It is spontaneous condition of an unknown cause usually of the palate in which large area of the surface epithelium underlying connective tissue and all the associated minor salivary glands become necrotic while the ducts under go squamous metaplasia.
Usually the location is at the junction of the hard and the soft palatebut it may also be present at tongue, retromolar pad and the nasal cavity.
NSM is characterized by deep seated ulceration it is punched out
With in its deep crater are the gray granular lobules which represents the necrotic minor salivary glands.
It is 2-3 cm in diameter.
It is asymptomatic but there may be numbness or burning pain.
In the palatal epithelium there is no zone of ulceration which replaced by fibrin granulation tissue.
The lobules of minor salivary glands undergo coagulation necrosis.
There scattered neurophils and foamy histocytes present in zone of necrosis.
No treatment is required once the diagnosis is confirmed by histological examination .
The ulcer area heals by its self with in 1-3 months.