What Is a Retroperitoneal Tumor?

Retroperitoneal tumors mainly include primary retroperitoneal tumors that originate in the potential space behind the peritoneum, and secondary retroperitoneal tumors that have metastasized from other sites. Clinically, retroperitoneal tumors are usually only referred to as primary retroperitoneal tumors, most of which belong to soft tissue tumors, accounting for 15% of the latter. Primary retroperitoneal tumors are relatively rare clinically, accounting for less than 1% of malignant tumors. Malignant tumors account for 80% of retroperitoneal tumors, and the most common are sarcomas derived from mesenchymal tissue, accounting for 42%. According to statistics from the National Institutes of Health (NIH) SEER database, the number of new cases of retroperitoneal sarcoma in China each year should be about 10,000.

Basic Information

English name

retroperitoneal neoplasms

Visiting department

General surgery

Common locations

Retroperitoneum

Common causes

Fat from the retroperitoneal space, loose connective tissue, fascia, muscle, blood vessels, nerves, lymphoid tissue, and embryonic residual tissue

Common symptoms

Abdomen fullness and mass; abdominal distension and nausea and vomiting due to compression of the intestine; tumor necrosis, bleeding with fever, inability to eat resulting in weight loss or cachexia

Causes of retroperitoneal tumors

It is mainly derived from fat in the retroperitoneal space, loose connective tissue, fascia, muscle, blood vessels, nerves, lymphatic tissue and embryonic residual tissue.

Retroperitoneal tumor tumor type

Liposarcomas are the most common soft tissue tumors that occur behind the peritoneum, followed by leiomyosarcoma. Other common tumor types include pleomorphic undifferentiated sarcoma (formerly known as malignant fibrous histiocytoma) and paraganglioma (pheochromocytoma). ) And malignant mesothelioma. Although the incidence of retroperitoneal tumors is low, it covers dozens of tumors with different histological types and different biological behaviors. In addition, the special anatomical structure and huge tumor body have raised higher academic and technical requirements for the formulation and implementation of related treatment decisions. The requirements also put forward higher requirements for relevant medical institutions in terms of clinical teams and scientific research in terms of expert teams, equipment, and diagnosis and treatment models. In order to ensure medical quality and safety, it is recommended that patients go to large-scale clinics with experience. Since the diagnosis and treatment of secondary retroperitoneal tumors need to refer to the situation of the primary lesion, they cannot be described one by one here.

Clinical manifestations of retroperitoneal tumors

Due to the deep location of the retroperitoneal tumor, usually there are no obvious symptoms and signs in the early stage. When the patient feels the abdomen full or touches the abdominal mass, the mass is often huge. Due to the lack of specific clinical manifestations of retroperitoneal tumors, they are rarely detected early.

In the later stages, the clinical symptoms exhibited by the patient are not typical. For example, obstruction of the gastrointestinal tract caused by compression of the intestinal tract, causing abdominal distension and nausea and vomiting, or fever caused by tumor necrosis and bleeding, and wasting or cachexia caused by the patient's inability to eat, and the late manifestations of other malignant tumors No essential difference. Only a few functional tumors secrete some hormones, which can affect blood pressure or blood sugar.

Retroperitoneal tumor examination

Laboratory inspection

Because retroperitoneal tumors are mostly derived from mesenchymal tissue rather than epithelial, even malignant tumors rarely cause the rise of common epithelial tumor markers (such as carcinoembryonic antigen), and clinically lack specific tumor indicators. . A small number of neuroendocrine-derived tumors can cause some markers to increase (such as neuroblastoma expressing neuron-specific enolase NeuronSpecificEnolase, NSE, etc.), but its accuracy is still insufficient. In addition, some functional retroperitoneal tumors can cause changes in biochemistry and some hormone levels.

2. Imaging examination

The imaging of retroperitoneal tumors is the main basis for its diagnosis. Although ultrasound is one of the easiest and most economical examination methods, because the location of the retroperitoneal tumor is deep, the gas in front usually interferes with the ultrasound. Therefore, for CT imaging of retroperitoneal tumors, enhanced CT or MRI is preferred. Due to the variety of pathological types of retroperitoneal tumors, the texture of the tumors is quite different, and even the same tumors show significantly different heterogeneity, so the performance of CT or MRI is not consistent.

Retroperitoneal tumors lack specific qualitative imaging signs, and qualitative diagnosis has certain difficulties. The following signs are often suggested as malignant lesions: Invasion of tumor adjacent tissues and blood vessels and distant organs and lymph node metastases are found. The edges of the tumor are irregular, and the boundary between the tumor and the surrounding organs is not clear. The abnormal density of the contact surface between the surrounding organs and the tumor appears, suggesting that adjacent organs are involved and the possibility of malignant tumors is high. Direct tumor invasion caused bone destruction or metastasis in other parts. CT and MRI showed uneven enhancement of tumor, showing abundant blood supply, mostly malignant tumor.

