A 16-year-old girl in Macedonia presents to the local emergency department (ED) with a sudden onset of severe abdominal pain following what she describes as a "bear hug from a friend." The pain began a couple of hours before arrival to the ED. She describes the pain as sharp, constant, most intense in the right upper quadrant, and radiating to her right shoulder. The patient also reports having mild, dull abdominal discomfort and a feeling of progressive abdominal fullness for the past few months, but she has not sought medical attention for these symptoms. She also complains of having a diffuse, itchy rash that seems to have appeared around the same time as the onset of the abdominal discomfort. The patient has no history of food allergy and has not eaten any new foods before this episode. She denies having any fevers, nausea, or abnormal bowel movements. She has not had any changes in her skin coloration. She reports occasional use of acetaminophen in the last 2 weeks for the abdominal discomfort, but she is not otherwise taking any regular medications. She has no chronic medical conditions or past surgical history. She reports no significant family history. There are 2 dogs in her house which she cares for, but no other pets are present.
On physical examination, the patient is in obvious discomfort. Her body temperature is 99.1°F (37.3°C), she has a blood pressure of 110/70 mm Hg, and her pulse is 110 bpm. Her skin is pale and without jaundice, but she does have a diffuse urticarial rash that is most prominent on the trunk and proximal extremities. She appears well-nourished and well-developed. Her chest has symmetrical movements during respiration and clear breath sounds are noted on auscultation. Her heart sounds are normal, with a regular rhythm and no detectable murmurs. A firm mass overlying the liver edge in the right upper quadrant is noted on palpation. The entire upper abdomen is markedly tender and rigid, particularly in the right subcostal region.
The laboratory testing is remarkable for leukocytosis, with a white blood cell (WBC) count of 18.6 × 103/µL (18.6 × 109/L) and 40% neutrophils (0.40), 22% lymphocytes (0.22), 8% monocytes (0.08), and 21% eosinophils (0.21) (normal ranges: WBC, 4.5-11 × 103/µL; neutrophils, 40-70%; lymphocytes, 22-44%; monocytes, 4-11%; eosinophils, 0-8%). An elevated total bilirubin level of 1.98 mg/dL (33.8 μmol/L) was also noted (normal range, 0.3-1.0 mg/dL). Her aspartate aminotransferase (AST; also known as serum glutamic oxaloacetic transaminase [SGOT]) is 101 U/L and her alanine aminotransferase (ALT; also known as serum glutamic pyruvic transaminase [SGPT]) is 104.7 U/L. Her hematocrit and platelet counts are normal. An upright radiograph of the abdomen shows a nonspecific bowel gas pattern and no findings of pneumoperitoneum. An ultrasound is performed for a suspicion of possible gallbladder disease; it reveals a large hypoechogenic zone in the liver, with irregular margins and a small amount of free fluid around the liver. A computed tomography (CT) scan of the abdomen is subsequently performed (see Figures 1 and 2).
Hepatocelular Carsinoma
Discussion
Figure 2.
The CT scan of the abdomen reveals a fluid-filled cystic mass with an irregular margin in the fourth segment of the liver. The mass communicates with the gallbladder and is associated with a small amount of free fluid around the liver and in the peritoneal cavity. These imaging findings in the setting of eosinophilia, an associated allergic reaction, and a history of acutely worsening abdominal pain with sudden pressure applied to the abdomen, are consistent with a ruptured hydatid cyst.
Echinococcosis, otherwise known as hydatid or alveolar cyst disease, is an infection caused by the larval stage of small taeniid-type tapeworms of the Echinococcus species. Human disease is acquired by ingesting viable parasite eggs, usually in food. There are 3 forms of human hydatid disease. Echinococcus granulosus and Echinococcus vogeli produce unilocular cystic lesions, whereas Echinococcus multilocularis produces multilocular alveolar lesions that are locally invasive. E vogeli is uncommon and occasionally found in the South American highlands. E multilocularis is more common than E vogeli, but it is probably not the etiologic organism in this case. It is different from E granulosus in that it remains in a proliferative phase, is always multilocular, and survives in wild canines as the definitive hosts and small rodents as the intermediate hosts.
