Jill Biden underwent treatment for basal cell carcinoma. Explaining the common skin cancer

First Lady Jill Biden underwent a procedure to remove cancerous lesions Wednesday upon her return from Mexico, where she accompanied President Joe Biden to a summit with the Mexican president and Canadian prime minister earlier this week.

Jill Biden’s doctor, Dr. Kevin O’Connor, said the procedure, commonly known as Mohs surgery, successfully removed a small lesion above her right eye, and another on the left side of her chest.

“All cancerous tissue was successfully removed, and the margins were clear of any residual skin cancer cells,” O’Connor wrote in a memo. 

Doctors confirmed the lesions were basal cell carcinoma, a common type of skin cancer. Here’s what you need to know.

'This is alarming': Childhood vaccination rates drop as measles and polio outbreaks emerge

What is basal cell carcinoma?

Basal cell carcinoma is a common though, relatively harmless type of skin cancer. The cancer often appears in the head and neck area, which are often the most exposed to the ultraviolet rays of the sun, according to the Mayo Clinic. 

It forms in the basal cells, which are responsible for producing new skin cells as older ones die off, the Mayo Clinic said.

“It almost never spreads inside the body or anything scary like that,” said Dr. Abigail Waldman, director of the Mohs and Dermatologic Surgery Center at the Brigham and Women’s Hospital in Boston, Massachusetts.

XBB.1.5 is more contagious than Omicron: These products can help prevent infection

What is Mohs surgery?

Basal cell carcinoma is removed through a procedure called Mohs surgery, named after the physician who developed it. Unlike other cancer removal procedures, doctors check the margins around the tumor the same day, allowing them to go back and remove any additional skin cancer cells, Waldman said.

“It allows for clear margins and great cure rate,” Waldman told USA TODAY. “So the recurrence rate of these basal carcinomas after Mohs surgery is less than one percent.”

Waldman said the cancer is most common in older patients who have had years of exposure to the sun.

People with fair skin are also at greater risk of developing the cancer, according to the American Cancer Society. 

A similar type of skin cancer is squamous cell carcinoma, and they're often lumped together in statistics, Dr. William Dahut, the American Cancer Society's chief scientific officer said.

Is basal cell carcinoma melanoma?

No, neither basal cell carcinoma nor squamous cell carcinoma is melanoma.

Melanoma is considered the most serious kind of skin cancer and originates in a different cell.

"Basal cells can be taken out surgically," Dahut told USA TODAY. "While melanoma is at high risk, even with relatively small melanoma lesions, to spread to lymph nodes or spread elsewhere in the body."

"[Basal cell carcinoma] is a very different situation than most of the time when we talk about cancer," Dahut said. "Which is good news for the first lady."

What to know about the state of cancer: 1.95M people may be diagnosed with cancer in 2023

Signs of basal cell carcinoma

Basal cell carcinoma often appears as a small, raised pimple on the skin, often pink or pearly white, according to the Mayo Clinic. 

It tends to bleed, scab and resurface, Waldman said. If the lesion doesn't go away after 6-8 weeks, it could be a sign that the lesion is basal cell carcinoma.

It’s usually caught in skin cancer screenings, where a biopsy is done for confirmation.

Though basal cell carcinoma is highly treatable, those who develop are more likely to develop skin cancer in the future so doctors recommend having a screening done at least twice a year.

Because the cancer usually develops after years of sun exposure, doctors recommend wearing sunscreen and wearing hats.

This article originally appeared on USA TODAY: Basal cell carcinoma: what to know about Jill Biden's skin cancer