Metachronous bilateral multifocal nodular oncocytic hyperplasia of the parotid gland

Bilateral multifocal nodular oncocytic hyperplasia of the parotid gland: a rare entity

“…Diffuse hyperplastic oncocytosis is described as a non-encapsulated lesion with the entire gland replaced by oncocytic cells 3 . Oncocytosis makes up 0.1% of salivary gland lesions 4 . Oncocytic carcinoma is the malignant counterpart of oncocytoma (malignant appearing oncocytic cells).…”

“…It mostly affects women in the sixth decade 1 . It is characterized histologically by the presence of multiple non-encapsulated nodules of oncocytic cells, that are interspaced with normal tissue 1 , 4 . In our case, the nodules were mainly composed of clear cells.…”

“…The pathogenesis of this condition is unclear, but mitochondrial dysfunction and defective cellular metabolism (responsible for mitochondrial hyperplasia and pleomorphism) have been suggested 4 .…”

“…Thus, the gold standard for precise diagnosis is histological exam 3 , 4 . Nevertheless, MNOH should be considered in the differential diagnosis of oncocytic neoplasms on FNA cytology especially when it shows a paucicellular specimen composed of small groups of oncocytic cells and even can favour it in elderly patients with multiple nodules 5 .…”

Nodular Oncocytic Hyperplasia of Bilateral Parotid Glands With Parapharyngeal Space Extension

“…5 To the best of our knowledge, only 11 patients with NOH of the parotid glands have been reported in 10 case reports published between 1999 and 2019 (Table 1). [6][7][8][9][10][11][12][13][14][15] Of the 12 patients, including ours, there were 9 (75%) females and 3 (25%) males with a median age of 67.9 years (range, 53-80 years). Half of the patients had bilateral lesions.…”