The adult form of E granulosus (3-5mm long) inhabits the intestines of definitive hosts (which are most commonly dogs, but it can also be found in coyotes or wolves). It has 3 proglottides, including immature, mature, and gravid. The gravid proglottid splits into eggs that can be found in the feces of the definitive host. Intermediate hosts, such as humans, sheep, cattle, and goats, get infected by consuming plants that are contaminated by the feces of affected animals or by direct contact with an affected animal. After humans ingest the eggs, they hatch into embryos in the small intestine. The embryos penetrate the intestinal mucosa, enter the portal circulation, and are carried to the liver.[3,4] Some are destroyed in the liver while others form into hydatid cysts. A small percentage of the eggs may pass through the liver and form cysts in other parts of the body, including the lungs, central nervous system (CNS), spleen, and pancreas. After the developing embryos localize in a specific organ, they transform and develop into larval echinococcal cysts.[1] This process is referred to as primary echinococcosis.
The cyst is composed of 2 layers: the endocyst, which is filled with clear fluid, and the pericyst, which is a fibrous capsule that develops as a host response to the growth of the echinococcal cyst.[3,4] Nutritive substances that contribute to the cyst's growth pass through the pericyst. The pericyst encompasses the endocyst, which is of larval origin.[2] It is composed of an outer laminated layer, or hyaline membrane, and an inner multipotential germinal layer. Daughter cysts develop from the inner aspect of the germinal layer, as do germinating cystic structures called brood capsules. New larvae, called protoscolices, develop in large numbers within the brood capsule. The cysts typically expand slowly over a period of years, at a rate of approximately 1-3 cm per year.[4]
In primary echinococcosis, approximately two-thirds of patients experience liver hydatid cysts. In 85% of cases, the cysts are located in the right lobe of the liver.[2] The second most commonly involved organ is the lungs. Because of the slow rate of growth of the cysts, patients with simple uncomplicated cysts are usually asymptomatic. The cysts are often discovered incidentally on routine imaging studies. In patients with liver echinococcosis, the most common symptoms are mild abdominal pain and an upper abdominal mass . On physical examination, hepatomegaly may be present in addition to a palpable abdominal mass. In about 10% of the patients, an elevated eosinophil count is noted.[1]
More dramatic findings are present when complications of hydatid cyst disease occur. The most frequent complication in hepatic echinococcosis is intrabiliary rupture, which occurs in approximately 10-15% of patients.[1] This results in biliary obstruction manifested by jaundice and biliary colic. In some cases, cholangitis or, even more rarely, pancreatitis may ensue. Infection of the cyst may also occur, and it is usually caused by bacteria residing in the biliary system. This may result in fever, leukocytosis, and possible formation of a liver abscess. Patients may be septic and should be treated aggressively with broad-spectrum antibiotics if signs of systemic infection are present.
