Oral squamous cell carcinoma associated with khat chewing.

The incidence of oral squamous cell carcinoma has been long associated with smoking, alcohol, and betel quid/areca nut chewing. This article presents a case of a 42-year-old female patient with squamous cell carcinoma of the floor of the mouth, associated with khat chewing. This relatively early presentation of oral squamous cell carcinoma may be linked to the synergistic effect of khat chewing and other known carcinogens such as polycyclic aromatic hydrocarbons and nitrosamines such as 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone, 4-(N-methyl-N-nitrosamino)-4-(3-pyridyl)-1-butanal. With the changing demographic structure and migration between countries, khat chewing is of increasing significance as it may contribute to the etiology of squamous cell carcinoma in developed countries.