Risk factors:
(1) local trauma, including surgery or dental manipulation
(2) ischemic injury
(3) recurrent vomiting
(4) smoking
(5) upper respiratory tract infection
Clinical features:
(1) one of the following:
(1a) painful, well-circumscribed ulcer with erythematous borders
(1b) painful, raised area of mucosa
(2) may be small or measure up to 3 cm in diameter
Histologic features:
(1) lobular infarction with or without spillage of mucin
(2) chronic inflammation
(3) pseudoepitheliomatous hyperplasia
(4) squamous metaplasia of acini and ducts
(5) preservation of the lobular architecture
Findings that exclude the diagnosis:
(1) perineural invasion
(2) lymphovascular invasion
(3) marked nuclear pleomorphism with atypical mitoses
(4) findings suggesting adenocarcinoma
(5) lymph node metastases
