Keratoacanthoma
Keratoacanthoma is a relatively common low grade, rapidly growing, skin cancer tumor that originates in the pilosebaceous glands and closely resembles squamous cell carcinoma. In fact, strong arguments support classifying keratoacanthoma as a variant of invasive squamous cell carcinoma. In most pathology (biopsy) reports, dermatopathologists refer to the lesion as squamous cell carcinoma, keratoacanthoma-type. Recently, some have argued for a distinction between keratoacanthoma and squamous cell carcinoma based on gene expression or cutaneous marker.
Keratoacanthoma is characterized by rapid growth over a few weeks to months, followed by spontaneous resolution over 4-6 months in most cases. Keratoacanthoma may progress rarely to invasive or metastatic carcinoma. Whether these cases were squamous cell carcinoma or keratoacanthoma, the reports highlight the difficulty of distinctly classifying individual cases.
Keratoacanthoma is less common in darker-skinned individuals. The male to female ratio for keratoacanthoma is 2:1. Keratoacanthoma has been reported in all age groups, but incidence increases with age. It’s more common in people age 60 and over. It’s rare for anyone under age 20 to have keratoacanthoma.
The symptoms of keratoacanthoma are visual and last two to three months. First, keratoacanthoma shows a pimple, boil, round bump, small. Then, it grows into a lesion or wound and reaches a size of between 1 and 2 centimeters within a few weeks. The wound looks like a dome with a plug made of brown keratin, which is the same material as hair and skin.
If the brown keratin comes out, the keratoacanthoma will look like a crater. When it heals, it’ll flatten and leave a scar.
Usually, keratoacanthoma sees on skin that’s been exposed to the sun, like head, neck, arms, the backs of hands, and sometimes legs. It often starts in a hair follicle.
The exact cause of keratoacanthoma is unknown. But several potentiating factors should be considered:
- Sun exposure,
- Contact with chemical carcinogens, or cancer-causing chemicals,
- Smoking,
- Infection with some strains of a wart virus, such as human papillomavirus,
- Trauma,
- A weak immune system,
- Genetic factors.
Keratoacanthoma and squamous cell carcinoma consist of very similar epidemiological features. This means they develop at similar rates and have common causes. This suggests exposure to sunlight causes keratoacanthoma, and one of the main causes of squamous cell carcinoma is ultraviolet (UV) exposure.
Keratoacanthoma will go away on its own, but this can take many months. The most common treatment is surgery to remove the keratoacanthoma. The procedure may continue in the doctor’s chamber with medicine to numb the area around the tumor.
There are a few different surgeries which doctor may use. Like:
- Scrape off the tumor and seal up the wound.
- Apply liquid nitrogen to freeze and destroy the tumor. This is called cryosurgery.
- Cut the tumor out and use stitches to close the area.
- Remove one layer of tissue at a time and examine each one under a microscope to make sure all abnormal cells are gone. This is called Mohs surgery. It’s the most precise way to get rid of keratoacanthoma but also the most expensive.
If can’t perform the surgery, or if have multiple keratoacanthomas, can try other treatments. The medical treatments include:
- intralesional methotrexate
- injecting a folic acid that halts DNA synthesis and kills cancer cells
- Intralesional 5-fluorouracil, which is an injection that blocks cancer cells from reproducing,
- Topical 5-fluorouracil,
- Bleomycin, which is an anti-tumor agent that blocks cell cycles,
- A 25 percent solution of podophyllin,
- Oral acitretin, or chemical vitamin A,
- Oral isotretinoin,
- Retinoids that take by mouth
- Radiation,
- Steroids.
It’s not unusual for a single keratoacanthoma to shrink and disappear on its own after several months. But it may leave a worse scar than one from surgery. It could also come back, so it’s best to get it removed.
Consult a dermatologist to exclude invasive squamous cell carcinoma. If don’t treat it, keratoacanthoma can spread throughout the body.
- ABC Of Dermatology
- Clinical Dermatology
- Roxburgh’s common skin diseases.
