This is the second part of our series about the condition based on our patient booklet “Fast Facts for Patients and their Supporters: Advanced Cutaneous Squamous Cell Carcinoma”. This article explains how cutaneous squamous cell carcinoma can be diagnosed.

What Is a Biopsy?

A biopsy is a procedure to remove a sample of tissue from an area. The sample will be sent to a laboratory to get more information about the types of cell in the sample – for example, a pathologist can look at them under the microscope to see what types of cell are involved. Often, samples of lymph nodes are also taken. Lymph nodes are important collection sites for cancer cells. They can be the first place to show signs that the cancer is spreading.

Taking a Skin Biopsy for Diagnosis

A primary cutaneous squamous cell carcinoma (cSCC) usually appears as a new lump or sore on the skin and is diagnosed by a skin biopsy. This is a minor procedure carried out in your doctor’s office, often at the same appointment as your skin check. The doctor will clean the skin and inject a small amount of local anesthetic to numb it. A sample of the growth is removed, and the doctor will either put in a few stitches or allow the area to heal without stitches. In most cases, the biopsy is enough to make the diagnosis and plan treatment, which is normally surgery. In this case, no other tests are necessary.

Additional Biopsies That May Be Performed

Needle Biopsy

If you or your doctor feels a deeper lump under your skin, or if your imaging shows a suspicious lump in one of your lymph nodes, a needle biopsy or fine needle aspiration can be used to take a sample from the area. The doctor will clean the skin and inject a small amount of anesthetic to numb it. If the lump is difficult to feel, he or she might use ultrasound to help find it. A needle is put into the skin to collect a sample of cells from the lump. This may be repeated several times. Once the biopsy is complete, it will be sent to the laboratory. Ask your doctor when you can expect to hear the results.

Sentinel Lymph Node Biopsy

Sentinel lymph node biopsy is used to see whether your cSCC has spread into your lymphatic system – the sentinel nodes are the first lymph nodes that would be affected if your cancer is spreading. To identify the sentinel lymph nodes, a radioactive tracer, a blue dye or both will be injected into the area of the primary cSCC. The radioactive tracer is injected a few hours or a day before surgery. The blue dye is usually injected during surgery. The dye or tracer travels through the lymphatic system to the nearby lymph nodes. Your surgeon will detect the tracer from its radioactivity, while the dye will turn the lymph nodes blue. Once the sentinel lymph nodes have been identified, one or more will be removed and sent to the laboratory to look for tumor cells. The risks of this procedure depend on the position of your cancer and the lymph nodes. Talk to your surgeon about what it might mean for you.

Other Types of Tests

Previously we have looked at how a biopsy can help confirm a diagnosis. But other tests are sometimes helpful for advanced cSCC. These are the work up or staging tests, and they can help with planning surgery. Or they may be recommended after surgery to see if more treatment is needed.

Imaging (Scans)

The type of imaging you have depends on your individual cancer. Some people don’t need it.

Computerized Tomography (CT) Scan

A CT scan (or sometimes “cat scan”) involves taking a series of X-rays to give a cross-sectional picture of the body. CT scans are used to see if cSCC has spread to lymph nodes or has grown into the bone.

Magnetic Resonance Imaging (MRI)

MRI builds up a picture of an area using a magnetic field. Like CT, it gives a cross-sectional picture.

Positron Emission Tomography (PET) Scan

Before a PET scan, a radioactive tracer is delivered into a blood vessel. The tracer spreads through the body, building up at places where cancer cells are present. This is detected by the scanner. PET scans are used to see if the cancer has spread. Often a person has a PET scan and CT scan or MRI.

Ultrasound

Ultrasound uses high-frequency sound waves. It’s used to see if cancer has spread to the lymph nodes or to check lymph nodes after surgery.

Please check out the first post of our series here:

• What Is (Advanced) Cutaneous Squamous Cell Carcinoma?

Information based on Fast Facts for Patients and their Supporters: Advanced Cutaneous Squamous Cell Carcinoma (Karger, 2020).