A carcinoma is a cancerous tumor of the epithelial tissue, the tissue beneath the skin. Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are skin cancers, but carcinoma can also affect the breasts, liver, lungs, neck and other parts.
According to the estimates by the Skin Cancer Foundation, about 5.4 million people in the United States get carcinoma-type skin cancer each year.
Of those, annually, BCC accounts for about 3.6 million cases, and SCC accounts for 1.8 million cases, amounting to 67% and 33%, respectively.
The third most common skin cancer is melanoma, which is more dangerous than carcinoma, because it can spread quickly if doctors do not detect it early.
Carcinomas are more common than melanomas and more treatable. Estimates suggest that in 2022, melanoma is likely to affect only about 197,700 people in the U.S.
This article looks at the diagnosis and treatment of the two most common carcinoma cancers, as well as other types of carcinoma.
A carcinoma, also known as nonmelanoma skin cancer, is a cancerous tumor of the epithelial tissue, which is a protective tissue that covers surfaces throughout the body.
The skin, or the epidermis, is a type of epithelial tissue. BCC and SCC affect the epidermis.
The epithelial tissue is
Healthcare professionals define the different carcinomas by the type of cell in which they occur.
BCC
BCC
BCC is unlikely to spread, but doctors who suspect that an individual has this type of carcinoma will still refer them for further assessment.
BCC typically affects older adults, with a mean diagnosis age of
SCC
Squamous cells make up most of the top layer of the epidermis. These cells are flat and scale-like.
SCC is the
Doctors who suspect SCC will provide a more urgent referral, as it is more likely to spread than BCC.
Other types of carcinoma
In addition to BCC and SCC, there are several other subtypes of carcinoma that affect the epithelial tissue other than the skin. They include:
- Adenocarcinoma: This is a type of carcinoma that
develops in the glands. It can affect many body parts or organs, including the lungs, breast, prostate, stomach, pancreas, and food pipe. - Renal cell carcinoma: This cancer
develops in the outer part of the kidneys. - Papillary urothelial carcinoma: This cancer
affects cells in the lower part of the kidneys or in the bladder. - Ductal carcinoma in situ (DCIS): This cancer
affects epithelial cells in the breast. - Invasive ductal carcinoma: This cancer
develops in the breast and is a more serious type of DCIS.
BCC and SCC are both skin tumors, and they share some characteristics. However, these skin lesions can vary in appearance.
Some carcinomas retain a flat surface and, as a result, can resemble healthy skin. Anyone with any unexpected lesions should contact a healthcare professional for a checkup and monitoring.
Other than its presence, a lump or lesion often causes no noticeable symptoms in its early stages. As a result, it might not be noticeable until it becomes relatively large, when it may itch, bleed, or cause pain.
BCC
BCC typically presents as a shiny papule, which is a small red or pink lump that grows slowly. A shiny, pearly, or waxy-looking border
A raised edge often rings a central ulcer, and unusually looking blood vessels might become visible. These may emerge as blue, brown, or black areas. Alternatively, they may be pink growths or pale or yellow areas that resemble scars.
Due to this wide range of appearances, obtaining an accurate diagnosis from a doctor is essential.
BCC might appear scaly, and it often causes recurrent crusting or bleeding. When it crusts over, it may resemble a healing scab, but sores can still appear. People with BCC often seek medical advice when they discover a sore that does not heal.
SCC
SCC
These lesions may bleed if a person bumps, scratches, or scrapes them. While they sometimes resemble warts, they can also appear as open sores with a crusted surface or raised edge.
It is vital to seek the opinion of a healthcare professional regarding the development of any new growths or any changes in preexisting skin growths or sores.
The following images show what different carcinoma lesions can look like on the skin.
Exposure to UV radiation from sunlight is the primary cause of carcinoma and other skin cancers.
Some people are more sensitive to UV light and more vulnerable to the effects of sunlight on cancer development than others. Additional UV exposure from tanning beds and UV drying lamps in nail salons, for example, can add to a person’s risk.
UV radiation can cause damage to the DNA in skin cells, leading to mutations during cell division and possibly resulting in skin cancer.
Factors that increase the likelihood of carcinoma include a personal history of skin cancer and radiation treatment for any form of cancer, particularly in childhood. A family history of cancer may also play a role.
Other risk factors include:
- having numerous, irregular, or large moles or freckles
- having an autoimmune condition, such as systemic lupus erythematosus
- having inherited conditions, such as xeroderma pigmentosum and nevoid BCC syndrome, also known as Gorlin syndrome
- having a weakened immune system, possibly due to HIV, receiving an organ transplant, or taking immunosuppressant drugs
- taking medicines that make the skin photosensitive, such as vandetanib (Caprelsa), vemurafenib (Zelboraf), and voriconazole (Vfend), although different classes and types
can cause sun sensitivity - having a human papillomavirus infection, particularly in people with a weakened immune system
SCC-specific risk factors
Actinic keratosis, which consists of rough, raised growths that cause precancerous changes in skin cells, is a risk factor specific to SCC.
