Tailgut cysts are rare congenital (present at birth) lesions. It is estimated that one in 40,000 births will have a tailgut cyst. They are typically found behind the anus-rectum junction. Based on their location, they can be grouped with other lesions as retrorectal (located behind the rectum) or presacral (located in front of the sacrum) lesions. Tailgut cysts are also referred to as retrorectal cystic hamartomas.

Although they are known to be congenital lesions, patients often receive a diagnosis in adulthood. They are observed three times more frequently in females than in males. The reason for diagnosis in later ages is twofold: some tailgut cysts remain asymptomatic, while in some patients, symptoms are not attributed to a tailgut cyst, leading to a lack of further investigation.

What are the symptoms of a tailgut cyst?

In nearly half of the patients with a tailgut cyst, there are no symptoms. They are often detected incidentally during radiological examinations conducted for other reasons. In other patients, symptoms may arise due to the pressure of the cyst on surrounding organs or due to infection. While originating from behind the rectum, as the cyst enlarges, it can exert pressure not only on the rectum but also on organs such as the vagina and bladder. A tailgut cyst can cause symptoms such as frequent urination and burning sensation during urination due to pressure on the bladder, as well as a sensation of fullness in the rectum, painful or difficult bowel movements, narrowing of the stool, and constipation due to pressure on the rectum. Because of its space-occupying nature in the retrorectal area, individuals may feel discomfort in the buttocks and coccyx region while sitting, and they may have difficulty sitting comfortably. When infection occurs in these cysts, it can manifest as a pelvic/anal abscess, painful swelling in the anal area, and in some cases, as a fistula.

How is a tailgut cyst diagnosed?

In patients presenting with specific complaints, suspicion of a tailgut cyst may arise during a rectal examination when a mass effect is felt externally behind the rectum, or during a gynecological examination when a cystic lesion is seen on ultrasound. However, the radiological diagnosis of a tailgut cyst is usually made with pelvic MRI. Although a cystic structure may be seen on computed tomography in some patients, MRI is often the preferred radiological diagnostic method for the complete characterization of the lesion. Biopsy of lesions suspected to be tailgut cysts is not recommended.

Does a tailgut cyst turn into cancer?

In the medical literature, malignant transformation on the basis of a tailgut cyst has been reported in many cases, but it is not known exactly how many of these cysts carry the risk of developing cancer. Delay in diagnosis or failure to perform adequate surgery is thought to increase the risk of cancer development.

What is the treatment for a tailgut cyst?

There is no medication for treatment. Surgical removal of the cyst is necessary. Surgically removing the cyst allows for a definitive diagnosis of the suspected disease, resolution of any symptoms the patient may have, and elimination of the risk of cancer development. Extensive surgical intervention is required for tailgut cysts that have developed cancer, similar to any cancer, while for cysts that have not developed cancer, simply removing the cyst is sufficient.

How is surgery for a tailgut cyst performed?

The surgical approach is determined based on the level of the cyst. For cysts located well above the pelvic muscles, an abdominal approach, either open or laparoscopic, may be preferred. If the cyst is located below the pelvic muscles or in an easily accessible area, a posterior (back) approach may be used. In some patients, surgery may need to be performed from both sides.

During the abdominal approach, the surgeon carefully separates the cyst from the rectum, sacrum bone, and, in some cases, the vagina or pelvic muscles, and removes it outside the abdomen in a sterile bag. Maximum care should be taken during this separation process to avoid damage to the rectum, vagina, and surrounding blood vessels. In case of any injury, effective repair should be performed.

In the posterior approach (Kraske approach), with the patient in a prone position, an incision is made through the skin and fatty tissues from the side of the sacrum bone and coccyx (tailbone). After cutting the anococcygeal ligament, the cyst is accessed. In some patients, the coccyx bone may need to be removed at this stage due to reasons such as the need to expand the working area or adhesions of the cyst. Once the cyst is exposed, it is completely removed without causing damage to the levator muscles or rectum and leaving no tissue behind. Depending on the size of the field, the nature of the tissues, and the surgeon’s preference, a drain may be placed in the surgical area. Subsequently, the layers are sutured layer by layer to conclude the operation.

In a combined approach, part of the surgery can be performed abdominally while the rest is done from the back, or vice versa, using the same principles and techniques.

