Federico Tanno, Hugo Tanno
The semiological concept of hepatic space-occupying mass (MOE) includes cysts, abscesses, and tumors, both benign and malignant, primary and secondary. It is for this reason that when studying a hepatic MOE different etiologies are considered, which encompass both infectious and tumor processes. The location of the liver as a filter organ of the portal circulation, explains the seat of infectious processes from the abdomen, produced by bacteria or parasites carried via the portal vein. Different primary tumors originate in the liver derived from the various cell lines that make up the organ as a whole, primary tumors are less frequent than secondary tumors that can be implanted in it, coming from different organs by different routes (hematic,
With essentially didactic criteria, cysts, abscesses and tumors will be treated separately.
Simple cyst : they are caused by congenital alterations in the development of the hepatic ducts. In their wall they present a thin layer of cells from the bile ducts, although they are not connected with the biliary tree. They have an incidence of 2.5% in the general population that increases with age. Simple cysts are easily differentiated from those produced by Polycystic Liver Disease (PHD) since the former are fewer in number (less than 4), there is no association with renal or pancreatic cysts and they do not have the dominant autonomic hereditary pattern characteristic of the EPH.
They are generally found by chance findings since they present without symptoms, except for those that, due to their expansion, produce compression or hepatomegaly, with little significant laboratory alterations. The finding of septa or papillae within the cyst should suggest cystadenocarcinoma. Symptomatic cysts are large, and the patient may feel abdominal distention and discomfort caused by its tension.
Hydatid cyst: In Argentina it is a frequent etiology, particularly in the south of the province of Buenos Aires, Entre Ríos and Patagonia. This regional incidence, linked to the distribution of the parasite (Echinococcus granulosus), makes it particularly important during the interrogation to specify the place of origin of the patient. The liver is affected in 50 to 75% of cases. The size of the cysts is variable, and can reach 20 cm. or more. The diagnosis is based on clinical suspicion and on imaging findings (ultrasound), since it is asymptomatic for a long time. It becomes evident when its size increases and produces compression phenomena (pain in the right upper quadrant, nausea, dyspepsia) or when it becomes complicated (fever). In this case it can become infected or open to the bile duct causing jaundice and cholangitis.
On palpation, the cyst is a smooth and painless tumor of increased consistency, with a typical reluctance when exerting pressure on it. This semiological impression is common to certain abscesses or abscessed tumors. However, the absence of pain, and the good general condition, allows a correct differential diagnosis. Eosinophilia is often seen on the hemogram, and erythrocyte sedimentation is normal.
Occupying mass enzymes are normal or slightly elevated, but not at the levels of other expansive conditions. The determination of arch 5, and the Elisa technique for hydatidosis make the diagnosis in more than 90% of cases, although there are cross-reactions with other parasites. Ultrasound is essentially helpful in showing a double wall that is characteristic for diagnosis.
Cistoadenoma: It is a benign tumor in which a thin epithelial layer surrounds the cyst, with liquid content, located in the liver parenchyma or rarely in the biliary tree. It represents less than 5% of cystic lesions of the liver. It can occur in childhood, although 80-85% of cases appear in middle-aged women. Symptoms are typical of compression of adjacent structures. 70% of patients present epigastric or right upper quadrant discomfort, sometimes with radiation to the shoulder. Half of the patients have a palpable abdominal mass and a third present with compression of the bile duct with jaundice and cholangitis. Some patients present symptoms of gastric compression due to nausea, vomiting, belching and anorexia. The most common complications are sepsis, rupture, and bleeding.
Pyogenic abscess : its frequency varies in different geographical areas due to the different prevalence of parasites, bacteria and helminths. The most frequent predisposing causes are diverticulitis, cholangitis, appendicitis and infections in organs of portal distribution. The incidence is increasing as a consequence of complications from the treatment of liver or pancreatic tumors (stent placement, sphincterotomy, embolization and radiofrequency).
The formation of the abscess itself is a defense mechanism of the body to try to contain the infection. If it reaches the liver by hematogenous route through the portal vein, abscesses are frequently multiple and in the right lobe. Less common is the entry into the liver via the arterial route, being small and homogeneously distributed in the two lobes. Another route is the biliary (cholangitis) being multiple in 40%.
