Overview of liver carcinoid tumor
Hepatic carcinoid is a carcinoid tumor originating in the liver, which is an extremely rare slow-growing epithelial cell tumor with malignant tendency, and only a few patients with carcinoid syndrome in the clinic.
Etiology
The histologic origin of liver carcinoid tumor is not clear, and there are several possibilities: 1. ectopic pancreatic tissue; 2. scattered neural ectodermal cells and embryonic residues in the foregut, or primitive multipotential stem cells; 3. primitive neuroendocrine plate; 4. metaplastic endocrine cell epithelium.
Symptoms.
Pain in the right upper abdomen or hepatic region is most common, intermittent or persistent dull pain. Hepatic carcinoid tumor starts insidiously, and early tumors may not have any symptoms and signs. When carcinoid tumor grows to a certain degree, it may cause local symptoms (often caused by mechanical factors). Some patients have loss of appetite, dyspepsia, abdominal distension, nausea, vomiting, etc. A few patients are complicated with ulcers of stomach and duodenal bulb, so they may have symptoms of peptic ulcer, even vomiting blood and black stool.
The vast majority of liver carcinoid tumors do not have the clinical manifestations of abnormal increase of neuroendocrine products, and only individual cases show carcinoid syndrome, Drei-Ai syndrome, ectopic ACTH syndrome, and obstinate hypoglycemia, etc. In the advanced stage, patients often have anorexia, nausea and vomiting. In advanced cases, anorexia, emaciation, malaise, fever and other symptoms are common.
Liver enlargement is the most common sign, with hard texture, irregular surface and margins, often in the form of nodules, while a few cases with tumors deeply buried in liver parenchyma have smooth liver surface, with or without obvious pressure pain.
Examination
Blood test
In a few cases, the serotonin level is elevated to (0.5~3) mg/L (normal value is 0.1mg/L~0.3mg/L). Detection of tryptophan hydroxylase activity and expression in serum and tissues is helpful for diagnosis.
Urinalysis
Rarely, 5-hydroxyindoleacetic acid (5-HIAA) is excreted in the urine greater than 40mg per day (normal value is not more than 10mg per day) 5-HIAA test should not be taken in the 24 hours before the test, such as thiazides and amygdalic acid derivatives of drugs or foods that contain high amounts of tryptophan (e.g., pears, bananas, pineapple, tomatoes, eggplants, walnuts, etc.), so as to avoid a false-negative or false-positive result.
Diagnosis
Liver carcinoid tumors usually lack specific signs and symptoms and are histologically similar to hepatocellular carcinoma, making diagnosis difficult. The localization of liver carcinoid tumor often relies on B-mode ultrasonography, selective hepatic arteriography, computed tomography (CT) scan or liver radionuclide scan, or even magnetic resonance imaging (MRI).
Differential diagnosis
Carcinoid tumors of the gastrointestinal tract often develop liver metastasis at an early stage, and some of them also have the manifestation of carcinoid syndrome, therefore, when diagnosing liver carcinoid tumors, an extensive and meticulous examination should be carried out at first. Liver carcinoid tumors should also be differentiated from hepatocellular carcinoma, which has different clinical development from liver carcinoid tumors, does not have the manifestations of carcinoid syndrome, mostly occurs on the basis of cirrhosis, most of them have increased alpha-fetoprotein (AFP), and the tumor cells do not have carcinoid characteristics by immunohistochemistry and electron microscopy.
Complications
1. Some patients have loss of appetite, dyspepsia, abdominal distension, nausea and vomiting, etc. A few patients suffer from gastric and duodenal bulbar ulcers.
2. Advanced cases often have anorexia, emaciation, malaise and fever.
Treatment
1. Surgery
Surgical resection of liver carcinoid tumor is the most effective method. Early resection of primary lesions is the key to improve survival rate, and the effect of surgery is far better than that of primary liver cancer. Lobectomy in early cases can be expected to cure completely.
2. Hepatic artery embolization chemotherapy
Hepatic artery embolization chemotherapy is a kind of non-surgical tumor treatment method developed in 1980s, and in recent years, it has been applied to the treatment of hepatocellular carcinoma with more satisfactory results, and it is the first choice of non-surgical treatment, which mostly adopts iodized oil mixed with chemotherapeutic drugs to embolize blood supply of distal part of the tumor, and then embolize proximal hepatic artery with gelatin sponge to make it difficult to establish collateral circulation, which results in ischemia and necrosis of the tumor tissues. Chemotherapeutic drugs commonly used are cisplatin (CDDP), mitomycin (MMC), adriamycin (ADM), 5-fluorouracil (5-FU), and hepatic artery embolization chemotherapy should be carried out every 4-6 weeks, and it is better to repeat it for many times.
3.Systemic chemotherapy
Systemic chemotherapy can be chosen for patients who cannot undergo surgical resection or should not undergo hepatic artery embolization chemotherapy, but the efficacy is poor and the side effects of chemotherapy are large. Commonly used chemotherapeutic drugs are: 5-Fluorouracil (5-FU) or its derivatives (FT-207), mitomycin, adriamycin, cyclophosphamide, streptomycin.
4. Radiation therapy
Liver carcinoid tumors are not very sensitive to radiation therapy and the neighboring organs of liver are vulnerable to radiation damage, so the treatment effect is often unsatisfactory. Those who cannot be surgically resected can have certain curative effect by applying radiation therapy. If radiation therapy is combined with chemotherapy, traditional Chinese medicine or other supportive therapies at the same time, the result will be better.
5. Supportive therapy
When patients have nausea, vomiting or eat less, intravenous glucose can be given according to the condition. Add vitamin C, vitamin B6 and potassium chloride into the infusion, and give compound amino acid and albumin if necessary, and give blood transfusion if the anemia is significant.
Prognosis
The prognosis of liver carcinoid tumor is better than that of hepatocellular carcinoma, and most patients can survive for more than 4 years after active comprehensive treatment, including surgery and chemotherapy.