Is surgery for a tailgut cyst risky?

Surgery for a non-malignant tailgut cyst, when performed by experienced hands, is not considered to carry significant risks. However, in cases where malignancy has developed, in patients who have previously had infections, or when surgery is performed by individuals lacking sufficient experience, complications such as rectal injury, vaginal injury, urinary tract injury, vascular injury, residual disease, or damage to the anal sphincter or pelvic muscles may occur. If these problems are not effectively addressed, long-term complications such as recurrence, fistula, or fecal incontinence may develop.

What is the cost of surgery for a tailgut cyst?

The cost of surgery is calculated based on factors such as the duration of the surgery, whether the patient has had previous interventions in the same area, whether the surgery is performed abdominally or posteriorly, and whether malignancy is present.

Recovery after surgery for a tailgut cyst

If the surgery is performed safely without any damage to the rectum or other surrounding organs, one night of hospitalization is usually sufficient. If repair of possible damage to surrounding organs is performed, the patient may need to be hospitalized for observation during the recovery period, which can extend up to 4-5 days. After complete recovery, patients can resume their normal activities without any issues.

Follow-up after surgery for a tailgut cyst

If there are no findings suggestive of malignancy in the cyst removed during surgery and sent for pathological examination, patients do not require any additional treatment. Since recurrence is not expected if the cyst is completely removed, no radiological or clinical examination/control is necessary. However, if the cyst is not completely removed, the surgeon may recommend periodic follow-ups based on the patient’s characteristics. There is no universally accepted follow-up algorithm for this purpose.

In liver ultrasound performed by an experienced radiologist accompanying the surgery, previously unseen additional lesions can be detected in up to 30% of patients. This is important for achieving thorough cleanliness.In addition to investigating additional lesions, ultrasound contributes significantly to confirming existing lesions, determining the boundaries of the lesion to ensure effective surgery, and reviewing the structures that need to be preserved during lesion removal.

Finally, in lesions where surgical removal is not appropriate, interventional radiologists can contribute to eliminating cancer by applying ablation (burning) techniques using radiofrequency or microwave techniques. While the lesion to be ablated is visualized with an ultrasound probe, the ablation needle is advanced into the lesion to perform the procedure. Liver ultrasound is essential for the application of the ablation technique.

Intraoperative ultrasound is mostly performed with the open method and can also be performed laparoscopically in centers with suitable infrastructure and sufficient experience. In the open surgical technique, after dissecting the liver’s surrounding structures, the liver is brought to the surface from deep using sterile towels. The interventional radiologist examines the liver tissue by placing the sterile-wrapped ultrasound probe directly on the liver. If necessary, they apply the ablation method under the same conditions.

In conclusion, it is recommended to perform liver ultrasound during surgery to increase the success of liver metastasectomy in all cases where it will be performed.

If the radiological examinations show that the cancer has adhered to surrounding organs, the treatment decision depends on the organ of origin and the tissue/organ involved. In some tumors, treatment may begin with chemotherapy and/or radiotherapy, followed by surgery after a certain period, while in others, the tumors are directly removed through surgery.

Before surgery, the surgeon must make a thorough radiological assessment to determine which organs will be removed along with the organ of origin. Additionally, during radiological examinations, the possibility of detecting adhesions during surgery should be considered, and both the patient and their relatives should be prepared for the possibility of additional organ removal.

At this point, one might wonder, “Isn’t it sufficient to remove the organ of origin of the cancer?”

As expected, the adhesion of cancer to surrounding organs may indicate that cancer cells have started to penetrate the adjacent organ. Leaving the organ adhered to by cancer in place while only removing the organ of origin may lead to the spread of cancer cells into the abdominal cavity and the progression of the disease.

Another question that may arise is, “Does the adhesion of cancerous tissue to surrounding organs necessarily occur due to the progression of cancer?”

We can approach this question in two ways. If it is clearly visible on tomography or MRI that cancer has entered the surrounding organ, there is no doubt in such cases. In this group, in patients who have the chance of being operated on, cancer cells in the removed surrounding organ can be seen in pathological examination.

