Overview of Hepatosarcoma
Hepatic sarcoma, also known as malignant mesenchymal tissue tumor of the liver, is a rare malignant tumor originating from the mesenchymal tissues of the liver, which mainly includes hepatic hemangiosarcoma and other primary hepatic sarcomas from mesenchymal tissues, such as hepatic fibrosarcoma, hepatic rhabdomyosarcoma, and hepatic liposarcoma, etc, of which hepatic hemangiosarcoma is the most common. The disease is prevalent in males and is more common in children and the elderly.
Causes
It is mainly related to long-term exposure to chemical substances (such as thorium dioxide, vinyl chloride, arsenic, etc.), endogenous radiation exposure and hemochromatosis, while the etiology of other hepatic sarcomas is unknown.
Symptoms
In the early stage, there are mostly no special symptoms and signs, and patients often consult the doctor because of the discovery of an epigastric mass. With the progression of the disease, liver pain, fatigue, nausea, vomiting, lack of appetite, weight loss, epigastric mass and digestive symptoms may appear. Jaundice, ascites and malignancy may be present in advanced stages. Larger hepatic hemangiosarcoma may rupture and bleed; hepatic rhabdomyosarcoma may present with intermittent obstructive jaundice and fever in the early stage. There are often extrahepatic metastases, mostly hematogenous, to lung, pancreas, spleen, kidney and adrenal gland, etc. Lung metastases are most common.
Examination
1. Laboratory examination
Radioimmunoassay: persistent serum alpha-fetoprotein (AFP) ≥ 400 μg / L. Total leukocyte count is increased or decreased, thrombocytopenia. Most patients have abnormal liver function. Sodium sulfobromophthalein test may be positive, alkaline phosphatase is elevated, prolongation of prothrombin time, blood bilirubin, alanine aminotransferase is elevated.
2. Imaging examination
(1) Ultrasonography: it can show the size, shape and location of the tumor, and whether there is cancer thrombus in the hepatic vein or portal vein, and its diagnostic conformity rate can reach 90%, which is a non-invasive examination method with good diagnostic value.
(2) CT examination: CT has high resolution and can detect tiny cancer foci with a diameter of about 1.0cm. ①Hepatic angiosarcoma is often multiple, with low density, and the density is consistent with that of large blood vessels, and the enhancement scan can show obvious enhancement at the edge or center of the lesion in the arterial phase, and the enhancement spreads to the surrounding area with the prolongation of time until it becomes isodense. Hepatic liposarcoma can be seen as a characteristic sign of fat-dense tissue. (iii) Hepatic fibrosarcoma, hepatic rhabdomyosarcoma is mostly manifested as a huge low-density mass in the liver, accompanied by irregular necrosis or hemorrhage, with moderate enhancement of the parenchymal portion of the enhancement scan, and thicker tumor blood vessels can be seen.
(3) Magnetic resonance imaging (MRI): the diagnostic value is similar to that of CT, and it is better than CT in distinguishing benign and malignant intrahepatic space-occupying lesions, especially with hemangioma.
(4) Selective abdominal artery or hepatic artery angiography: for cancers with abundant blood vessels, the resolution is limited to about 1 cm, which is a traumatic examination and should be considered only when necessary.
(5) Hepatic aspiration cytology: fine needle aspiration under the guidance of ultrasound can help improve the positive rate. It is suitable for those who cannot be diagnosed after various examinations but are highly suspicious.
3.Histopathologic examination
(1) Hepatic hemangiosarcoma: derived from malignant hepatic blood sinusoidal endothelial cells, with different morphology, most of them are honeycomb hemorrhagic nodules with unclear boundary and soft texture. Under the light microscope, the tumor cells grow infiltratively along the hepatic blood sinusoid, which can be sinusoidal gap-like, spongy, nodular papillary and solid spindle-shaped cell clusters. Epithelioid hemangioendothelioma is a kind of slow-growing low-grade malignant tumor, and the tumor tissue is characterized by hypertrophied epithelioid cells and elongated cells, hardened dense fibrous tissue and mucus-like stroma.
(2) Hepatic smooth muscle sarcoma: slow-growing, cell-rich, microscopic manifestation of consistent size of the spindle-shaped cells, the nucleus is blunt at both ends, Masson staining cytoplasm red staining, can be seen in varying amounts of nuclear schizophrenia, some areas of the tumor can be seen giant cells.
(3) Hepatic fibrosarcoma: it is a malignant tumor of fibroblast origin, with large differences in morphology. Under the microscope, the spindle-shaped tumor cells were arranged in bundles and there were a large number of collagen fibers deposited.
(4) Hepatic lymphoma: a malignant tumor limited to the liver without lymph node or extrahepatic spread and with lymphocyte sign. The most common microscopic type is large cell lymphoma.
(5) Hepatic osteosarcoma: microscopically, it is characterized by extensive bone-like tissue formation within the tumor tissue, surrounded by sarcomatoid mesenchyme with multinucleated tumor giant cells.
(6) Hepatic rhabdomyosarcoma: it is often a large grapelike mass with bold polypoid masses in the ducts, and rhabdomyoblasts can be seen microscopically.
(7) Hepatic neurosarcoma: the mass is often secondary to hemorrhage and necrosis, the section is colorful, the hemorrhagic necrotic area is purple or reddish-purple, the gel-like tumor area is grayish-white, and the scattered spindle cells can be seen under the microscope.
Diagnosis
1. This disease should be considered when liver occupying lesion is found and grows rapidly, and when hepatic hemangioma is suspected by imaging examination.
2. The diagnosis of hepatocellular carcinoma can be considered when continuous serum alpha-fetoprotein ≥400μg/L is determined by radioimmunoassay and pregnancy and active liver disease can be excluded.
3. Histopathologic examination is decisive for the diagnosis of this disease.
Treatment
Surgical resection is the mainstay, but the rate of radical resection is low, and the efficacy of radiotherapy or chemotherapy is unsatisfactory. Interventional therapy and hepatic artery ligation can sometimes control the disease. Hepatic epithelioid hemangioendothelioma and hepatic Kaposi’s sarcoma are mainly treated with radiotherapy.
Prognosis
The disease is highly malignant, with rapid disease progression, most of which are found in advanced stage, low surgical resection rate, and poor overall prognosis. Most untreated patients die within 6 to 12 months, and the cause of death is usually liver failure or intra-abdominal hemorrhage.