7 Key Symptoms of Squamous Cell Carcinoma of the Skin You Should Know

Squamous cell carcinoma of the skin is the second most common type of skin cancer, affecting millions of people worldwide each year. This form of cancer develops in the squamous cells that make up the middle and outer layers of the skin. While squamous cell skin cancer is generally treatable when detected early, understanding its symptoms is crucial for prompt medical intervention and better outcomes.

Recognizing the warning signs of squamous cell carcinoma can be challenging, as it may initially appear as a minor skin change or irritation. However, being aware of the characteristic symptoms can help you identify potential concerns early and seek appropriate medical evaluation. In this comprehensive guide, we’ll explore the key symptoms of squamous cell carcinoma, helping you understand what to look for and when to consult a healthcare professional.

1. Firm, Red Nodules on the Skin

One of the most common symptoms of squamous cell carcinoma is the appearance of firm, red nodules on sun-exposed areas of the body. These nodules are typically solid to the touch and may feel like a small, hard bump beneath the skin’s surface.

These nodules often develop on areas that receive frequent sun exposure, including:

• Face and ears
• Neck and chest
• Arms and hands
• Shoulders and back

The nodules associated with squamous cell carcinoma are usually painless in the early stages, though they may become tender as they grow. Unlike typical pimples or skin irritations, these nodules persist over time and don’t resolve on their own. They may vary in size from a few millimeters to over a centimeter in diameter, and their firm texture distinguishes them from softer, fluid-filled cysts or lipomas.

The color of these nodules can range from pink to deep red, and they often have a smooth or slightly rough surface. In early stage 1 squamous cell carcinoma, these nodules may be relatively small and easy to overlook, which is why regular skin examinations are essential for those at higher risk.

2. Rough, Scaly Patches That Don’t Heal

Rough, scaly patches on the skin, known medically as actinic keratoses, can be precursors to or early signs of squamous cell carcinoma. These patches feel rough and sandpaper-like to the touch and may appear slightly raised above the surrounding skin.

Key characteristics of these scaly patches include:

• Persistent roughness that doesn’t smooth out over time
• Flat or slightly elevated appearance
• Color ranging from skin-toned to pink, red, or brown
• Tendency to develop in sun-damaged areas
• May itch, burn, or feel tender

These patches can develop gradually over months or years, making them easy to dismiss as simple dry skin or age spots. However, when these scaly areas fail to respond to moisturizers or persist for more than a few weeks, they warrant medical evaluation. The patches may measure anywhere from a few millimeters to several centimeters across and can sometimes merge together to form larger affected areas.

In some cases, these rough patches may become thicker and more horn-like in texture, a condition known as cutaneous horn. When squamous cell cancer develops from these patches, they may begin to bleed easily, crust over repeatedly, or develop an open sore that doesn’t heal properly.

3. Open Sores or Ulcers That Won’t Close

One of the more concerning symptoms of squamous cell carcinoma is the development of open sores or ulcers that refuse to heal, even after several weeks. These persistent wounds are a hallmark sign that something more serious than a simple skin injury may be occurring.

Characteristics of these non-healing sores include:

• Bleeding that occurs easily with minimal trauma or friction
• Repeated crusting and scabbing without complete healing
• Raised, rolled edges around the ulcerated area
• Oozing or discharge from the wound
• Central depression or crater-like appearance

These sores typically appear in areas of chronic sun exposure or previous skin damage. Unlike normal cuts or abrasions that progress through predictable stages of healing, these wounds seem to heal partially before breaking down again. The cycle of scabbing, bleeding, and re-opening is particularly characteristic of invasive squamous cell carcinoma.

The edges of these ulcers may feel firm and may be slightly raised compared to the surrounding skin. The base of the ulcer might appear red, pink, or have a granular texture. Some patients notice that these sores bleed spontaneously, particularly after washing the area or when clothing rubs against them. The persistent nature of these wounds—lasting more than four to six weeks—is a critical warning sign that should prompt immediate medical evaluation.

4. Wart-Like Growths on the Skin

Squamous cell carcinoma can sometimes manifest as wart-like growths that may be mistaken for common warts or other benign skin conditions. These growths have a distinctive appearance that sets them apart upon closer examination.

Features of wart-like squamous cell carcinoma growths:

• Dome-shaped or cauliflower-like appearance
• Rough, irregular surface texture
• May develop a thick, crusted top layer
• Tend to grow steadily rather than remaining stable
• Can develop on both sun-exposed and protected areas
• May have areas of bleeding or ulceration within the growth

These wart-like lesions are particularly common in areas of the body that have experienced chronic irritation, previous burns, or long-term sun exposure. While they may initially resemble viral warts, they differ in several important ways: they typically occur in older adults rather than children, they don’t respond to wart treatments, and they continue to grow progressively over time.

