Retroperitoneal Tumors - Causes, Types, and Treatment

Introduction:

The peritoneum is a tissue that covers the belly or abdomen and most organs in the abdomen. The stomach is the part present between the chest and the pelvic region. The lesions that grow behind the peritoneum and the abdominal wall are called retroperitoneal tumors. It causes symptoms like unexplained weight loss, loss of appetite, pain in the abdominal region, and blood in the stools. Imaging techniques like ultrasound abdomen, CT (computed tomography) scan, and MRI (magnetic resonance imaging) scan techniques are used to find the disease. Then, retroperitoneal tumors are surgically resected.

What Is Retroperitoneum?

The retroperitoneum is a space present between the peritoneum in the front and behind the abdomen (belly region). The 12th rib is above and below the base of the sacrum and iliac crest (a part of the pelvis bone). The sides are bordered by the quadratus lumborum muscle (the back muscle that is present deep inside). This space consists of organs like kidneys, ureters, adrenal glands, aorta (a major blood vessel that carries blood from the heart to other body parts), and its branches and tributaries.

What Causes Retroperitoneal Tumors?

The causes of retroperitoneal tumors are unclear, but they develop from the mesodermal cells of any tissues from the retroperitoneal space. Mesodermal cells arise from the mesoderm, which is responsible for making essential structures and organs like skin, heart, muscles, bones, bone marrow, and the urogenital system. In addition, genetic causes like gene mutations cause a few types of retroperitoneal tumors.

What Are the Types of Retroperitoneal Tumors?

Retroperitoneal tumors can be malignant (cancerous and tends to spread to other organs) and benign (noncancerous that do not spread). Malignant tumors are three fourth times more common than benign lesions. The lesions can be further divided into cystic and solid lesions depending on the content of the lesion. A cystic lesion is a fluid-filled sac, and a solid lesion consists of tissues, immune cells, cancer cells, and other cell types.

• Benign Tumors:

  • Schwannomas.

  • Neurofibroma.

  • Ganglioneuroma.

  • Lipomas.

• Malignant Tumors:

  • Lymphoma.

  • Liposarcoma.

  • Leiomyosarcoma.

  • Malignant fibrous histiocytoma.

  • Desmoid tumors.

  • Extragonadal germ cell tumor.

  • Metastatic retroperitoneal lymphadenopathy.

• Solid Tumors:

  • Liposarcoma or Lipoma: Cancers that arise in the body's fat cells, mainly in the leg muscles or belly region.

  • Leiomyoma or Leiomyosarcoma: Cancer growth in the smooth muscles. Smooth muscles like organs like intestines, bladder, stomach, blood vessels, and uterus. It is a rare type of cancer.

  • Fibroma or Fibrosarcoma or Malignant Histiocytoma: A rare type of cancer growth in the soft tissues like tendons (a flexible and strong rope-like structure that connects the bone and muscles), ligaments (a band of elastic tissue that connects two bones), and muscles.

  • Desmoid Tumor: A noncancerous connective tissue growth. It is commonly seen in the legs, hands, and stomach region.

  • Ganglioneuroma or Ganglioneuroblastoma: Autonomic nervous system controls a few body functions like blood pressure, heart rate, sweating, digestion, and bowel movements like emptying the bowel and the bladder. Abnormal tissue growth in the autonomic nerve cells causes ganglioneuroma and is usually noncancerous.

  • Schwannoma or Neurofibroma: An abnormal growth in the nerves that can be seen as smooth bumps on the skin. It can appear on both major and minor nerves.

  • Extragonadal Germ Cell Tumor: A growth that happens due to the developing sperm or egg cells that transport from gonads to other body parts. Chest pain and breathing difficulty are the symptoms of this condition.

  • Lymphoma: Abnormal tissue growth in the lymphatic system. The two main lymphoma types are Hodgkin's and non-Hodgkin's.

  • Metastatic Retroperitoneal Lymphadenopathy: Cancer spreads to other organs through the lymph nodes. It happens mainly in cancers of the pelvis and abdomen.

