An Overview of Gerota's Fascia

Gerota’s fascia, otherwise known as renal fascia, is collagen-filled, fibrous connective tissue that encapsulates the kidneys and adrenal glands. Gerota’s fascia separates perinephric fat from paranephric fat—the fat in the front and back of the kidney. Identifying Gerota's fascia is particularly important when it comes to radiographic testing such as ultrasounds and CT scans for finding abdominal masses, including kidney stones, abscesses (pockets of pus in the kidney that can often result from a UTI), or tumors.

Gerota's fascia is named for Dr. Dimitrie Gerota, a Romanian physician, radiologist, and urologist who studied the anatomy and physiology of the bladder and appendix in the 1900s. He is also responsible for the creation of the Gerota method, a technique used to inject lymphatic vessels.

What the Kidneys Do

In order to understand how Gerota’s fascia works with the kidneys and aids in kidney health, it’s important to understand what the kidneys do. The kidneys are responsible for removing waste from the body and extra water from the blood (which is excreted in the form of urine).

The kidneys help maintain overall fluid levels in the body, regulating minerals and chemicals, and with the adrenal glands create hormones that are responsible for producing red blood cells, regulating blood pressure, and promoting bone health.

Most people have two kidneys, but each kidney functions on its own, meaning that a person can live a healthy life with only one kidney.

Abdominal Masses

Locating an abdominal mass is a challenge for a radiologist, as depending on where the mass is in the abdomen, that coincides with what type of specialist will treat the mass.

Researchers have found that the shadows from Gerota’s fascia can be seen on radiographic tests because of the fat on either side of the kidney. When a mass is detected within the kidney, it pushes the shadow of Gerota’s fascia up, creating a triangle shape and alerting health professionals of an existing mass, which can then help steer additional testing and diagnosing. 

Kidney Cancer

Most kidney cancers start as carcinomas, which are cancer cells found in the lining of renal tubules. This is called renal cell carcinoma (RCC) and makes up about 90% kidney cancers.

The second most-common form is called transitional cell carcinoma (TCC), which is when cancer is found in the cells that line the renal pelvis. TCC makes up 5 to 10% of kidney cancers.

Two other types of kidney cancer, though rare, are renal sarcoma (which occurs in about 1% of kidney cancers) and Wilms tumor (occurring mostly in young children). As cancer cells grow to form new cancer cells, over time these cells can grow into other parts of the body, including tissue like Gerota’s fascia. When this happens, doctors classify the cancer as a stage 3, or T3, which is taken into consideration when discussing treatment options such as surgery, radiation, and chemotherapy.

Renal Cell Carcinoma

While cancer cells can spread to Gerota’s fascia, it can also help detect RCC before cancer cells can spread and grow in the body. By doing an ultrasound, doctors can use high-energy sound waves to bounce off of tissues like Gerota’s fascia to make echoes that produce a sonogram. This can then show if a tumor is forming in the small tubes of the kidneys, helping to pinpoint where the cancer is.

Gerota’s fascia can also be helpful in instances where a doctor decides to do a CT or CAT scan. By injecting dye into the body, tissues like Gerota’s fascia are able to absorb the dye to show up more clearly on the scan. The tumor doesn’t absorb the dye and will therefore appear as a dark mass on the scan instead. This is a particularly helpful technique to get an analysis of what's going on in the body without resorting to an invasive procedure.

Ectopic Kidneys

When one or both of the kidneys are in an abnormal position in the body, it’s called an ectopic kidney. This is a birth defect that happens when a kidney doesn’t climb up to its position near the rib cage and upper back during fetal development in the womb, getting stuck in the pelvis (called a pelvic kidney) or somewhere in between the pelvis and rib cage.

In severe instances, ectopic kidneys can become fused together. Problems resulting in an ectopic kidney include drainage issues, increased infections like UTIs or reoccurrence of kidney stones, and in some cases kidney failure.

Ectopic kidneys occur in one out of 3,000 people, researchers have found. Among those cases, there have been several studies to determine whether or not Gerota’s fascia is present in an ectopic or pelvic kidney (as the lack of one may contribute to its misplaced position as well as the reattachment of a partially attached Gerota’s fascia may help with kidney position and drainage).

A recent study published in the Indian Journal of Urology found that in a pool of 11 patients with ectopic and pelvic kidneys and different health issues associated with each, those who underwent surgery had evidence of Gerota’s fascia while those who only had a CT scan done of the kidneys did not. These findings lean more in favor of Gerota’s fascia being present in those with ectopic kidneys, but researchers say more testing and radiological studies are needed to give a definite answer to this.