Salivary gland biopsy

You have three pairs of major salivary glands. The parotid glands sit in front of each ear and over the angle of the jaw. The submandibular glands sit under the jawbone. The sublingual glands lie under the tongue. Hundreds of tiny minor salivary glands line the mouth and throat.

A lump in one of these glands is often noticed while shaving or washing, or found on a scan. Many are harmless. About 4 out of 5 parotid tumors are benign, most commonly a pleomorphic adenoma or a Warthin tumor. Lumps in the submandibular gland are less common but more often cancer, close to half. Other causes include swollen lymph nodes inside the gland, cysts, stones and inflammation.

On ultrasound, the parotid gland looks like a bright, fine-textured gray area just under the skin in front of the ear. A tumor is usually a darker, rounded spot within it. We can see blood vessels around it and plan a path that avoids them.

Most salivary gland tumors, even benign ones, are eventually removed with surgery because they tend to keep growing. So why biopsy first? Because the type of tumor changes the plan. A biopsy helps your surgeon decide how much of the gland to remove, whether lymph nodes in the neck also need attention, and whether surgery is needed at all.

The biopsy is usually requested by an ear, nose and throat (ENT) surgeon after a CT, MRI or ultrasound.

We often use both in one visit. Salivary gland results are reported using a system called the Milan system, which sorts results into groups from nondiagnostic to malignant, much like thyroid results.

Salivary gland tumors come in dozens of types, and a small cluster of cells does not always tell them apart. That is why I often take a thin core as well as fine needle samples when the lump is solid. I map the blood vessels on ultrasound first and keep the needle in the outer part of the gland, away from where the facial nerve runs.

Fabio Komlos, MD, interventional radiologist · About Dr. Fabio Komlos

1. 1
   Positioning

   You lie on your back with your head turned to the side away from the lump.

2. 2
   Ultrasound and numbing

   We find the lump with ultrasound, clean the skin and numb it and the tissue around the lump.

3. 3
   Taking the samples

   Watching on ultrasound, we take a few fine needle samples, a thin core, or both. You feel pressure, and a core needle makes a click.

4. 4
   Finishing up

   We press on the site for several minutes to limit bruising and apply a small bandage or skin glue.

1. Right after
   Rest for about 30 minutes with an ice pack. You can eat, drink and drive yourself home if you had no sedation.
2. First 1–2 days
   Mild soreness or swelling, sometimes worse with chewing or eating sour foods, which make the gland work. You can shower the same day.
3. Up to 2 weeks
   Any bruise fades. Skin glue falls off on its own.

Results usually take about 2 to 5 business days and go to the surgeon or doctor who ordered the biopsy. Some tumors need extra stains or genetic tests, which can take longer.

This biopsy is very safe. A bruise or small swelling is the most common side effect. Serious bleeding and infection are rare. Injury to the facial nerve, which moves the face, is extremely rare with an ultrasound-guided needle. Spread of tumor cells along the needle track has been a concern with some tumors, but it is very rare with modern thin needles. A sample that does not give an answer happens in a small share of cases.