Oncocytic metaplasia as a histopathological feature in a case of inflammatory fibrous hyperplasia: A case report

Oncocytic metaplasia refers to a metaplastic alteration occurring in duct and acinar cells, typically found in major or minor salivary glands, commonly associated with aging. Despite being infrequently reported, it appears to be an underrecognized phenomenon that may be linked to inflammatory fibrous hyperplasia (IFH). A 66-year-old caucasian female, who is a non-smoker and abstains from alcohol, presented with longstanding multiple nodular lesions along the mucosa of the maxillary alveolar ridge. Clinical examination led to a diagnosis of IFH, which was confirmed through excisional biopsies. Histopathological examination revealed characteristic features of IFH alongside ductal structures exhibiting notable cell hyperplasia with oncocytic metaplasia. These cells displayed an irregular arrangement of single and double-layered structures with cystic dilatation. Additionally, some excretory ducts exhibited focal hyperplasia and thickening. This case underscores the co-occurrence of oncocytic metaplasia with IFH, emphasizing the significance for pathologists to identify such features to prevent misdiagnosis and unwarranted investigations.