How is adenoid cystic carcinoma diagnosed?

CT (computerised tomography) or MRI (magnetic resonance imaging) scans – special machines are used to scan and create pictures of the inside of your body. Before the scan you may have an injection of dye (called contrast) into one of your veins, which makes the pictures clearer. During the scan, you will need to lie still on an examination table. For a CT scan the table moves in and out of the scanner which is large and round like a doughnut; the scan itself takes about 10 minutes. For an MRI scan the table slides into a large metal tube that is open at both ends; the scan takes a little longer, about 30–90 minutes to perform. Both scans are painless.

PET (positron emission tomography) scan – before the scan you will be injected with a small amount of radioactive glucose (sugar) solution. Many cancer cells will show up brighter on the scan. You will be asked to sit quietly for 30–90 minutes to allow the glucose to move around your body, and the scan itself will take around 30 minutes to perform.

Ultrasound scan – soundwaves are used to create pictures of the inside of your body. For this scan, you will lie down and a gel will be spread over the affected part of your body. A small device called a transducer is moved over the area. It sends out soundwaves that echo when they hit something dense, like an organ or tumour. The images are then projected onto a computer screen. The ultrasound is painless and takes about 15 minutes.

Biopsy – removal of some tissue from the affected area for examination under a microscope. The biopsy may be done in different ways. In a core needle biopsy, a local anaesthetic is used to numb the area, then a thin needle is inserted into the tumour under ultrasound or CT guidance. A fine needle aspiration (FNA) may also be used, which collects cells using a smaller needle and usually doesn’t require an anaesthetic. A surgical biopsy is done under general anaesthesia. The surgeon will cut through the skin and take a tissue sample.