What is Cystic Teratoma?
Cystic teratoma is a type of tumor that originate from germ cells, which are cells that develop into various types of tissues in the body. Evidence of these tumors exists all the way back to 2000 years B.C. The first known case, recorded in 1659, described a young woman who died of an ovarian tumor that was identified as a cystic teratoma, also referred to as a “Dermoid cyst.” The term “teratoma” was introduced by Rudolf Virchow in 1863, and it originates from a Greek word meaning monster.
These types of tumors, found in the ovaries, are generally grouped into three categories: monodermal teratomas (which include certain types of tumors including carcinoid and neural tumors), immature teratomas, and mature cystic teratomas. The most common type is the mature cystic teratoma. About 20% of all ovarian germ cell tumors are cystic teratomas.
While these tumors are most often found in the ovaries or testes, they can also appear in other areas of the body such as the chest, tailbone area, or neck. These are typically harmless and grow slowly, at a rate of about 1.8 mm per year. However, in rare instances, they can become malignant, or cancerous.
What Causes Cystic Teratoma?
Research has found several factors that might increase the chance of developing mature cystic teratomas. These include having a late first period and irregular periods, a history of alcohol misuse, a previous cystic teratoma, having fewer children, problems getting pregnant, and exercising during teenage years, which might be linked to periods where no egg is released.
Risk Factors and Frequency for Cystic Teratoma
Cystic teratomas are a type of ovarian tumor that makes up 20% of all ovarian tumors in adults and half of all ovarian tumors in children. These tumors are typically not harmful, with only about 1% turning out to be malignant, or cancerous.
These tumors mainly affect women in their twenties and thirties and they are the most common benign tumor found in women under 45 years old. A study that included 460,000 females found that each year, 1.2 to 14.2 cases of cystic teratomas occur per 100,000 women.
Over the years, different studies have found different rates of incidence for these benign cystic teratomas. Some found an incidence rate as high as 20% of all ovarian tumors, while others reported rates as low as 5%. These varying numbers are due to the tumor’s rarity, with data often coming from either isolated case reports or small multicenter groups of cases.
- Cystic teratomas make up 20% of all ovarian tumors in adults and half of all ovarian tumors in children.
- They are often non-harmful, with only 1% being cancerous.
- They are most common in women in their twenties and thirties, being the most common benign tumor in women under 45.
- Each year, there are between 1.2 and 14.2 cases per 100,000 women.
- The incidence rate can vary, with some studies reporting rates as high as 20% of all ovarian tumors, while others report rates as low as 5%.
Signs and Symptoms of Cystic Teratoma
Cystic teratomas are a type of tumor that is often symptomless or causes only mild symptoms. Quite often, they are found by chance during a physical examination, while reviewing radiographic images, or during a surgical procedure for an unrelated issue. In fact, anywhere from 6% to 65% of these tumors are discovered this way. When symptoms do occur, the most common one reported is lower abdominal pain, affecting between 44-47% of patients, followed by feeling a distinct mass in the abdominal or pelvic area.
Some patients may notice that their belly size is increasing. Other symptoms such as digestive issues or urinary problems can arise as the tumor grows and begins to press on or invade nearby organs. Fever, extreme weight loss, severe abdominal pain, and vaginal bleeding can appear in more advanced cases.
One common complication of cystic teratoma is ovarian torsion, which can cause sudden stomach pain, nausea, and vomiting. This is a medical emergency that needs immediate attention. Doctors use a method called bimanual palpation of the ovaries to find out if a mass is present and to determine the size of the uterus. They will also check for any tenderness in the abdomen.
Because of this, getting a detailed history, particularly related to the patient’s gynecological history, and conducting a thorough physical examination of the abdomen and pelvis, are critical steps in diagnosing and managing a patient with these symptoms.
Testing for Cystic Teratoma
The first step when someone is suspected to have a mature cystic teratoma involves taking the patient’s vitals, collecting detailed medical history and performing an in-depth physical examination focusing primarily on the abdominal area and the pelvic region. They will then carry out a full blood count, checking for overall health, then a complete metabolic panel to assess organ function, and a pregnancy test if needed. These teratomas don’t have any unique markers, but testing for markers such as alpha-fetoprotein (AFP), human chorionic gonadotrophin (hCG), and lactate dehydrogenase (LDH) can help in diagnosis and tracking the condition over time.