The texture of these growths can be quite varied, ranging from soft and friable (easily crumbled) to hard and horn-like. Some may develop a keratinized surface, appearing white or yellow due to accumulated keratin. Unlike benign warts, which often have tiny black dots (thrombosed capillaries) visible on their surface, squamous cell carcinoma wart-like growths may show irregular blood vessels or areas of discoloration.

5. Changes in Existing Scars or Skin Conditions

An often-overlooked symptom of squamous cell carcinoma is the development of cancer within areas of previously damaged or scarred skin. This type of squamous cell cancer, known as Marjolin’s ulcer when it develops in scars, can occur years or even decades after the original injury.

Warning signs in existing scars or chronic skin conditions include:

• New growth or thickening within an old scar
• Changes in color or texture of previously stable scar tissue
• Development of nodules or lumps in areas of chronic skin inflammation
• Ulceration or breakdown of previously healed tissue
• Increased sensitivity, pain, or itching in old scars
• Bleeding from previously stable scar tissue

Squamous cell carcinoma can develop in various types of chronic skin conditions, including burn scars, surgical scars, areas of chronic venous ulcers, sites of chronic osteomyelitis, and regions affected by chronic inflammatory skin diseases. The cancer typically arises in scars that are more than 20 years old, though it can occur sooner in some cases.

The appearance of these changes can be subtle initially. You might notice that an old scar that has been stable for years begins to develop a small bump or becomes slightly raised. The tissue may feel firmer than the surrounding scar tissue, or you might observe areas of redness or increased vascularity. As the cancer progresses, more obvious signs like ulceration, persistent crusting, or rapid growth become evident.

People with chronic wounds, such as diabetic ulcers or pressure sores that have been present for extended periods, should be particularly vigilant about any changes in the wound’s character, as these can also be sites where squamous cell carcinoma may develop.

6. Painful or Tender Lesions

While many early-stage squamous cell carcinomas are painless, some patients experience pain or tenderness as a presenting symptom. This is particularly true as the cancer advances or when it involves sensitive areas of the body.

Pain-related symptoms of squamous cell carcinoma include:

• Spontaneous pain or discomfort in the affected area
• Tenderness when touching or pressing on the lesion
• Burning or stinging sensations
• Pain that increases as the lesion grows
• Radiating discomfort to surrounding tissues
• Sensitivity to temperature changes

The development of pain in a skin lesion can indicate several things: the cancer may be growing deeper into the skin layers, it may be pressing on nerve endings, or there may be inflammation or secondary infection in the area. Invasive squamous cell carcinoma that extends into deeper tissues is more likely to cause pain than superficial lesions.

Some patients describe the pain as a constant dull ache, while others experience sharp, intermittent discomfort. The pain may worsen with touch, pressure from clothing, or exposure to extreme temperatures. In areas where the skin is naturally more sensitive—such as the lips, genitals, or areas near mucous membranes—even early-stage lesions may produce noticeable discomfort.

It’s important to note that the presence or absence of pain should not be used as the sole indicator of whether a lesion is concerning. Many advanced squamous cell carcinomas remain painless, while some benign conditions can be quite painful. Any persistent, unexplained pain in a skin lesion should be evaluated by a healthcare professional.

7. Rapid Growth or Changes in Appearance

One of the most significant warning signs of squamous cell carcinoma is rapid growth or noticeable changes in a skin lesion’s appearance over a relatively short period. This symptom is particularly important because it indicates active disease progression.

Signs of concerning growth or change include:

• Visible increase in size over weeks or months
• Changes in shape from regular to irregular borders
• Color variations, including areas of red, white, pink, or brown
• Development of new symptoms in a previously asymptomatic lesion
• Transformation from flat to raised, or smooth to rough texture
• Spread to surrounding skin or development of satellite lesions

Rapid growth is particularly concerning because it may indicate an aggressive form of squamous cell carcinoma or progression from early stage to invasive squamous cell carcinoma. While some squamous cell cancers grow slowly over years, others can develop and expand within a few months.

Patients should pay attention to any lesion that doubles in size within a few months or shows dramatic changes in appearance. Taking regular photographs of concerning lesions can be helpful in documenting changes over time, providing valuable information for your healthcare provider during evaluation.

The borders of a growing squamous cell carcinoma often become more irregular and poorly defined as the cancer invades surrounding tissue. You might notice that what started as a small, well-defined spot has developed unclear edges that blend into the surrounding skin. Color changes can be particularly diverse, with some areas appearing darker due to increased vascularity or inflammation, while others may appear lighter or whitish due to keratin accumulation.

