Squamous Cell Carcinoma

Overview

Squamous cell carcinoma is a type of cancer that begins in squamous cells. These are flat, thin cells found in the outer layer of the skin and in the lining of many parts of the body, such as the mouth, throat, lungs, cervix and other organs. The most common form is cutaneous squamous cell carcinoma, which develops in the skin, often on areas exposed to the sun.

Many squamous cell carcinomas grow slowly and can be treated effectively when found early. However, some can grow deeper, spread to nearby tissues or lymph nodes, or appear in locations where treatment is more complex. The behavior of the cancer depends on where it starts, its size, depth, appearance under the microscope and the person’s overall health.

Early medical assessment is important. A specialist can determine whether a suspicious change is cancerous and recommend the most appropriate care plan.

Symptoms

Symptoms vary depending on where the squamous cell carcinoma develops. On the skin, it may appear as a new or changing spot that does not heal. Common skin-related signs include:

• A firm, red or pink bump
• A rough, scaly or crusted patch
• A sore that heals and then returns
• A wart-like growth
• A tender, bleeding or ulcerated area
• A thickened or raised area on a scar or long-standing wound

Squamous cell carcinoma can also develop on the lips, inside the mouth, in the throat, genital area or other organs. Possible symptoms in these areas may include:

• A persistent sore, lump or patch in the mouth or on the lip
• Pain, bleeding or difficulty swallowing
• Hoarseness or a lasting change in voice
• Unexplained swelling in the neck
• Persistent cough or breathing symptoms when the lungs are involved
• Unusual bleeding, discharge or discomfort in the genital area

These symptoms can have many causes, including non-cancerous conditions. A medical evaluation is needed to understand the cause.

Causes and Risk Factors

Squamous cell carcinoma develops when squamous cells acquire changes that allow them to grow in an uncontrolled way. Several factors can increase the risk, depending on the body area involved.

For skin squamous cell carcinoma, ultraviolet radiation from sunlight or tanning devices is a major risk factor. Risk may be higher in people with fair skin, a history of sunburns, frequent outdoor exposure or previous skin cancers. The cancer can also arise in areas of chronic inflammation, burns, scars or long-standing wounds.

A weakened immune system can increase the risk of certain squamous cell carcinomas and may also affect how they behave. This can occur after organ transplantation, with some immune-related conditions or during certain medical treatments.

Other risk factors may include tobacco exposure, heavy alcohol use, certain viral infections, occupational exposures and previous radiation treatment. The importance of each factor varies according to the cancer location. Not everyone with risk factors develops squamous cell carcinoma, and some people with the disease have no obvious risk factors.

Diagnosis

Diagnosis begins with a medical history and physical examination. For a skin lesion, the doctor examines the size, shape, color, texture and location of the area. For suspected squamous cell carcinoma in the mouth, throat, genital area or internal organs, the evaluation may include examination by a relevant specialist.

A biopsy is usually needed to confirm the diagnosis. During a biopsy, a small sample of tissue is removed and examined by a pathologist under a microscope. The pathology report helps identify the cancer type and may describe features such as depth of invasion, grade and whether the edges of the removed tissue are clear.

If the cancer appears larger, deeper, aggressive or located in a higher-risk area, additional tests may be recommended. These can include imaging scans, examination of nearby lymph nodes or other procedures to assess whether the cancer has spread. The exact diagnostic plan depends on the individual situation and the body area involved.

Treatment Options

Treatment depends on the location, size, depth and stage of the squamous cell carcinoma, as well as the patient’s general health and preferences. The goal is to remove or control the cancer while preserving function and appearance as much as possible.

For many skin squamous cell carcinomas, surgery is a common treatment. The cancer is removed along with a margin of surrounding tissue. In selected cases, specialized surgical techniques may be used to check the tissue edges during the procedure, especially in sensitive areas such as the face.

Radiation therapy may be considered when surgery is not suitable, when the cancer is in a difficult location, or after surgery if there is concern about remaining cancer cells or higher-risk features. Radiation uses targeted energy to damage cancer cells.

For more advanced squamous cell carcinoma, treatment may involve a combination of approaches. This can include surgery, radiation therapy and systemic treatments that work throughout the body. Systemic treatment may be considered if the cancer has spread, cannot be fully removed, or has returned after earlier treatment.

Supportive care is also important. Depending on the cancer location and treatment type, patients may need help with wound care, nutrition, speech, swallowing, pain control, rehabilitation or emotional support. Follow-up visits are used to monitor healing, check for recurrence and look for new lesions.

When to See a Doctor

Medical advice should be sought for any skin spot, sore or lump that is new, changing, bleeding, painful, crusting or not healing. It is also important to seek care for persistent mouth sores, hoarseness, swallowing problems, unexplained neck swelling, unusual bleeding or ongoing symptoms in any area lined by squamous cells.

People with a history of skin cancer, significant sun exposure, a weakened immune system, previous radiation treatment or chronic wounds should be especially attentive to changes and attend regular follow-up as advised by their doctor.

Early evaluation does not mean that a symptom is cancer. Many similar changes are benign or treatable for other reasons. However, timely assessment helps identify serious conditions earlier and allows the care team to discuss appropriate options if treatment is needed.