Top: Rodent ulcer of twelve years duration (spontaneous cicatrization [sealing off; stopping spreading])

Bottom: Rodent ulcer of sixteen years duration (Terebant [Piercing] type)

Rodent ulcers” (also known as Jacobi ulcers) are so named due to their rat-gnawed appearance.
They are a manifestation of basal-cell carcinoma (BCC), and while they’re rarely fatal, they have the potential to be extremely disfiguring. Unlike most BCCs, rodent ulcers have significant central necrotization, leading to more tissue damage.

While the extreme destruction seen on these two patients is no longer commonplace in the developed world, treatment and removal of these ulcers can be very expensive, and they often recur, even with treatment. As they don’t often kill and often strike the very elderly, with removal frequently being more painful than the ulcer itself, basal-cell carcinoma is of the few cancers that is often simply monitored, rather than aggressively treated.

In Caucasian people, up to 30% of adults will develop some form of this cancer in their lifetimes. The most common cause is significant unprotected sun exposure, but genetics also plays a role in susceptibility. Thankfully, rodent ulcers are one of the less-common presentations.

Diseases of the Skin. James H. Sequeira, 1919.