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Teratoma of Kidney

Last updated March 8, 2018

Approved by: Krish Tangella MD, MBA, FCAP

Teratoma of Kidney is a very rare, usually benign tumor, which arises from pluripotent cells. It consists of a variety of tissue types including epithelial cells, bone, cartilage, nerve cells, and skin. The tumor is mostly observed in children.

What are the other Names for this Condition? (Also known as/Synonyms)

  • Mature Cystic Renal Teratoma
  • Renal Teratoma

What is Teratoma of Kidney? (Definition/Background Information)

  • Teratoma of Kidney is a very rare, usually benign tumor, which arises from pluripotent cells. It consists of a variety of tissue types including epithelial cells, bone, cartilage, nerve cells, and skin. The tumor is mostly observed in children
  • In general, teratomas are tumors that arise from anywhere in the body. The most common locations include the ovaries, testes, sacrococcygeal region, brain, and mediastinum. A teratoma involving the kidney is extremely uncommon
  • The signs and symptoms of Teratoma of Kidney depend upon the size of the tumors and it may include blood in urine, abdominal pain, and frequent infections affecting the urinary tract system. Large tumors can potentially cause chronic kidney failure
  • Typically, a surgical excision of Teratoma of Kidney with its entire removal is the treatment of choice. The prognosis is excellent with its complete removal, since it is a benign tumor in most of the cases

There are 2 main subtypes of Renal Teratomas: 

  • Mature Teratoma of Kidney: It is made up of cells that resemble adult tissue cells. Most teratomas belong to the mature type
  • Immature Teratoma of Kidney: It is made up of cells that resemble an embryo, or developing fertilized egg

Who gets Teratoma of Kidney? (Age and Sex Distribution)

  • The Teratoma of Kidney are usually seen in infants and children. The tumor may also be present at birth (congenital Teratoma of Kidney)
  • It can also occur in a wide range of adults. The tumor has been recorded in adults aged 65 years too
  • Both males and females are affected and no predilection is noted
  • No specific ethnic or racial preference is seen

What are the Risk Factors for Teratoma of Kidney? (Predisposing Factors)

  • Currently, no definitive risk factors have been noted for Teratoma of Kidney
  • Very infrequently, the tumor has been associated with horseshoe kidney (a congenital disorder of the kidneys)

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one's chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Teratoma of Kidney? (Etiology)

The exact cause of Teratoma of Kidney formation is unknown.

  • In general, it is known that cancers form when normal, healthy cells begin transforming into abnormal cells - these cancer cells grow and divide uncontrollably (and lose their ability to die), resulting in the formation of a mass or a tumor.
  • The transformation of normally healthy cells into cancerous cells may be the result of genetic mutations. Mutations allow the cancer cells to grow and multiply uncontrollably to form new cancer cells
  • These tumors can invade nearby tissues and adjoining body organs, and even metastasize and spread to other regions of the body

What are the Signs and Symptoms of Teratoma of Kidney?

The signs and symptoms of Teratoma of Kidney depend on the size and location of the tumor. It can also vary from one individual to another. In general, small tumors are asymptomatic and large tumors can cause signs and symptoms. The kidney symptoms may be caused due to mass effect (presence of bulky tumors).

The signs and symptoms of Teratoma of Kidney may include the following:

  • The tumor may be present as an abdominal mass
  • It is often well-defined and demarcated
  • Some tumors can grow as large as 18 cm
  • It may be associated with urinary tract infections, blood in urine, increased blood pressure, and flank pain
  • Large tumors can severely affect the functioning of the kidney that is involved. Tumors growing to larger sizes can cause compression of adjoining organs and structures, but are not known infiltrate into them
  • Rarely, the tumors can affect both the kidneys

How is Teratoma of Kidney Diagnosed?

The diagnosis of Teratoma of Kidney may involve the following tests and procedures:

  • Complete physical exam with evaluation of medical history
  • Plain X-ray of the abdomen
  • CT or CAT scan with contrast of the abdomen may show a well-defined mass. This radiological procedure creates detailed 3-dimensional images of structures inside the body
  • MRI scans of the abdomen: Magnetic resonance imaging (MRI) uses a magnetic field to create high-quality pictures of certain parts of the body, such as tissues, muscles, nerves, and bones. These high-quality pictures may reveal the presence of the tumor
  • Ultrasound scan of the abdomen
  • Urine analysis to check for the presence of blood cells
  • Kidney function test
  • Intravenous pyelogram (IVP): A dye is injected into the blood vessels and the image of kidney structure is obtained
  • Vascular angiographic studies of the tumor