3. Pathological examination

There are various types of retroperitoneal tumors with different prognosis, but most of them require surgery, and fewer tumors are effective for radiotherapy and chemotherapy. Therefore, unless surgical resection is not possible, and further pathological properties need to be clarified in order to take more targeted treatment, consideration should be given to biopsy pathology. Biopsy usually advocates using a core needle to obtain sufficient tissue samples for pathological and immunohistochemical analysis, and even genetic testing to determine whether there is a suitable targeted therapy.

Diagnosis of retroperitoneal tumors

Although it is difficult to diagnose a retroperitoneal tumor solely on the basis of clinical symptoms and signs, it is not difficult to make a local diagnosis based on enhanced CT or MRI due to the large tumor mass. A qualitative diagnosis that further determines prognosis is difficult to judge by preoperative clinical and imaging manifestations. Pathological diagnosis as the gold standard is often obtained after surgery or puncture, and the next treatment strategy is developed accordingly.

Retroperitoneal tumor treatment

Surgical treatment

The surgical treatment of retroperitoneal tumors is mainly surgical resection, which is the best way for patients to obtain potential healing opportunities. The principle of surgical resection is to perform a standardized radical resection (R0 resection) as far as possible under the premise of ensuring safety. In recent years, with the improvement of understanding, more scholars have advocated Compartment Resection for retroperitoneal malignant tumors in order to achieve better curative effect. It is reported in the literature that the use of this more extensive resection can reduce the 5-year recurrence rate after resection from 50% to 20%, and the 5-year survival rate can reach more than 70%.

Retroperitoneal tumors are prone to repeated local recurrences. Patients often undergo multiple surgeries, and the interval between relapses is gradually shortened, until surgery can no longer be performed. Therefore, in addition to paying attention to the radical nature of the first operation, patients also need to find the right time for surgery when recurrence occurs.

(1) Severe complications such as bleeding and obstruction require surgery, and even palliative resection may be considered to save lives;

(2) Those who are close to important organs and whose tumors continue to grow will lead to unresectable or severe consequences;

(3) When the tumor has poor biological behavior, high malignancy, short relapse interval, and fast growth rate (such as more than 0.9 cm / month), surgical treatment often cannot change the final survival time, and surgical intervention is not appropriate.

2. Radiation therapy

Preoperative, intraoperative, and even postoperative radiotherapy, although showing some prospects, are far from reaching consensus. With the continuous development of radiotherapy equipment and technology, especially the application of Intensity Modulated Radiation Therapy (IMRT) and Stereotacticbodyradiotherapy (SBRT), retroperitoneal tumors located in the body and surrounding with many important organs have been developed More precise treatment of the target area, which improves the efficacy and reduces tissue damage.

3. Interventional Therapy

Intervention can not only help to understand the blood supply of tumors before surgery, but also for the treatment of retroperitoneal tumors with abundant arterial blood supply and large tumors, selective blood supply arterial embolization can be used to reduce the risk of intraoperative bleeding or promote the establishment of collateral circulation. , Reduce the impact of removal of the tumor on hemodynamics, thereby reducing the risk of surgery. When the retroperitoneal tumor ruptures and bleeds, and urgent hemostasis is needed, but surgery cannot be performed, interventional embolization or balloon occlusion of tumor blood vessels can be tried to gain time and create conditions for further treatment.

4. Systemic treatment

With the exception of lymphomas, a few retroperitoneal tumors are sensitive to chemotherapy, and most retroperitoneal tumors do not yet have significant chemotherapeutic drugs. Although doxorubicin, dacarbazine, and gemcitabine have shown some application prospects, large-scale clinical trials are still needed.

The new generation of targeted drugs represented by sunitinib has also achieved promising results in the treatment of retroperitoneal tumors. However, due to the high price, the burden on patients is heavier. Molecular typing of tumors based on genetic testing provides a theoretical basis for precision medicine for complex retroperitoneal tumors. Finding suitable targeted drugs through genetic testing of tissues or blood will increase the efficacy of tumor treatment and reduce unnecessary economic burden.

5. Multidisciplinary team consultation (MDT)

Due to the particularity of retroperitoneal tumors in biological characteristics and pathological types, the role of multidisciplinary collaboration is particularly important. In the process of diagnosis and treatment, a multidisciplinary team of surgical, internal medicine, radiotherapy, intervention, imaging and scientific research personnel form a diagnosis and treatment team, discuss related cases together, and plan the individualized treatment plan that is most suitable for the patient, so that the patient can get the most Reasonable treatment.

In short, the incidence of retroperitoneal tumors is small, the pathological type is complicated, the treatment is difficult, and the cooperation of multiple disciplines is required. Therefore, it is recommended that patients go to an experienced large-scale diagnosis and treatment center for standardized treatment to improve the treatment effect.