Mature cystic teratomas are commonly symptom-free and can be found unexpectedly during examinations for other health issues. However, if a patient experiences abdominal pain, discomfort, and an increase in their belly size, imaging tests can provide valuable insights.
For imaging, ultrasound is generally the first choice when investigating an unusual growth in the adnexal region (ovaries or Fallopian tubes). A mature cystic teratoma appears as a mixed mass that sends back strong ultrasound waves due to the various substances it contains like calcifications, sebum, and hair. Other specific features of a teratoma are the so-called Rokitansky nodule, iceberg sign, dot-dash pattern (also known as dermoid mesh), and floating balls sign.
Moreover, when compared to abdominal ultrasound, transvaginal ultrasound is more effective in finding and characterizing cystic teratomas. This method has a high sensitivity (57.9%) and specificity (99.7%), making it as useful as MRI for this purpose. If the teratoma undergoes torsion, twisting, or cutting off its blood supply, this abnormality can also be spotted on a color Doppler ultrasound.
However, in some instances, an ovarian teratoma might be missed in an abdominal ultrasound as it may resemble bowel gas. If this is the case or for a thorough pre-operative assessment, doctors may opt for CT scans of the abdomen and pelvis.
Nevertheless, the most definitive way to diagnose a mature cystic teratoma is through histopathological evaluation, which studies the tumor under a microscope.
Treatment Options for Cystic Teratoma
Surgery is the best way to treat cystic teratoma, which usually affects women who can still have children. It’s important to consider the patient’s chance of having kids after treatment and minimize any complications that might happen after surgery. Things like the size of the cyst, ultrasound results, effects on neighboring body parts, chances of cancer, and – most importantly – the patient’s symptoms and desire to have children, should all be considered in creating a treatment plan. There are two main options:
Monitoring: Women who can still get pregnant and want to have babies, and who have a cyst smaller than 6cm, might be recommended to simply watch out for any change in the cyst. Doctors usually suggest this conservative type of treatment as long as the cyst doesn’t grow more than 2cm a year. Even if a woman is pregnant, doctors could suggest monitoring the condition if she doesn’t experience severe symptoms.
Surgical treatment: For women who can still get pregnant and who show symptoms of dermoid cysts that are smaller than 5cm, it’s typically better to remove only the cyst via laparoscopic cystectomy instead of taking out the entire ovary. For cysts larger than 5 to 6 cm, or those that take up the whole ovary and distort its structure, an oophorectomy or removal of the ovary might be needed. For women who already went through menopause and have multiple cysts, oophorectomy might also be recommended. Usually, a tissue sample from the surgery is examined to confirm the disease and to check if it’s malignant. In worse scenarios, a complete resection and further procedures might be needed. Laparoscopy is the best method for surgical treatment.
Laparoscopic surgery is useful as it also allows doctors to take a sample of peritoneal fluid and thoroughly check the abdominopelvic cavity for possible cancer, assessing any effects on nearby body parts. Laparotomy, a more invasive surgery, is usually only suggested for complex cases like large complex masses, ruptured cysts requiring immediate attention, or advanced-stage cancer. If there’s a high suspicion of cancer, the patient’s tissue sample is examined during surgery.
Laparotomy might be chosen over laparoscopy if there’s a risk of cyst content spillage. If pathology confirms it’s cancer, a complete excision of the tumor with staging determines further treatments. The chance of a cystic teratoma spilling during laparoscopic removal is low at 0.2%, but this can increase the chance of sticky tissues. Using an Endobag helps reduce the chances of spillage. Cystic teratoma might come back years after a laparoscopic cystectomy. Because of this, any remaining ovary should be carefully checked during surgery. Patients should be monitored for recurrence and other germ cell tumors after cystectomy.
What else can Cystic Teratoma be?
When doctors are diagnosing a cystic teratoma, which is a type of tumor, they have to consider a variety of conditions that it could possibly be, depending on where the mass is located and the details of its pathology. Therefore, the potential conditions are categorized based on whether they appear as a mass near the uterus or elsewhere.
