Oncocytosis (nodular oncocytic hyperplasia)

- Metaplastic and not neoplastic- Location : mostly parotid gland, rarely submandibular, minor salivary gland.- Age : older adults - Histology :Focal islands of Oncocytes in normal salivary gland tissue

Oncocytes are eosinophilic, granular , polyhedral cells -DDx: metastatic tumor -Tx: no treatment needed-Prognosis : excellent

Reference :oral & Maxillofacial Pathology B Neville, D Damm, C Allen, J Bouquot W B Saunders Co, (3rd E. )

Oncocytoma (oxyphilic adenoma)

Rare Neoplasm of salivary gland Age : older adults , 80 y commonlyPredilection : females , not significant Location: superficial lobe of parotid gland Clinical presentation: painless , slow growing and firm mass usually more than 4cm in sizeHistology : sheets of large oncocytes with central nuclei In an alveolar or granular pattern, Reduced stroma and lymphatic's +ve PTAH and -ve PAS Clear cells are present DDx: metastatic renal cell carcinoma Clear cell adenocarcinoma Tx: excision Prognosis : oncocytoma of Sino nasal gland could transform to low grade malignancy Otherwise good Reference :oral & Maxillofacial Pathology B Neville, D Damm, C Allen, J Bouquot W B Saunders Co, (3rd E. )

A 61-year-old white man presented with a 3-year history of painless right parotid gland fullness. One week prior, he developed sudden constant dull aching pain radiating from the right parotid region. Physical examination revealed diffuse enlargement of the parotid gland with a soft nontender right retromandibular mass. Intraoral examination revealed bulging of the right oropharynx. No facial nerve dysfunction or cervical lymphadenopathy was found.Total parotidectomy was performed by a combined transparotid-submandibular approach, sparing the facial nerve. The deep lobe of the parotid gland was removed intact by pericapsular dissection from the parapharyngeal space.

Reference:T.D. Shellenberger, M.D. Williams, G.L. Clayman, and A.J. KumarParotid Gland Oncocytosis: CT Findings with Histopathologic CorrelationAJNR Am J Neuroradiol April 2008 29: 734-736originally published online on February 13, 2008, 10.3174/ajnr.A0938.

Case (Part 1)

Microscopic examination of hematoxylin-eosin–stained formalin-fixed paraffin-embedded sections revealed. Islands of cells eosinophilic cytoplasm, with granular composition, polyhedral outlines, and prominent nucleoli. forming macroscopic nodules were present, with intervening ducts, acini, and fat in a background of morphologically normal serous acini (Fig 1B). In contrast to the superficial lobe mass, in which intervening normal structures were admixed with oncocytes, the deep lobe parapharyngeal mass contained a solid sheet of oncocytes with a central fibrous scar, consistent with an oncocytoma. No intervening normal parenchyma was identified within the mass (Fig 1D). At a higher magnification, both the superficial- and deep-lobe were found to have increased eosinophilic cytoplasm, with granular composition, polyhedral outlines, and prominent nucleoli. The oncocytes in both the hyperplastic and oncocytoma areas were bland, with no atypia or mitoses.

Reference:T.D. Shellenberger, M.D. Williams, G.L. Clayman, and A.J. KumarParotid Gland Oncocytosis: CT Findings with Histopathologic CorrelationAJNR Am J Neuroradiol April 2008 29: 734-736originally published online on February 13, 2008, 10.3174/ajnr.A0938.

Case (Part 2)

Case (histology)