Page 16 - New epidemiological and PSMA-expression based paradigms in salivary gland tumors

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Chapter 1
proteins also help in keeping the surfaces of the mucosa and teeth smooth, which prevents mechanical wear. The salivary gland function is regulated by the autonomous nervous system, via parasympathetic and sympathetic fibers that run in several nerves in the neck and face to the glands, such as the auriculotemporal nerve for the parotid.
Function is not only regulated by the nerves, but can also be affected by hormones, medication (e.g. antihypertensive medication) and diseases such as the rheumatic autoimmune disorder Sjogren’s syndrome.
Surgical pathology of salivary gland tumors
Surgery is sometimes needed to cure pathology such as salivary stones, infections, cysts, but also in case of neoplasms. Salivary gland tumors are rare tumors. Around 85% of these tumors are benign, but malignant salivary tumors also occur [2]. The most frequent salivary gland tumor is the salivary gland pleomorphic adenoma (SGPA) (Figure 4).
By definition, national cancer registries do not register benign tumors. Therefore, the SGPA incidence on a nationwide scale is difficult to determine. This tumor has a diversity of morphological presentations with a varying combination of different cell types (epithelial, myoepithelial and mesenchymal). It has two notorious characteristics that make it extra interesting. In case of damage to the tumor capsule during surgery, many small cell collections can be spilled that can cause multinodular recurrences. Solving this problem is a surgical challenge (also because of the location of the facial nerve) and in selected cases radiotherapy is thought to be of help, despite the fact that optimal proof of its effect is not yet available.
The SGPA sometimes turns into a malignant tumor, which is called a “carcinoma ex pleomorphic adenoma”, despite is benign background. The available evidence has shown presence of malignant cells and behavior, as well as genetic mutations in parts of the benign SGPA. However, the complete molecular cascade from a benign SGPA without genetic mutations to a subsequent malignant recurrence with presence of carcinogenic mutations, has never been reported. The malignant