The most common symptom is fever peaks (39-40º C), with chills. The pain is quite characteristic and becomes evident when palpating the intercostal spaces in hepatic projection. Some common symptoms are general weakness, anorexia, and nausea. Although jaundice predicts a complicated clinical course, it has no impact on mortality. In the laboratory, leukocytosis with a left shift, elevated erythrocyte sedimentation rate, and altered liver enzymes, with a predominance of ASAT as evidence of necrosis, is observed. There is also an increase in alkaline phosphatase and GGT. Bacteriological studies are necessary for the etiological diagnosis and its treatment. Both ultrasound, CT or MRI are useful to establish the diagnosis,
Amoebic abscess: Entamoeba histolytica is the main cause of liver abscess in the world, especially in tropical and sub-tropical areas, although it is rare in Argentina. It can be transmitted from person to person, being more frequent between 20 and 40 years, and can occur at any age. The greatest risk factor is having resided in endemic areas weeks or months before. Most patients report pain in the right upper quadrant, which is exacerbated by movement and radiates to the shoulder. Fever of 38-40 ° C with chills is common in most patients. On physical examination, the patient is pale and with deterioration of the general state, presenting painful hepatomegaly and pain on palpation of the intercostal spaces. If the abscess is in the left lobe, epigastric pain may appear. The laboratory is similar to a pyogenic abscess, sometimes showing a marked eosinophilia. Imaging cannot differentiate it from pyogenic abscess.
The benign tumors solids liver can be classified into: a) epithelial, such as hepatocellular adenoma and biliary cystadenoma; b) mesenchymal, such as hemangioma, lipoma and lymphangioma; c) tumor-like lesions such as focal nodular hyperplasia, hamartoma, and inflammatory pseudotumor. Among the malignant tumors solids are hepatocellular carcinoma, hepatocellular carcinoma and fibrolamellar cholangiocarcinoma. We will make a description of the most frequent ones.
The hemangioma is a congenital vascular malformation growing by ectasia, rather than hyperplasia or hypertrophy and compresses the hepatic parenchyma around it. Its incidence varies between 0.4 to 7.4%.
It is generally found incidentally, being more frequent in women and in the right lobe. Most are small and asymptomatic, less frequently they grow to a size that causes compression of other structures. Those greater than 5 cm. they are referred to as giants and can, at times, become symptomatic. Sudden pain may be due to infarction, necrosis, or rupture of the hemangioma; being any of these complications of exceptional presentation. The liver laboratory is absolutely normal. Diagnosis is simple with imaging techniques except on the rare occasions that it has atypical behavior. Magnetic resonance imaging shows in the T2 sequence a characteristic white image called "lamp on".
The focal nodular hyperplasia (HNF)it is a lesion of uncertain etiology. It is the second most frequent solid benign tumor, with an incidence that varies from 0.3 to 0.6%. It is generally unique and located in the right lobe, being more frequent in women. Their size is variable but most are less than 5 cm. Its diagnosis is suspected by ultrasound when a mildly hyperechoic mass with a central scar is detected. However, its confirmation must be made with other imaging methods such as CT or MRI. In most cases there are no symptoms and laboratory tests are normal. A small number of patients may present discomfort in the right upper quadrant, abdominal pain being seen in an exceptional way. Some patients may present with hepatomegaly with a palpable abdominal mass, but most have a normal physical examination.
Hepatocellular adenoma is a benign epithelial tumor that occurs more frequently in women, its incidence being close to 0.04%. It can be single or multiple and its size can reach 20 cm. Unlike hemangioma and UFH, the association with oral contraceptives is well documented.
Adenomas are diagnosed incidentally after ultrasound. Symptoms can be epigastric or HD pain or discomfort, accompanied by anorexia, nausea, and vomiting. If the pain is sharp and sudden, it may be due to the rupture or hemorrhage of the tumor, accompanied by hypotension and shock. The risk of this happening is higher in large adenomas, or in those patients who are taking oral contraceptives. Laboratory tests are normal, although FA and GGT may sometimes be increased. Malignant transformation of the adenoma is rare, but well documented. The differential diagnosis is with hepatocarcinoma, but the latter is seen in the context of chronic liver disease.
The hepatocellular carcinoma (HCC) is the leading cause of death in patients with cirrhosis and is the fifth frequency in relation to all tumors, although its incidence is increasing in recent decades.
