Smartphones won’t make you grow horns—but neglecting a worsening skin cancer lesion for years could do the trick.

Recently, doctors in the UK surgically removed a 14cm-long “dragon horn” from a man’s lower back. The 50-year-old patient reported that it had been growing for at least three years.

The doctors determined that the “gigantic” skin growth was a cutaneous squamous cell carcinoma (cSCC)—a type of skin cancer that causes growing, scaly bumps on the top layer of skin.

While SCC is a very common type of skin cancer, the man’s case is rare, the doctors report in the journal BMJ Case Reports this week. Such lesions are typically caught much earlier. But in this case, doctors found “an extremely large well-differentiated SCC that was neglected by a patient,” even though he was “living in a developed country with access to free healthcare.”

“This highlights that despite current public skin cancer awareness and rigorous healthcare measures, cases like this can still arise and slip through the net,” they conclude.

Cases of SCC are typically seen in those with light skin, who have a lot of sun exposure, are older, have a weakened immune system, or have had certain chemical exposures, such as arsenic.

In this case, the man was a light-skinned manual laborer, but he reported no other clear risk factors. He had no significant sun exposure, no personal or family history of skin cancers, and was not immunosuppressed. Also unusual, his lymph nodes weren’t swollen—a common, nonspecific sign that the body is fighting off an infection or disease, such as skin cancer.

There was only “an enormous cutaneous horn on the lower back measuring 140×60×55mm,” the doctors report.

To treat the woefully neglected cancer, doctors surgically removed the horn, taking out several millimeters of peripheral tissue to ensure no cancer was left behind. Tests indicated that they caught it all, and the doctors patched the resulting gaping wound on the man’s back with skin from his thigh.

While the surgery seems to have been a success, the doctors report that SCC should be diagnosed and treated earlier, “before becoming ‘dragon horns.’”

BMJ Case Reports, 2020. DOI: 10.1136/bcr-2019-233305 (About DOIs).