• Cystic Tumors:

  • Cystic Lymphangioma: A rare noncancerous lymphatic system malformation that consists of abnormal masses of lymphatic channels. It occurs in 1 of 2000 to 4000 babies during birth.

  • Cystic Teratoma: Cystic teratoma is a commonly noticed ovarian neoplasm. Neoplasm is an abnormal mass that occurs when the cells divide and grow uncontrollably, and these cells do not get destroyed at the right time.

  • Cystadenoma or Cystadenocarcinoma: It is a noncancerous epithelial neoplasm that is cystic. This neoplasm consists of epithelium-lined projections that protrude into cystic spaces.

  • Cystic Mesothelioma: It is a lesion that contains abnormally growing cells of the peritoneal mesothelial cells. It is a rare disease seen in the pelvic and abdominal regions.

  • Epidermoid Cyst: It is a tiny noncancerous bulge seen under the skin, mainly in the face, neck, and trunk (consists of the chest, belly region, pelvis, and back). It can also appear on any skin surface.

  • Tarlov Cyst (Perineural Cyst): Tarlov cyst is a fluid-filled pocket that forms in and around the nerve roots. They appear in any part of the spine but are common in the sacral region (bottom of the spine).

What Are the Symptoms of Retroperitoneal Tumor?

The symptoms appear when the tumor grows big.

• Pain in the abdominal region.

• Abdominal distension (outward swelling of the belly).

• Mass in the belly region.

• Weight loss.

• Loss of appetite.

• Blood in stools.

How Are Retroperitoneal Tumors Found?

• Ultrasound Abdomen: Ultrasound imaging uses a high-frequency sound wave to capture images of the targeted organ. It shows if the cystic lesion is present or not.

• CT Scan Abdomen: Computed tomography is an imaging technique that uses X-ray radiations to capture images of the targeted structure on a computer screen. It gives a detailed view of the organ, and any abnormality detected.

• CT Scan Guided Biopsy: A radiologist performs the biopsy with a (computed tomography) CT scan as guidance. The tissue sample is obtained from the organ by inserting a needle deep into the structure-guided through a CT scan. It confirms the type of lesion.

• MRI Scan Abdomen: Magnetic resonance imaging (MRI) technique uses a combination of radio waves generated by a computer in a high-frequency magnetic field to take images of the target organs and structures surrounding them. It gives a detailed view of organs, tissues, and any abnormality detected in the organ.

How Is Retroperitoneal Tumor Treated?

• Surgical Resection: Complete surgical resection of the lesion along with the layer of the organ or tissue it resides on is removed completely. It is the first choice of treatment for retroperitoneal tumors.

• Chemotherapy: An anti-cancer medication is administered to damage and kill cancer cells. Doxorubicin and Ifosfamide are chemotherapeutic medications that are used to treat symptomatic sarcomas.

• Conventional Radiotherapy: High-energy rays like X-rays and gamma rays are targeted at the cancerous cells, and they shrink and destroy the cells. It reduces the lesion size for further treatments like surgery or radiotherapy.

What Is the Prognosis of Retroperitoneal Tumors?

Benign tumors do not cause death, and the prognosis after surgical resection is good. However, the malignant tumors have a poor prognosis with a 36 to 58 percent 5-year survival rate.

Conclusion:

The retroperitoneal tumors are benign (noncancerous) and malignant (cancerous). It mainly arises from the retroperitoneal spaces rather than the retroperitoneal organs. It usually is asymptomatic. If the lesion grows and presses the neighboring structures, symptoms like stomach pain and abnormal stomach swelling are seen. The lesions are generally found with clinical signs and imaging techniques, and the treatment is planned accordingly. Surgical resection is the first choice of treatment for both benign and malignant tumors. However, the survival rate is very poor if the cancer is spread to many other organs. Though these lesions grow big in a short period, the patient should visit the doctor as soon as the symptoms start occurring. Appropriate treatment will prevent complications and prolong the patient's lifespan.