Conditions not related to the uterus could be:
- Harmless: kidney cyst, peritoneal cyst, bladder diverticulum, pelvic kidney, peritoneal inclusion cyst, diverticular abscess, peritoneal or retroperitoneal abscess.
- Harmful: retroperitoneal sarcoma (a type of cancer), metastasis (where cancer cells have spread from their original site), and gastrointestinal cancer.
Conditions related to the uterus could be:
- Harmless: ectopic pregnancy, bleeding ovarian cyst, tubo-ovarian abscess, pedunculated fibroid (a type of non-cancerous growth in the uterus), polycystic ovary, simple cyst, endometrioma, cystadenoma.
- Harmful: endometrial carcinoma (a type of cancer), ovarian sarcoma, sex cord/stromal tumor, ovarian germ cell tumor, Kruckenberg tumor (a type of cancer).
What to expect with Cystic Teratoma
The likelihood of recovery greatly depends on the severity of the disease and any complications that may come with it. Simple cystic teratomas, a type of typically harmless tumor, usually have a very good chance of recovery after surgery. However, there is a small possibility that they might return within 2 to 10 years.
On the other hand, cystic teratomas that have become cancerous can have varying outcomes. These outcomes hinge on the stage of the tumor, how the tumor is growing, and whether it has spread to the blood vessels.
According to a study by Peterson and his team, people with tumors that hadn’t ruptured and were still in stage I had a 75% chance of living for at least five more years. Another pooled data study done by Kashimura and colleagues found that people with stage I tumors had a 50% five-year survival rate. For stage II, it fell to 25%, and for stage III, it dropped even further to 12%. Unfortunately, no one survived for five years with stage IV tumors.
Possible Complications When Diagnosed with Cystic Teratoma
Ovarian cystic teratomas, or ovarian tumors, can come with various complications. It’s vital to detect these early to avoid serious health impacts. Here are some common complications:
- Torsion: Ovarian tumors can twist around the ligament that supports them, disrupting blood flow. This could lead to gangrene or a blood-filled swelling. This twisting can occur in 3 to 21% of cases, with medium-sized teratomas at highest risk.
- Rupture: While not very common, ruptures can happen in 1 to 4% of ovarian teratomas. Rupture could leak fluids or other materials into the body, leading to inflammation, infections, or even expulsion of materials such as hair and teeth through the anus in extreme cases.
- Infection: The risk of infection in a cystic teratoma is approximately 1 to 4%. It can be caused by blood, lymph, or by a direct spread from nearby organs. Extreme cases of infection can also lead to rupture.
- Adhesions: Occasionally, a cyst may form a blood supply connection with surrounding tissues becoming “parasitic”. Persistent inflammation can worsen these adhesions, causing a risk of intestinal obstruction.
- Malignant transformation: A malignant transformation can occur in 1 to 3% of all cystic teratoma cases. The most common transformation is into squamous cell carcinoma, but other cancer types might also occur.
- Gliomatosis peritonei: This condition occurs when glial tissue attaches to the lining of the abdomen. Evaluating a tissue sample is needed for diagnosis because these grey or white nodules might look like other diseases.
- Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis: This rare autoimmune complication can result in neuropsychiatric symptoms. Early detection and treatment can improve the outcome.
Recovery from Cystic Teratoma
Less invasive surgeries, like laparoscopy, can lead to less pain after the operation, shorter hospital stays, and significantly less blood lost compared to a laparotomy. This results in quicker recovery and early mobilization. The patient’s recovery trajectory is also influenced by post-surgical advice about wound care, diet, pain control, and how much physical activity is acceptable.
Preventing Cystic Teratoma
When a patient starts showing signs or symptoms of a disease, doctors begin to guide and advise them. Before deciding on a treatment plan, it’s important to thoroughly explain the benefits and downsides of each option, as well as what they can expect in terms of outcomes and potential risks. For women who haven’t gone through menopause and want to have children in the future, the treatment approach is centered on preserving as much of the ovary as possible, minimizing the development of adhesions or scars, and encouraging regular check-ups.
