Oncocytic change may occur within normal glandular tissue, e.g. in salivary glands and in the thyroid.
In may also be associated with tumours in a different ways. Certain tumours may show oncocytic areas that co-exist with non-oncocytic areas, e.g. acinic cell tumours of the salivary gland. The glandular component of Warthin's tumour is typically oncocytic.
In the thyroid, oncocytic change within thyroid follicles is sometimes referred to as Hürthle cell change. Hürthle cells are also seen in Hashimoto's thyroiditis, but when neoplastic, Hürthle cell adenomas and adenocarcinomas are regarded as variants of thyroid follicular carcinomas.
If an oncocytic variant of a known tumour is excluded, especially in the salivary gland, exclusively oncocytic tumours are known as oncocytoma. They occur in a number of body sites, most commonly the kidney, thyroid and salivary glands.