allows the skin to contract and stretch with body movements.

It also contains hair, follicle roots, nerves, oil and sweat glands, immune cells and blood and lymphatic vessels. The most superficial layer of the skin is the epidermis.

The epidermis is composed of stratified squamous epithelial cells called keratinocytes. The epidermis is divided into five layers or strata consisting of these cells.

The basal layer called stratum basale is the deepest layer here, stem cells called basal cells continuously divide and produce new keratinocytes.

As these new keratinocytes are formed, they move upward, pushing older cells toward the surface. In the process, the cells gradually flatten and become keratinized.

Meaning they fill with a protein called keratin, a strong waterproof protein that gives skin hair and nails strength. The basal layer also contains melanocytes.

These cells synthesize and secrete melanin the pigment that gives rise to skin color and helps protect against UV radiation.

The next layer, the stratum spinosum is composed of irregularly shaped skin cells as they move upward, they begin to flatten and form the third layer.

The stratum granulosum. Here, the cells continue to flatten out and die and begin the process of keratinization.

The next layer up is the stratum lucidum composed of dead translucent skin cells. This layer is only found in thick skin, like the palms of the hand and soles of the feet.

Finally, the stratum corneum is the outermost layer of skin composed of many layers of flat dead cells that are continuously shed or desquamated and replaced by newer cells from the underlying layers.

So, skin cancer is caused by mutations that commonly involve tumor suppressor genes which suppress uncontrolled cell division or proto oncogenes, which help regulate normal cell growth.

Risk factors include exposure to UV radiation like from sunlight or tanning beds, especially in those with light skin hair or eyes or in those who spend a lot of time outside.

Consequently, cancers can form in areas with the most exposure to the sun, like the face ears, neck and upper extremities.

Additionally, immunosuppression, a family history of skin cancer and exposure to carcinogens such as coal tar radium and arsenic can increase the risk of skin cancer.

All right. Now, when mutations to the DNA occur, it leads to loss of regulatory function, allowing cells to divide uncontrollably.

Leading to tumor development. Skin cancer is classified based on the type of cell from which the tumor arises.

So, basal cell carcinoma arises from basal cells in the stratum basale. Melanoma arises from melanocytes in the stratum basale and squamous cell carcinoma arises from squamous keratinocytes in the stratum spinosum as the tumor grows, some tumors cause new capillary blood vessels to form a process called angiogenesis to provide the tumor with oxygen and nutrients.

Ok. So, clinical manifestations depend on the type of skin cancer.

Basal cell carcinoma typically appears as a slightly raised pearly white or ivory colored nodule with small blood vessels visible on the surface known as telangiectasis.

The center of the nodule is often depressed, giving a rolled border appearance and the tumor surface may crust as it grows.

Basal cell carcinoma usually grows slowly. Although metastasis is rare, this type of cancer can invade surrounding tissue causing manifestations related to tissue destruction.

Next, squamous cell carcinoma usually appears as scaly flat or slightly raised reddish lesions with irregular borders and a central ulceration lesions may also bleed easily.

Squamous cell carcinoma may spread to regional lymph nodes but similar to basal cell carcinoma. It rarely metastasizes.

Lastly, melanoma can present as asymmetrical lesions with variable colors including black, brown, red, tan, gray or white.

It typically has an irregular or poorly defined border and may quickly exceed six millimeters which is roughly the size of a pencil eraser.

Melanoma can evolve quickly by infiltrating the lymphatic vessels and metastasizing to other organs. This can cause systemic symptoms depending on the location to help.

Remember, these characteristics of lesions suspicious for Melanoma use the ABCD E mnemonic where A stands for asymmetry, B for border irregularity, C for color variation, D for diameter greater than six millimeters and E for evolving.

All right. It's a quick recap.

Skin cancer is a malignant proliferation of skin cells. Skin cancer is classified based on the cell from which the tumor arises and includes basal cell carcinoma arising from basal cells, squamous cell carcinoma, arising from squamous keratinocytes and melanoma arising from melanocytes.