On the other hand, in patients where there is suspicion of adhesion radiologically, or where it is clearly visible during surgery that cancer has not penetrated, the situation may be different. It is known that cancer cells can adhere to surrounding organs through an inflammatory reaction called desmoplastic reaction. This situation is particularly observed at a higher rate if an infection has developed within the tumor or in the remaining part of the organ connected to the tumor. If desmoplastic reaction is present in the patient, removing the surrounding organ may be unnecessary and may increase the risk of surgery. On the other hand, if there is adhesion due to the tumor but it is evaluated as desmoplastic reaction and the adhered organ is left in place, the tumor will remain in the abdominal cavity. It is often not possible to make this distinction.

In scientific studies on colorectal cancer, where it is assumed that every adhesion is due to cancer, and additional organs are removed and it is checked pathologically whether there is a tumor, it has been observed that adhesion due to the tumor occurs in up to 30% of cases. In other words, in cases where there is no obvious invasion, the removal of the adhered organ is unnecessary in 70% of cases. At this point, instead of focusing on the idea that removing the adhered organ will be unnecessary in 70% of cases, it is recommended to focus on the idea that if the organ is not removed, cancer cannot be completely removed in 30% of cases. That is, it is recommended to remove the adhered organ if there is doubt during surgery.

The organ to which the cancerous tissue is adhered must be removed as a whole (en bloc). For example, in a colon tumor adhered to the uterus, the colon and uterus must be removed together without separation to prevent tumor spread. Even if the surgeon first separates the colon and then completely removes the uterus and ovaries, the risk of recurrence will be very high because cancer cells will have spread.

It has been mentioned earlier that in tumors adhered to surrounding organs, oncological treatments or direct surgery can be initiated. At this stage, treatment approaches for cancers grown according to organs can be found below with examples.

In cases of gastric cancer, if the tumor has invaded the gastric wall and adhered to surrounding tissues, chemotherapy is initiated first regardless of which tissue it adhered to. After a certain period of chemotherapy, radiological evaluations are performed to check if the tumor has shrunk. If the desired degree of shrinkage has occurred and the adhered organ can be removed along with the tumor, the patient undergoes surgery.
If necessary, the spleen, tail or body of the pancreas can be removed in gastric cancer cases. In some patients, removal of the colon, diaphragm muscle, abdominal wall, liver tissue may also be required.

Similarly to gastric cancer, chemotherapy is initiated in cases of pancreatic cancer with cancer presence towards surrounding tissues. However, due to anatomical features, some patients with pancreatic cancer may be considered initially inoperable. In cases considered operable on the border, if sufficient shrinkage is seen after chemotherapy ± radiotherapy, surgery can be performed. In pancreatic cancer, cases may arise where the stomach, colon, or portal vein need to be removed.

In cases of colon cancer with adhesion to surrounding organs, surgery is often the first treatment option. Since the colon is in contact with a large area in the abdomen, it can invade many organs. Therefore, during interventions to eliminate colon cancer, organs such as the stomach, duodenum, small intestines, pancreas, gallbladder, liver, uterus, ovaries, bladder, and spleen may need to be removed. Although preoperative chemotherapy application for advanced colon cancers has been considered lately, it has not been widely accepted. As ongoing studies progress, the practice of starting with chemotherapy similar to stomach or pancreatic cancer may be highlighted. On the other hand, there are also studies recommending the evaluation of these patients with genetic analyses and starting immunotherapy if appropriate.

In cases of rectal cancer, when adhesion to surrounding organs is observed, it is a accepted approach to reduce the tumor by giving radiotherapy and, in some cases, chemotherapy. After treatments extended up to 6 months depending on the condition, the surgical approach is decided after radiological evaluation. Depending on the progression of rectal cancer in surrounding tissues, it is recommended to remove either the wall or the entirety of the organ to which it adhered. In rectal cancer, structures such as the prostate, seminal vesicles, bladder, coccyx or sacrum bone, vagina, uterus, and ovaries may need to be removed.

Depending on factors such as the patient’s body structure, the size of the tumor, and the surgeon’s experience, multi-organ removal surgeries can be performed openly, laparoscopically, or robotically.

In surgeries where multiple organs are removed, the duration of the operation is longer, there is more blood loss, and the need for intensive care is higher. The probability of complications during and after surgery may also be higher. Accordingly, the hospitalization period may be prolonged.

Despite all these negative situations, for effective oncological surgery, all tissues and organs in contact with cancer must be removed with clean surgical margins in patients where it is deemed necessary.