Rupture of a hydatid cyst into the peritoneal cavity may happen spontaneously or may be caused by trauma, as in this case. Symptoms following the rupture are often dramatic and may include severe abdominal pain, syncope, or fever. Some patients exhibit signs of an allergic reaction, such as pruritus, urticaria, eosinophilia, or even anaphylaxis. Intraperitoneal rupture usually results in secondary implantation of cysts into the peritoneal cavity. Some rare but possible complications of liver echinococcosis include ascites, portal hypertension, Budd-Chiari syndrome, or compression of the vena cava. Rupture of the cyst into the vena cava is a very rare but universally fatal complication. Pulmonary hydatid cysts, when symptomatic, can cause chest pain, chronic cough, or hemoptysis. They may rupture into the bronchial tree and cause expectoration of a cyst fluid. Rupture of the hydatid cyst into the pleural cavity leads to pleuritic chest pain and dyspnea. Although rare, localization of hydatid cysts in the CNS can cause neurologic symptoms related to mass effect, including headache and seizures. Infection of skeletal tissue can cause pathological fractures as a result of invasion of the medullar cavity and slow bone erosion. Cardiac involvement may result in pericarditis or conduction abnormalities.[4]
Various radiographic and related imaging techniques can be used in detecting and evaluating echinococcal cysts in different parts of the body. Plain radiographs may show pulmonary cysts as round masses with uniform density.[1] Hydatid cysts will not typically be seen on plain abdominal radiographs unless calcification is present. Ultrasonography is the method of choice in detecting and evaluating hepatic hydatid cysts. It can reveal well-defined cysts with thick or thin walls in otherwise solid organs.[1] It can also elucidate the density of the fluid inside the cyst. The most pathognomonic finding on ultrasonography is the presence of daughter cysts; however, small cysts under 2 cm in size and peripherally located cysts can be missed by ultrasonography. Hydatid cysts may be unable to be distinguished from simple benign cysts if there are no signs of daughter cysts. CT scanning is no more sensitive or specific than ultrasonography, but it is useful in localization of the cyst and defining its relation to other structures, such as large blood vessels or biliary structures. This is of a great value when the clinician is considering surgery.[1]
Immunologic diagnosis is highly sophisticated and is used to distinguish simple benign cysts from hydatid cysts, as well as being used for postsurgical monitoring of persistent disease. The most valuable serologic test in the diagnosis of human hydatid disease is immunoelectrophoresis.[1] It is highly specific but requires high levels of antibodies for sensitivity. It is also the most valuable test for postsurgical monitoring because of its relative rapid reversion to negative when the organism is cleared. Enzyme-linked immunosorbent assay (ELISA) is a valuable test for primary diagnosis, but it is not useful in postsurgical follow-up because it takes years to revert to negative. Latex agglutination or indirect hemaglutination tests may be also be used for diagnosis. The sensitivity of these tests is best for hepatic disease, but it is much less sensitive for detecting lung or other organ disease.
Surgery is the traditional treatment of choice for hydatid cysts; however, a number of cysts are now treated with PAIR (percutaneous aspiration, infusion of scolicidal agents, and reaspiration). PAIR may be a reasonable approach for treating patients with inoperable disease, and it is typically performed while patients are on antihelminthic therapy to decrease the risk of cyst dissemination. Ultrasonographic staging is used to determine the ideal method of treatment. The success of the surgical approach depends on the location and size of the cyst and the potential for injury to surrounding structures. PAIR is contraindicated for superficially located cysts, cysts communicating with the biliary tree, and cysts with multiple internal septal divisions. Surgery is still preferred for complicated cysts under these conditions. Care must be made to remove cysts without contaminating the surrounding tissues, as anaphylaxis and dissemination of infectious protoscolices may result. In cases of intraperitoneal rupture, the peritoneal cavity should be searched for any hydatid elements and very thoroughly lavaged with large quantities of saline.
Albendazole and mebendazole are used for the medical treatment of echinococcosis in patients with contraindications for surgery. Albendazole is the preferred agent because of its greater absorption from the gastrointestinal tract, which results in higher serum levels. Multiple factors can be used to predict the patient response to treatment. These drugs may also be used for perioperative prophylaxis. The use of praziquantel as a prophylactic agent for preventing the implantation of spilled protoscolices is still controversial.
This patient was admitted to the surgery department and surgically treated the same night. The intraoperative findings included intraperitoneal and intrabiliary rupture of a hepatic hydatid cyst. Evacuation of the cyst fluid and its elements as well as sterilization with hypertonic saline solution was performed. Cholecystectomy was performed, and a T-tube was inserted. In the postoperative period, she was treated with albendazole and discharged to home after approximately 2 weeks. She was instructed to continue on the albendazole for a period of 3 months. At a 1 month postoperative follow-up visit, she was doing well and was without complications.
Acites
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