What Is Leiomyosarcoma?

Leiomyosarcoma is a malignant mesenchymal tumor derived from intestinal smooth muscle, intestinal vascular smooth muscle, or intestinal mucosal muscle, accounting for 5% to 10% of all soft tissue tumors. Rectal leiomyosarcoma is most common, accounting for about 85% of colorectal leiomyosarcoma. The common location is the retroperitoneal area, which can be painful. Leiomyosarcoma that occurs in the inferior vena cava varies in symptoms depending on the location. In addition to local infiltration of adjacent organs and tissues, leiomyosarcoma is the most important metastatic pathway.

Basic Information

Visiting department

Oncology

Multiple groups

40 to 60 years old

Common locations

Retroperitoneum

Common causes

unclear

Common symptoms

The mass is located behind the peritoneum and is painful; it is located in the upper part of the inferior vena cava, with liver enlargement, jaundice, and peritoneal effusion; edema of the lower limbs, etc.

Causes of leiomyosarcoma

The cause of leiomyosarcoma is unknown.

Clinical manifestations of leiomyosarcoma

Soft tissue leiomyosarcoma often occurs in middle-aged and elderly patients, with a high incidence in the age group of 40 to 60 years. It can also occur in young people, and children are rare. It can occur retroperitoneally (the most common retroperitoneal malignancy), peripheral soft tissue (most commonly in the lower limbs, especially the thighs), or the walls of large blood vessels (mainly medium or large veins). The most common site is the retroperitoneal area, where tumors are larger and more common in women. In men, it usually occurs in the surrounding soft tissues and large blood vessels. Soft-tissue leiomyosarcoma often presents as a lump, which can be painful in the peritoneum. The symptoms of leiomyosarcoma of the inferior vena cava are related to the tumor site. Those who are located in the upper part of the inferior vena cava will block the hepatic vein, causing Budd-Chiari syndrome, which is manifested as hepatomegaly, jaundice, and peritoneal effusion; those in the middle of the inferior vena cava can block renal vein , Impaired renal function; occurs in the lower inferior vena cava and lower extremity large veins can cause lower extremity edema.

Leiomyosarcoma examination

Gastroscopy is often difficult to diagnose. X-ray barium meal, ultrasound gastroscopy, and CT can help diagnose leiomyosarcoma. B-mode ultrasound has a shallow position, large volume, and high detection rate of extra-cavity growth.

Leiomyosarcoma diagnosis

The imaging diagnosis of leiomyosarcoma is not characteristic, and the pathological diagnosis is mainly based on the morphological characteristics of the tumor under light microscopy and combined with immunohistochemistry to confirm the diagnosis. If the tumor does not have the morphological characteristics of this type of tumor, the diagnosis should not be based on the results of immunohistochemistry alone.

Leiomyosarcoma Treatment

The treatment of leiomyosarcoma is mainly surgical resection, including resection of tumor tissues, so that no tumor cells remain on the resection margin. Lymph node dissection is not recommended, and the affected lymph nodes should be resected together. Postoperative prevention should be proactive to prevent recurrence. Drugs of the BRM (biological response modifier) class are the best choice.

Prognosis of leiomyosarcoma

Soft tissue leiomyosarcoma can occur with local recurrence and distant metastasis, and lymph node metastasis is rare. Currently the most important prognostic factors are tumor location and size. Occurred in the retroperitoneum and larger tumors, the resection is difficult or the tumor cannot be completely resected, and local recurrence and metastasis are easy. Large vessel leiomyosarcoma has a poor prognosis. Local recurrences and metastases occur in the first few years after diagnosis and can also occur after 10 years. The most common metastatic sites of retroperitoneal leiomyosarcoma are the liver and lung, and non- retroperitoneal tumors mainly metastasize to the lung.