Under the microscope, they look like the outlines of cells that used to be there. Pale, swollen, keratinized shapes with the nucleus gone, leaving only a faint shadow where it used to sit. Pathologists call them ghost cells, and when they appear in a jaw tumor alongside malignant epithelium, the diagnosis is ghost cell odontogenic carcinoma.
It is one of the least common cancers in medicine, accounting for roughly 0.23 percent of all odontogenic tumors, according to a systematic review in Head and Neck Pathology. The entire published record runs to about 65 cases. Most pathologists will finish a career without seeing one, which is exactly the problem.
