| Oncocytoma | |
|---|---|
| Specialty | Oncology  |
Anoncocytoma is atumor made up ofoncocytes, epithelialcells characterized by an excessive amount ofmitochondria, resulting in an abundant acidophilic, granularcytoplasm.[1][2] The cells and the tumor that they compose are oftenbenign but sometimes may bepremalignant ormalignant.
An oncocytoma is anepithelial tumor composed of oncocytes, largeeosinophilic cells having small, round, benign-appearingnuclei with largenucleoli.[citation needed]
Oncocytoma can arise in a number of organs.[citation needed]
Renal oncocytoma is thought to arise from theintercalated cells ofcollecting ducts of the kidney. It represents 5% to 15% of surgically resectedrenalneoplasms.[citation needed]
Ansalivary gland oncocytoma (also known as anoxyphilicadenoma) is a well-circumscribed, benignneoplastic growth comprising about one percent of all salivary gland tumors. Thehistopathology is marked by sheets of large, swollenpolyhedral epithelial oncocytes, which are granularacidophilic parotid cells with centrally located nuclei. The granules are created by the mitochondria.[citation needed]
Salivary gland oncocytomas, 85 to 90 percent of which are located in theparotid gland, are firm, slowly growing, painless masses of less than 4 cm and may be bilateral. They are most common in females age 70 to 80.[citation needed]
Thyroid oncocytomas (also known asHürthle cell tumours) can be benign (adenomas) or malignant (carcinomas). Grossly, oncocytic adenomas are encapsulated, solid nodules with a characteristic brown cut surface. The gross appearance of a minimally invasive oncocytic carcinoma is indistinguishable to that of an adenoma, while widely invasive oncocytic carcinomas are obviously invasive macroscopically and display pervasive vascular invasion with multifocal involvement of the thyroid gland. There are no reliable cytologic features which distinguish oncocytic adenomas from carcinomas and the only criterion for a diagnosis of malignancy is the identification of transcapsular or vascular invasion.[citation needed]
Patients with thyroid oncocytomas present with a thyroid nodule, usually with normal thyroid function. If the tumor is big or invasive, there may be other symptoms such as difficulty swallowing or talking.[citation needed]
