Carcinoma of Unknown Primary

Diagnosis

Doctors at Mayo Clinic aim to locate where the cancer began so they can work with you to determine the most appropriate treatment. Diagnosis of carcinoma of unknown primary location begins with:

• A physical exam to check for lumps, swelling and areas of pain
• Questions about medical and family history, including past therapies and details about your symptoms
• Possibly, laboratory tests such as blood tests, urine analysis, tumor marker tests and stool evaluations, to establish where the cancer began
• A needle or simple surgery used to remove a small piece of your tumor (biopsy) for examination

Mayo Clinic doctors may use imaging studies to diagnose your carcinoma. These studies may include:

• CT scan. A CT scan creates two-dimensional images of your body that show how much the cancer has spread.
• Magnetic resonance imaging (MRI). Magnetic fields and radio waves create two- and three-dimensional views that show abnormalities in the body.
• PET scan. Radioactive materials help your doctor identify areas which may be cancerous.
• Ultrasound. High-frequency sound waves create images of your body to help your doctor identify cancer sites.
• X-rays. Radiation generates two-dimensional views of your body to help your doctor locate abnormalities.
• Other nuclear medicine scans. Your doctor may request bone and thyroid scans to define the locations where the tumor has spread.

Read more about CT scan, MRI, ultrasound and X-rays at MayoClinic.com.