In some cases, you might observe the development of small satellite lesions around the main tumor, indicating local spread. This is more common with aggressive or neglected tumors and represents a more advanced stage of disease requiring prompt medical attention.

Main Causes of Squamous Cell Carcinoma

Understanding the causes of squamous cell carcinoma can help you better assess your risk and take appropriate preventive measures. While multiple factors can contribute to the development of this skin cancer, several primary causes have been clearly identified through medical research.

Ultraviolet (UV) Radiation Exposure

Cumulative exposure to UV radiation from the sun is the leading cause of squamous cell carcinoma. Years of sun exposure damage the DNA in skin cells, leading to mutations that can result in cancer. This includes both UVA and UVB rays, which penetrate the skin and cause cellular damage over time. People who work outdoors, live in sunny climates, or have a history of sunburns are at significantly higher risk.

Tanning Beds and Artificial UV Sources

The use of tanning beds and sunlamps significantly increases the risk of developing squamous cell carcinoma. These artificial UV sources can be even more intense than natural sunlight and contribute to cumulative UV damage. Studies have shown that people who use tanning beds before age 30 have a substantially elevated risk of developing skin cancer later in life.

Fair Skin and Genetic Factors

People with fair skin, light hair, and light-colored eyes are at higher risk for squamous cell carcinoma because they have less melanin, which provides some natural protection against UV radiation. Certain genetic conditions, such as xeroderma pigmentosum and albinism, dramatically increase skin cancer risk. Additionally, having a family history of skin cancer can elevate your personal risk.

Weakened Immune System

Individuals with compromised immune systems are significantly more susceptible to squamous cell carcinoma. This includes people who have received organ transplants and take immunosuppressive medications, those living with HIV/AIDS, individuals undergoing chemotherapy, and people with conditions that affect immune function. A weakened immune system is less effective at identifying and destroying abnormal cells before they become cancerous.

Human Papillomavirus (HPV) Infection

Certain strains of HPV have been linked to the development of squamous cell carcinoma, particularly in areas such as the genitals, mouth, and throat. While HPV is more commonly associated with cervical and oropharyngeal cancers, it can also play a role in some cases of squamous cell skin cancer, especially in individuals with weakened immune systems.

Exposure to Carcinogenic Chemicals

Prolonged exposure to certain chemicals and toxins can increase the risk of squamous cell carcinoma. This includes arsenic (found in contaminated water or certain occupational settings), coal tar, petroleum products, and certain heavy metals. People who work in industries involving these substances may have elevated risk if proper protective measures aren’t used.

Chronic Inflammation and Skin Conditions

Areas of the skin that have experienced chronic inflammation, long-standing wounds, or persistent infection are at increased risk for developing squamous cell carcinoma. This includes chronic leg ulcers, burn scars, areas of radiation damage, and sites of chronic inflammatory skin conditions that have been present for many years.

Prevention Strategies

While not all cases of squamous cell carcinoma can be prevented, there are several evidence-based strategies that can significantly reduce your risk of developing this type of skin cancer.

Sun Protection Measures

Protecting your skin from UV radiation is the most important preventive measure you can take. Apply broad-spectrum sunscreen with SPF 30 or higher to all exposed skin, even on cloudy days, and reapply every two hours or after swimming or sweating. Seek shade during peak sun hours (10 AM to 4 PM), and wear protective clothing including long sleeves, pants, wide-brimmed hats, and UV-blocking sunglasses. Remember that sun damage is cumulative, so consistent protection throughout your lifetime is essential.

Avoid Tanning Beds

Complete avoidance of tanning beds and artificial UV sources is one of the most straightforward ways to reduce your risk of squamous cell carcinoma. There is no safe amount of artificial tanning, and the risks far outweigh any cosmetic benefits. If you desire a tanned appearance, consider using self-tanning products that don’t involve UV exposure.

Regular Skin Examinations

Performing monthly self-examinations of your entire body can help you identify suspicious changes early. Use a full-length mirror and a hand mirror to check hard-to-see areas, or ask a partner to help. Look for any new growths, changes in existing moles or lesions, or any of the symptoms described in this article. Additionally, schedule annual full-body skin examinations with a dermatologist, especially if you have risk factors for skin cancer.

Protect Scarred or Damaged Skin

If you have areas of scarred or chronically damaged skin, take extra care to protect these areas from sun exposure and monitor them closely for changes. Cover scars with clothing or sunscreen when outdoors, and report any changes in old scars to your healthcare provider promptly.