These growths are the most common type of precancerous skin lesion. Without treatment, this condition may develop into skin cancer.
While UV radiation is the leading risk factor for SCC, the following skin damage can also increase the risk of this type of carcinoma:
- burns to the skin
- chemical damage
- exposure to X-ray radiation
BCC might also develop after exposure to X-ray radiation in childhood, although this is a
Race and ethnicity
People who have a tendency to burn before getting a suntan, such as those who have light skin, can be more at risk of some types of carcinoma. This includes people with blue or green eyes and those who have blond, red, or light brown hair.
However, people with dark skin can also get skin cancer. According to a 2016 study, SCC comprises
BCC is more common among people who are white, comprising about 65–75% of skin cancer cases in this group, compared with 20–30% among People of Color.
Moreover, BCC is more prevalent among Latino, Chinese, and Japanese populations than it is among African Americans and Asian Indians.
In many cases, people with dark skin receive a skin cancer diagnosis much later, when the condition is more life threatening.
To diagnose any form of skin cancer, a doctor will carry out a physical examination. They will examine the skin lesion and record its size, shape, texture, and other physical attributes.
They may also take a photo of the lesion for specialist review or to record its current size and appearance for future comparisons. The doctor will often check the rest of the body for additional skin symptoms.
They will also take a medical history focusing on the lesion and any related conditions, such as sunburn.
A doctor will urgently refer suspected cases of SCC for specialist investigation and treatment due to their tendency to spread. Suspected BCC tumors do not require such urgent referral, as they are less likely to spread.
If the doctor thinks that a lesion may be cancerous, they are also likely to perform a biopsy. There are four different types of skin biopsy, all of which involve the removal of skin tissue for laboratory assessment.
The different types are:
- Shave biopsy: Using a sharp surgical blade, the doctor shaves the top layers of skin cells, usually as far as the dermis but sometimes deeper. This type of biopsy often results in bleeding, but it is possible to stop this by cauterizing the wound, meaning sealing it using heat.
- Punch biopsy: The doctor uses a sharp, hollow surgical tool that resembles a tiny cookie cutter to remove a circle of skin from below the dermis. A person may need a single stitch to close the resulting wound.
- Incisional biopsy: The doctor removes part of the growth with a scalpel, cutting away a full-thickness wedge or slice of skin. This type of biopsy often needs more than one stitch afterward.
- Excisional biopsy: The doctor removes the whole growth and some surrounding tissue with a scalpel. The resulting wound usually requires stitches.
After taking the tissue sample, the doctor will send it to a pathology laboratory for examination under a microscope. The pathology team will assess the cells to look for cancerous traits. If cancer is present, the pathologists will determine its type.
The American Academy of Dermatology (AAD) recommends removing BCC lesions. While these lesions rarely spread, they can grow and become disfiguring and dangerous, depending on their location. The lesions can grow deep into the skin and affect the bones. In rare cases, BCC does spread aggressively.
Individuals with SCC may need to undergo tests for cancer in other tissues.
Additional tests usually involve imaging and may include:
Treatment for carcinoma is likely to be more effective in cases where a person identifies skin changes at an early stage and receives prompt medical attention.
In cases where cancer is responsible for skin changes, early treatment considerably improves the chance of survival and reduces the likelihood of significant tissue trauma and disfigurement.
BCC has an excellent survival rate, as it
Although SCC is more likely to spread, it is treatable in its early stages. Most treatments are over 95% effective.
However, if SCC spreads beyond the original site and reaches other systems in the body, it becomes much more life threatening. At this point, less than half of people who receive a diagnosis will likely die even with aggressive treatment.
Early identification is essential to improving a person’s outlook.
Below, we answer some common questions about carcinoma.
How can I prevent carcinoma?
The main risk factor for both types of carcinoma is UV light.
The best prevention strategy is to protect the skin from the sun. This includes staying in the shade during peak sun hours, wearing a hat and sunglasses, and using a broad-spectrum sunscreen with an SPF of
A person should also avoid using tanning beds, tanning parlors, and sunlamps. Additionally, people should regularly examine their skin.
How do I look for carcinoma on the skin?
Generally, a person should
People with dark skin may find it harder to notice signs of skin cancer. The AAD recommends they look for dark spots that grow, bleed, or seem to change, sores that do not heal, a dry or rough patch of skin, or a dark line underneath or around a fingernail or toenail.
How do doctors determine the carcinoma cancer stage?
To determine the cancer stage, a doctor will assess the size and depth of the carcinoma lesion and the extent to which it has spread to local and distant sites in the body, such as nearby lymph nodes or other organs.
The doctor
Is carcinoma always malignant?
Carcinoma is malignant cancer that begins in the skin or the tissues that line the organs inside the body.
What is the difference between carcinoma and sarcoma?
Sarcoma is cancer that begins in the bones or connective tissues inside the body. This can also include the blood vessels, nerves, or muscles.