Squamous cell skin cancer is a common type of skin cancer that develops in squamous cells, which form the outer layers of the skin. Prolonged ultraviolet radiation exposure is a major risk factor, although other medical and environmental factors can contribute. Understanding its causes, warning signs, and diagnostic procedures helps explain how this condition is identified.
Squamous cell skin cancer, also called cutaneous squamous cell carcinoma, occurs when squamous cells develop abnormal growth and multiply uncontrollably. It commonly appears on sun-exposed areas, including the face, ears, neck, hands, and arms. Although many cases can be treated successfully when identified early, some tumors can grow into surrounding tissues or spread to other parts of the body.
Squamous cell skin cancer develops through changes in the DNA of skin cells. Ultraviolet radiation from sunlight and indoor tanning equipment can damage cellular DNA, increasing the likelihood of abnormal cell growth. The condition can affect anyone, although certain characteristics and exposures increase the risk.
Important causes and contributing risk factors include:
Ultraviolet radiation exposure: Repeated exposure to sunlight and artificial tanning devices can damage skin cells over time. A history of sunburns and prolonged outdoor activities may increase risk.
Fair skin characteristics: People with lighter skin, light-colored eyes, and hair that burns easily may have a higher risk because their skin generally has less protective melanin.
Older age: The risk generally increases with age because ultraviolet radiation damage can accumulate over many years. However, younger individuals can also develop this cancer.
Weakened immune system: People taking immunosuppressive medicines or living with certain conditions that weaken immunity may have an increased risk of developing squamous cell carcinoma.
Previous skin damage: Chronic wounds, scars, radiation-damaged skin, and certain precancerous lesions, such as actinic keratoses, can be associated with an increased risk.
Exposure to certain chemicals: Long-term exposure to particular industrial chemicals, including arsenic, may contribute to skin cancer risk.
Diagnosis typically begins when a healthcare professional evaluates a persistent or unusual skin lesion. Squamous cell skin cancer may appear as a firm red nodule, a rough or scaly patch, a sore that does not heal, or a lesion that repeatedly crusts or bleeds. Its appearance can vary, and other skin conditions may look similar.
Diagnostic procedures help determine whether a suspicious growth contains cancerous cells and provide information about the tumor.
Skin examination: A dermatologist examines the suspicious area and may inspect other parts of the skin for additional lesions. The patient's medical history, sun exposure, and previous skin cancers may also be reviewed.
Skin biopsy: A small tissue sample is removed from the suspicious lesion and examined under a microscope. A biopsy is generally necessary to confirm the diagnosis.
Histopathological analysis: A pathologist evaluates the tissue sample to identify cancerous squamous cells and assess features such as tumor differentiation and growth patterns.
Assessment of tumor characteristics: The healthcare professional considers the lesion's size, depth, location, and other high-risk features to estimate the likelihood of local invasion or spread.
Additional investigations: Imaging tests or examination of nearby lymph nodes may be recommended when the cancer appears advanced or has features suggesting a higher risk of spreading. These tests are not routinely necessary for every case.
Recognizing suspicious skin changes and obtaining timely medical evaluation are important steps in identifying squamous cell skin cancer. Diagnosis through clinical assessment and biopsy helps healthcare professionals determine the nature of the lesion and plan appropriate management. Regular skin monitoring and sun protection can also help reduce preventable ultraviolet radiation exposure.