Epithelial-Myoepithelial Carcinoma (Salivary Gland), from the CureRays guide library.

Epithelial-myoepithelial carcinoma is a rare, usually low-grade salivary-gland cancer made of two cell types, treated mainly with surgery and, for higher-risk features, radiation — with a generally favorable outlook but a tendency to recur locally.

What it is.

Epithelial-myoepithelial carcinoma is an uncommon salivary-gland cancer named for the two kinds of cells it contains: inner duct-lining (epithelial) cells and outer 'myoepithelial' cells that normally help squeeze saliva out of the glands. It most often arises in the parotid gland (in front of the ear) and usually appears as a slowly growing, painless lump. Most of these tumors are low-grade and have a good outlook, but they are known for a tendency to come back in the same area if not fully removed, and a minority can transform into a higher-grade, more aggressive cancer. Because it is rare and can resemble other salivary tumors under the microscope, an experienced pathologist is important for diagnosis. Treatment centers on complete surgical removal, with radiation added when there are features that raise the risk of recurrence.

How radiation treats it.

Radiation damages the DNA inside cancer cells so they can no longer divide. For epithelial-myoepithelial carcinoma, surgery is the main treatment, but radiation is an important partner when the risk of the cancer returning is high — for example, when margins are close or positive, the tumor is high-grade or transformed, a nerve is involved, or lymph nodes are affected. It treats the microscopic cells left behind and lowers the chance of local recurrence, which is this tumor's main tendency. Intensity-modulated radiation shapes the dose around the salivary region while sparing healthy glands and swallowing muscles, and proton therapy can further spare nearby tissue for tumors near the skull base or when re-treating a recurrence. Radiation is painless during delivery, given over several weeks of daily sessions, and external-beam treatment leaves no radioactivity in the body.

The ways we can treat it.

Intensity-modulated radiation (IMRT). Beams are shaped around the salivary region to treat the tumor bed while sparing the other salivary glands, swallowing muscles, and jaw to limit dry mouth and other side effects.

Proton therapy (selected). Protons can reduce dose to nearby structures for tumors near the skull base or when re-treating a recurrence, lowering side effects.

Neutron / particle therapy (selected high-grade). For aggressive or transformed salivary cancers that resist standard radiation, specialized particle beams at expert centers can improve local control.

Questions we hear often.

Is epithelial-myoepithelial carcinoma usually serious? Most are low-grade and slow-growing with a favorable outlook after complete surgery. The main concern is a tendency to recur in the same area, which is why clear surgical margins and, for higher-risk features, radiation matter. A minority transform to a higher grade and need more intensive treatment.

Why might I need radiation if the tumor was removed? Radiation after surgery is recommended when there is a higher chance of microscopic cells being left behind — for example, close or positive margins, a high-grade tumor, nerve involvement, or lymph-node spread. It lowers the risk of the cancer returning in that area.

Will surgery affect my facial movement? Because the facial nerve runs through the parotid gland, surgeons take great care to identify and protect it. Most patients keep normal facial movement; temporary weakness can occur and usually improves. Your surgeon will discuss the risks specific to your tumor.

This guide is informational only. It is not medical advice — please confirm anything here with your care team.