Keratoacanthoma
TUI - Tibot Urgency Index
Keratoacanthoma is a relatively common low grade, rapidly growing, skin cancer tumor that originates in the pilosebaceous glands and closely resembles squamous cell carcinoma. In fact, strong arguments support classifying keratoacanthoma as a variant of invasive squamous cell carcinoma. In most pathology (biopsy) reports, dermatopathologists refer to the lesion as squamous cell carcinoma, keratoacanthoma-type. Recently, some have argued for a distinction between keratoacanthoma and squamous cell carcinoma based on gene expression or cutaneous marker.
Keratoacanthoma is characterized by rapid growth over a few weeks to months, followed by spontaneous resolution over 4-6 months in most cases. Keratoacanthoma may progress rarely to invasive or metastatic carcinoma. Whether these cases were squamous cell carcinoma or keratoacanthoma, the reports highlight the difficulty of distinctly classifying individual cases.
Keratoacanthoma is less common in darker-skinned individuals. The male to female ratio for keratoacanthoma is 2:1. Keratoacanthoma has been reported in all age groups, but incidence increases with age. It’s more common in people age 60 and over. It’s rare for anyone under age 20 to have keratoacanthoma.
The symptoms of keratoacanthoma are visual and last two to three months. First, keratoacanthoma shows a pimple, boil, round bump, small. Then, it grows into a lesion or wound and reaches a size of between 1 and 2 centimeters within a few weeks. The wound looks like a dome with a plug made of brown keratin, which is the same material as hair and skin.
If the brown keratin comes out, the keratoacanthoma will look like a crater. When it heals, it’ll flatten and leave a scar.
Usually, keratoacanthoma sees on skin that’s been exposed to the sun, like head, neck, arms, the backs of hands, and sometimes legs. It often starts in a hair follicle.
The exact cause of keratoacanthoma is unknown. But several potentiating factors should be considered:
- Sun exposure,
- Contact with chemical carcinogens, or cancer-causing chemicals,
- Smoking,
- Infection with some strains of a wart virus, such as human papillomavirus,
- Trauma,
- A weak immune system,
- Genetic factors.
Keratoacanthoma and squamous cell carcinoma consist of very similar epidemiological features. This means they develop at similar rates and have common causes. This suggests exposure to sunlight causes keratoacanthoma, and one of the main causes of squamous cell carcinoma is ultraviolet (UV) exposure.
Keratoacanthoma will go away on its own, but this can take many months. The most common treatment is surgery to remove the keratoacanthoma. The procedure may continue in the doctor’s chamber with medicine to numb the area around the tumor.
There are a few different surgeries which doctor may use. Like:
- Scrape off the tumor and seal up the wound.
- Apply liquid nitrogen to freeze and destroy the tumor. This is called cryosurgery.
- Cut the tumor out and use stitches to close the area.
- Remove one layer of tissue at a time and examine each one under a microscope to make sure all abnormal cells are gone. This is called Mohs surgery. It’s the most precise way to get rid of keratoacanthoma but also the most expensive.
If can’t perform the surgery, or if have multiple keratoacanthomas, can try other treatments. The medical treatments include:
- intralesional methotrexate
- injecting a folic acid that halts DNA synthesis and kills cancer cells
- Intralesional 5-fluorouracil, which is an injection that blocks cancer cells from reproducing,
- Topical 5-fluorouracil,
- Bleomycin, which is an anti-tumor agent that blocks cell cycles,
- A 25 percent solution of podophyllin,
- Oral acitretin, or chemical vitamin A,
- Oral isotretinoin,
- Retinoids that take by mouth
- Radiation,
- Steroids.
It’s not unusual for a single keratoacanthoma to shrink and disappear on its own after several months. But it may leave a worse scar than one from surgery. It could also come back, so it’s best to get it removed.
Consult a dermatologist to exclude invasive squamous cell carcinoma. If don’t treat it, keratoacanthoma can spread throughout the body.
- ABC Of Dermatology
- Clinical Dermatology
- Roxburgh’s common skin diseases.
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