80% of patients with HCC are cirrhotic, so any etiology that produces it will be a risk factor for its development.
The clinical picture is frequently masked by the symptoms of cirrhosis. Patients may present with ascites, jaundice, encephalopathy, or gastrointestinal bleeding from esophageal varices. Symptoms related to cancer, such as abdominal pain or impregnation syndrome (weight loss, anorexia, general decay), are frequent in advanced stages. Hemoperitoneum due to tumor rupture is rare. When settling in non-cirrhotic livers, the symptoms are those of a palpable tumor mass of increased consistency, in addition to presenting with fever, pain, weight loss, asthenia, and anorexia.
These signs pose the difficult differential diagnosis with a liver abscess. Metastases are common in bone, lung, and brain. The most common paraneoplastic manifestations are diarrhea, hypoglycemia, hypercalcemia, and thrombophlebitis.
Serum values of FAL, GGT, and 5 'nucleotidase are useful for diagnosis, but alpha-fetoprotein is undoubtedly the most accurate serum marker. Ultrasound allows the detection of HCC in asymptomatic stages, so the incorporation of cirrhotic patients to a surveillance program has markedly reduced tumors in advanced stages. The diagnosis of HCC with a size between 1 and 2 cm. With dynamic studies (ultrasound with contrast, CT and MRI with contrast) it is done with two images with arterial post-contrast enhancement, with rapid lavage in the venous phase. If the tumor is larger, a single image is enough. Biopsy is the gold standard for diagnosis, although in practice this resource is little used due to the danger of dissemination or bleeding, especially in patients with surgical or transplantation possibilities.
The hepatocarcinoma fibrolamellar corresponds to 2% of all malignant tumors of the liver. It usually affects adolescents and young adults and there is no gender predominance. There is no relationship described with oral contraceptives. Clinically, they manifest as pain on HD, weight loss, and hepatomegaly. Mild hypertransaminasemia and sometimes laboratory cholestasis may be seen on laboratory tests. Alpha-fetoprotein is normal, except for 10%, which can rise to 200 ug / L. These tumors are well circumscribed, firm in consistency, and lobulated at the edges. Occasionally there may be satellite nodules. The section has fibrous septa that radiate from a central scar, similar to focal nodular hyperplasia, with liver biopsy being the only diagnostic resource.
El cholangiocarcinoma originates in the bile ducts and is much less common than hepatocarcinoma. They are more frequent between the ages of 50 and 70. Its incidence does not increase in cirrhotic patients. Growth is usually slow and symptoms depend on the location. Jaundice is the most frequent symptom, the rest of the symptoms being similar to other tumors. In advanced cases, hepatomegaly or palpable gallbladder may appear. The laboratory corresponds to that of the occupant mass syndrome with increased FA, GGT and 5 'nucleotidase. Unlike HCC, alpha-fetoprotein is normal. The tumor marker that is most frequently present is CA 19-9 and CEA, but neither has sufficient sensitivity and specificity to be used as screening methods. Imaging studies confirm its presence, CholangioMRI and endoscopic retrograde cholangiopancreatography being first-line. This method allows biopsy and brushing of the lesion when it is proximal.
Secondary tumors : They are the most frequent malignant tumors of the liver. The double hepatic circulation and the fenestration of the sinusoids allow neoplastic cells to arrive from the splanchnic circulation, implanting themselves in the liver parenchyma. For this reason, tumors of the entire digestive system have the potential to metastasize to the liver.
The extension of a tumor to the liver usually causes symptoms, although on certain occasions it can be asymptomatic and associated with a surprisingly good general condition, as is the case with colonic metastases. On the surface of the liver they can be felt as painless nodules. Elevated FAL, GGT, and 5 'nucleotidase are characteristic in the laboratory. Serum tumor markers are an essential complement to determine the etiology. Assuming the diagnosis by the clinic and the laboratory, it must be confirmed with imaging methods (ultrasound, CT or MRI). To investigate the primitive tumor, the location of metastases must be taken into account.
The existence of liver metastases with undamaged lungs supports a tumor in a portal organ; On the other hand, the presence of pulmonary metastases without hepatic involvement suggests considering a tumor with a systemic location (breast, prostate, kidney, bones). Many times the primary tumor is not evident with conventional techniques, so a biopsy puncture is used for the definitive diagnosis.