Invasive diagnostic procedures such as:

  • Laparoscopy: A special device is inserted through a small hole into the abdomen, to visually examine it. If necessary, a tissue sample is obtained for further analysis. Exploration of the abdomen using a laparoscope is called ‘exploratory laparoscopy’
  • Laparotomy: The abdomen is opened through an incision for examination, and if required, a biopsy sample obtained. Exploration of the abdomen using laparotomy procedure is called ‘exploratory laparotomy’

Although the above modalities can be used to make an initial diagnosis, a tissue biopsy of the tumor is necessary to make a definitive diagnosis to begin treatment. The tissue for diagnosis can be procured in multiple different ways which include:

  • Fine needle aspiration (FNA) biopsy of the kidney tumor: A FNA biopsy may not be helpful, because one may not be able to visualize the different morphological areas of the tumor. Hence, a FNA biopsy as a diagnostic tool has certain limitations, and an open surgical biopsy is preferred
  • Core biopsy of the kidney tumor
  • Open biopsy of the kidney tumor

Tissue biopsy:

  • A tissue biopsy of the tumor is performed and sent to a laboratory for a pathological examination. A pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis. Examination of the biopsy under a microscope by a pathologist is considered to be gold standard in arriving at a conclusive diagnosis
  • Biopsy specimens are studied initially using Hematoxylin and Eosin staining. The pathologist then decides on additional studies depending on the clinical situation
  • Sometimes, the pathologist may perform special studies, which may include immunohistochemical stains, molecular testing, and very rarely, electron microscopic studies to assist in the diagnosis

A differential diagnosis, to eliminate other tumor types is considered, before arriving at a conclusion. The differential diagnosis includes:

  • Teratoid nephroblastoma
  • Congenital mesoblasitc nephroma
  • Cystic nephroblastoma
  • Retroperitoneal teratoma involving the kidneys
  • Wilms tumor

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications for Teratoma of Kidney?

The complications of Teratoma of Kidney may include:

  • Stress and anxiety due to a concern of kidney cancer
  • Chronic renal failure affecting kidney function if tumors are large is a potential complication
  • Rarely, a teratoma has the potential for malignant transformation (malignant Renal Teratoma). Hence, long-term vigilance for any such transformation is necessary
  • Damage to the muscles, vital nerves, and blood vessels, during surgery
  • Post-surgical infection at the wound site is a potential complication

How is Teratoma of Kidney Treated?

The treatment measures for Teratoma of Kidney may involve surgical intervention with complete excision, which can result in a cure. This can also help reduce the chances of tumor recurrence.

The surgical treatment methods may include:

  • Endoscopic surgery
  • Nephron-sparing surgery
  • Partial or complete nephrectomy
  • Tumor embolization is a possible treatment option. Here the blood supply to the tumor is blocked resulting in its shrinkage or death

A partial or complete nephrectomy may be considered, when large-sized tumors are noted in the kidneys.

  • A kidney dialysis may be required, if the kidney function is severely compromised due to renal failure
  • Prompt diagnosis and emergency treatment of any abdominal (retroperitoneal) bleeding due to the tumor should be immediately considered
  • Postoperative care is important: A minimum activity level is ensured, until the surgical wound heals
  • Long-term follow-up care with regular screening may be recommended by the healthcare provider

How can Teratoma of Kidney be Prevented?

  • Current medical research has not established a method of preventing Teratoma of Kidney
  • Regular medical screening at periodic intervals with tests and physical examinations are strongly recommended

What is the Prognosis of Teratoma of Kidney? (Outcomes/Resolutions)

The prognosis of Teratoma of Kidney depends upon the severity of the signs and symptoms. It also depends upon the overall health of the individual and response to therapy.

  • Typically, in a majority of cases, the prognosis is excellent, since it is usually a benign tumor
  • In case of a malignant transformation, the prognosis may depend upon several factors including the stage of the tumor and health status of the individual

Additional and Relevant Useful Information for Teratoma of Kidney:

Please visit our Cancer & Benign Tumors Health Center for more physician-approved health information:


What are some Useful Resources for Additional Information?

References and Information Sources used for the Article:

Helpful Peer-Reviewed Medical Articles:

Reviewed and Approved by a member of the DoveMed Editorial Board
First uploaded: Sept. 8, 2017
Last updated: March 8, 2018