What are the pathological causes of secondary liver cancer? What you need to know about the pathological classification of the two major liver cancers

Secondary liver cancer is also called metastatic liver cancer. Malignant tumors throughout the human body can be transferred to the liver through the blood and lymph, or directly infiltrate to form secondary liver cancer. The clinical manifestations of secondary liver cancer generally only show the symptoms of the original organ cancer without the symptoms of severe liver involvement. Patients may have fatigue, anorexia, sweating, fever, weight loss and other symptoms. Liver function tests may still be normal even when the liver is obviously enlarged, but the detection of serum carcinoembryonic antigen is often significantly increased. B-ultrasound and CT examinations can detect liver space-occupying lesions. The prognosis of secondary liver cancer is generally related to the malignancy of the primary tumor, and the prognosis is poor. Comprehensive treatment such as surgery, radiotherapy and chemotherapy can be performed on the basis of the treatment of the primary tumor.

Cancers of many organs can metastasize to the liver, especially cancers of the abdominal organs such as stomach cancer, colon cancer, gallbladder cancer, pancreatic cancer, uterine cancer and ovarian cancer. In addition, cancers of the breast, lung, kidney, nasopharynx and other parts can also metastasize to the liver.

Symptoms and signs:

Secondary liver cancer often presents with symptoms caused by primary extrahepatic cancer. However, some patients still have difficulty finding their primary cancer after they have symptoms of secondary liver cancer, such as weight loss, fatigue, liver pain, liver nodules, or even ascites and jaundice. Therefore, it is sometimes difficult to distinguish it from primary liver cancer. Generally, the clinical manifestations of secondary liver cancer are often mild, and the course of the disease progresses slowly.

Causes of disease:

From the perspective of traditional Chinese medicine, the causes of liver cancer are mainly divided into the following five categories:

1. Emotional factors

It is believed that liver cancer is mostly caused by emotional changes such as emotional discomfort, mood swings, sadness and rage, which lead to poor qi and blood circulation, which in turn lead to dysfunction of internal organs and weakened resistance. It is induced by factors such as malnutrition, improper diet, cold and heat, excessive drinking, or invasion of external pathogens.

2. Invasion of external pathogens

It is believed that the cause of liver cancer is due to the retention of six evils such as dampness and heat in the meridians and gathering in the internal organs, resulting in qi stagnation and blood stasis, or qi and blood imbalance, or liver and kidney yang deficiency, which develops over time. Some scholars also believe that local cancer is caused by the gathering of heat, stagnation, blood stasis, phlegm and fluid under certain conditions. Its pathogenesis is "weakness caused by illness". That is, although patients may have symptoms of evil accumulation and qi and blood deficiency at the same time, the basis of its etiology and pathogenesis is the invasion of external evils.

3. Weakness of vital energy

It is believed that deficiency of vital energy is an important factor in the occurrence of tumors. Depending on the degree and stage of vital energy deficiency, there may be two types of situations: overt and covert. It is also caused by factors such as the six exogenous pathogens (hepatitis B, liver parasites), dietary disorders, internal injuries caused by the seven emotions, internal organ deficiency, and disharmony of qi and blood.

4. Combination of internal and external factors

The main internal factor is that liver cancer is a pathological product produced by the interaction of internal and external factors. The patient has both deficiency of the body and excess of evil, but deficiency of the body is the main one. The pathogenesis is a disease caused by the disease, with deficiency of the body and excess of the symptoms. Therefore, the clinical manifestations are systemic deficiency and local excess.

5. Differentiate etiology and pathogenesis according to the stage of disease

The early stage of liver cancer is related to dampness or mild qi stagnation, and the constitution is mainly spleen deficiency. In the middle stage, there are manifestations of qi stagnation, blood stasis, damp heat, and heat toxicity. In the late stage of liver cancer, yin deficiency and fluid deficiency are common. It is believed that liver cancer has the closest relationship with the spleen. The key to the pathological lesions of early liver cancer may be spleen deficiency, and in the late stage of liver cancer, there may be deficiency of liver, kidney and other organs.

In conclusion, the understanding of the etiology and pathogenesis of primary liver cancer has not yet been completely unified, and the above views are representative to a certain extent, and also reflect the multifactorial etiology and complex pathogenesis of liver cancer.

Pathophysiology:

The pathology of liver cancer is divided into: massive liver cancer, nodular liver cancer, diffuse liver cancer, etc. Below we introduce the pathological classification of liver cancer in detail:

1. Gross classification of liver cancer

(I) Massive type: more common, presenting as a single mass or a mass formed by the fusion of multiple nodules, mostly round in shape, with a diameter of more than 10 cm. It is hard and grows in an expansive manner. The liver tissue around the cancerous mass is often squeezed to form a pseudocapsule. This type is prone to liquefaction, necrosis and bleeding, so complications such as liver rupture and intra-abdominal bleeding often occur.

(ii) Nodular type, the most common, with cancer nodules of varying sizes and numbers, mostly in the right lobe of the liver, with less clear boundaries from the surrounding liver tissue than the massive type, often accompanied by cirrhosis. When the diameter of a cancer nodule or the sum of the diameters of two cancer nodules is ≤5 cm, it is called small liver cancer. It is characterized by a small size of the cancer mass, clear boundaries, expansive growth, capsule, and a lobed structure on the cross section. It grows relatively slowly.

(III) Diffuse type: the rarest type. Cancerous nodules ranging in size from rice grains to soybeans are scattered throughout the liver. The liver is not noticeably enlarged and may even shrink. Patients often die of liver failure.

2. Tissue typing

(I) The hepatocyte type is the most common. Cancer cells develop from hepatocytes and are arranged in polygonal nests or cords. There are abundant blood sinusoids between the nests or cords, but no interstitial components. Cancer cells have large nuclei, obvious nucleoli, abundant cytoplasm, and tend to grow into the blood sinusoids.

(ii) The cholangiocarcinoma type is less common. The cancer cells develop from the bile duct epithelial cells and are cubic or columnar, arranged in glandular shapes, with more fibrous tissue and fewer sinusoids.

(III) The mixed type is less common and has both hepatocellular carcinoma and cholangiocarcinoma structures, or presents an extreme morphology that is neither completely like hepatocellular carcinoma nor completely like cholangiocarcinoma.