Maintain a Healthy Immune System

Support your immune system through healthy lifestyle choices, including a balanced diet rich in fruits and vegetables, regular physical activity, adequate sleep, stress management, and avoiding smoking. If you take immunosuppressive medications, work closely with your healthcare team to monitor your skin health and receive regular screenings.

HPV Vaccination

While primarily designed to prevent cervical and other cancers, HPV vaccination may offer some protection against HPV-related squamous cell carcinomas. Talk to your healthcare provider about whether HPV vaccination is appropriate for you or your children.

Workplace Safety

If your occupation involves exposure to chemicals, radiation, or prolonged sun exposure, follow all safety protocols, use appropriate protective equipment, and participate in recommended health screenings. Employers in certain industries are required to provide protective measures for workers at risk of occupational skin cancer.

Frequently Asked Questions

What does early stage squamous cell carcinoma look like?

Early stage squamous cell carcinoma often appears as a small, firm, red nodule or a rough, scaly patch on sun-exposed skin. It may resemble a persistent pimple, wart, or area of irritated skin that doesn’t heal within a few weeks. Early lesions are typically small (a few millimeters) and may be flat or slightly raised.

How quickly does squamous cell carcinoma grow?

The growth rate of squamous cell carcinoma varies considerably. Some tumors grow slowly over several months to years, while others can develop and expand within weeks to months. Generally, squamous cell carcinoma grows faster than basal cell carcinoma, and invasive forms tend to progress more rapidly than superficial lesions.

Can squamous cell carcinoma spread to other parts of the body?

Yes, squamous cell carcinoma can metastasize (spread) to other parts of the body, though this occurs in a relatively small percentage of cases. The risk of metastasis is higher for larger tumors, deeply invasive lesions, tumors in certain locations (such as the lips or ears), and in people with weakened immune systems. This is why early detection and treatment are so important.

Is squamous cell carcinoma painful?

Squamous cell carcinoma can be painful, but many cases are painless, especially in the early stages. Pain or tenderness is more common as the tumor grows larger or invades deeper tissues, or when the cancer develops in sensitive areas. The presence or absence of pain should not be used to determine whether a lesion is concerning.

What’s the difference between squamous cell carcinoma and basal cell carcinoma?

Both are types of skin cancer that develop from different skin cells. Squamous cell carcinoma originates in squamous cells in the outer layers of skin and typically appears as scaly patches, red nodules, or non-healing sores. Basal cell carcinoma develops from basal cells in the deepest layer of the epidermis and often appears as pearly or waxy bumps. Squamous cell carcinoma is more likely to spread to other parts of the body than basal cell carcinoma.

Who is most at risk for developing squamous cell carcinoma?

People at highest risk include those with fair skin, a history of extensive sun exposure or sunburns, older adults (risk increases with age), individuals who use or have used tanning beds, people with weakened immune systems, those with a personal or family history of skin cancer, and individuals with certain genetic conditions. Occupations involving outdoor work or chemical exposure also increase risk.

Can squamous cell carcinoma come back after treatment?

Yes, squamous cell carcinoma can recur after treatment, which is why ongoing monitoring is essential. The recurrence rate depends on various factors including the size and location of the original tumor, whether it was completely removed, the depth of invasion, and individual risk factors. Regular follow-up appointments with your healthcare provider are crucial for detecting any recurrence early.

Should I see a doctor for every unusual skin growth?

While not every unusual skin growth is cancerous, you should see a healthcare provider if you notice any new growth that persists for more than a few weeks, any sore that doesn’t heal, changes in existing moles or spots, or any of the symptoms described in this article. It’s always better to have a suspicious lesion evaluated and found to be benign than to delay seeing a doctor for something that turns out to be serious.

How is squamous cell carcinoma diagnosed?

Diagnosis typically involves a visual examination by a healthcare provider, often a dermatologist, followed by a skin biopsy if cancer is suspected. During a biopsy, a small sample of the suspicious tissue is removed and examined under a microscope by a pathologist to determine if cancer cells are present and, if so, what type and how aggressive they are.

What areas of the body are most commonly affected?

Squamous cell carcinoma most commonly develops on sun-exposed areas including the face, ears, neck, lips, backs of the hands, forearms, shoulders, and scalp (particularly in men with hair loss). However, it can develop anywhere on the body, including areas not typically exposed to sun, especially in people with other risk factors like weakened immune systems or chronic skin conditions.

References:

• The Skin Cancer Foundation – Squamous Cell Carcinoma
• American Cancer Society – Basal and Squamous Cell Skin Cancer
• Mayo Clinic – Squamous Cell Carcinoma of the Skin
• American Academy of Dermatology – Squamous Cell Carcinoma
• National Center for Biotechnology Information – Squamous Cell Skin Cancer