protocol initiated Jan 25, 2022 by Mohammad Obeidat MD (Pathology) and Henry Hoffman MD (Otolaryngology)
Background
Parotid gland oncocytomas are benign tumors occuring primarily in the elderly - presenting usually as a painless, slow-growing mobile mass.
Oncocytomas are also known as oxyxphilic adenomas or mitochondriomas (Imran 2019).
They are composed of epithelial sheets often with a central scar -usually well-cricumscribed and composed of layers of oncocytes. Oncocytes are mitochondrial-rich cells with eosinophilic granular cytoplasm with small round centrally located nuclei (Imran 2019).
A theory of tumorigeneis is that aging causes a functional exhaustion of mitochondrial enzymes resulting in a compensatory hyperplasia of mitochondria (Sharma 2018) More than one oncocytic variant can exist in a single parotid gland - leading to the hypothesis of tumorigenesis from a common mitochondrial defect (Capone 2002).
Ultrasound evaluation shows well defined hypoechoic lesion with doppler analysis shwoing intratumoral vessels that may have a 'spoke-wheel pattern' (Crovino 2020).
Oncocytomas show FDG uptake on PET imaging.
References
Corvino A, Caruso M, Varelli C, Di Gennaro F, Pignata S, Corvino F, Vallone G, Catalano O. Diagnostic imaging of parotid gland oncocytoma: a pictorial review with emphasis on ultrasound assessment. J Ultrasound. 2021 Sep;24(3):241-247. doi: 10.1007/s40477-020-00511-5. Epub 2020 Jul 24. PMID: 32710434; PMCID: PMC8363736.
Sharma V, Kumar S, Sethi A. Oncocytoma Parotid Gland. Ann Maxillofac Surg. 2018 Jul-Dec;8(2):330-332. doi: 10.4103/ams.ams_154_17. PMID: 30693257; PMCID: PMC6327801.
Imran S, Allen A, Shokouh-Amiri M, Garzon S, Saran N. Parotid oncocytoma: CT and pathologic correlation of a rare benign parotid tumor. Radiol Case Rep. 2019 Nov 9;15(1):31-34. doi: 10.1016/j.radcr.2019.10.003. PMID: 31737142; PMCID: PMC6849430.
Capone RB, Ha PK, Westra WH, Pilkington TM, Sciubba JJ, Koch WM, et al. Oncocytic neoplasms of the parotid gland: a 16-year institutional review. Otolaryngol Head Neck Surg 2002;126(6):657–62. doi:10.1067/mhn.2002.124437.
Aydin F, Ayyildiz V, Gozgec E, Koksal A, Ogul H, Kantarci M. Multiple Oncocytomas of Bilateral Parotid Glands: A Case Report. Ear, Nose & Throat Journal. 2022;0(0). doi:10.1177/01455613221133227