Biliary complications after liver transplantation: A computed tomography and magnetic resonance imaging pictorial review

Biliary complications are the most common complications after liver transplantation. Computed tomography (CT) and magnetic resonance imaging (MRI) are cornerstones for timely diagnosis of biliary complications after liver transplantation. The diagnosis of these complications by CT and MRI requires expertise, mainly with respect to identifying subtle early signs to avoid missed or incorrect diagnoses. For example, biliary strictures may be misdiagnosed on MRI due to size mismatch of the common ducts of the donor and recipient, postoperative edema, pneumobilia, or susceptibility artifacts caused by surgical clips. Proper and prompt diagnosis of biliary complications after transplantation allows the timely initiation of appropriate management. The aim of this pictorial review is to illustrate various CT and MRI findings related to biliary complications after liver transplantation, based on time of presentation after surgery and frequency of occurrence.     

Intracystic hemorrhage of a simple liver cyst mimicking a biliary cystadenocarcinoma

Simple liver cysts are rarely complicated by intracystic hemorrhage. We encountered a case of simple liver cyst that was morphologically similar to biliary cystadenocarcinoma, which was complicated by asymptomatic intracystic hemorrhage and successfully treated by right lobectomy. A large cystic lesion of the liver was detected in a 57-year-old woman during a mass screening health check. Abdominal ultrasonography (US) revealed that the cystic lesion, containing many hyperechoic papillary structures, occupied almost the entire region of the right hepatic lobe. In addition, a round mural nodule, measuring approximately 5 cm in diameter, was detected in the cystic wall. Abdominal computed tomography (CT) revealed that the inner part of the cystic lesion showed homogeneous low density, but CT did not show the round nodule detected by US. On T1-weighted sequence of magnetic resonance imaging (MRI), the lesion showed homogeneous high signals, together with a low-signal tumorous lesion in the cystic wall. T2-weighted sequence of MRI showed unhomogeneous high signals, together with high signals in the tumorous part. These findings did not exclude the possibility of a malignant cystic tumor, such as biliary cystadenocarcinoma. Therefore, right lobectomy was performed. Histological examinations of resected tissue specimens revealed that the lesion was a liver cyst containing a large amount of blood clot, and that the tumorous lesion detected by US and MRI was a large mass of blood clot which was partly liquefied. This case indicates the diagnostic importance of the morphological discordance between CT and US or MRI findings for liver cyst containing a large amount of blood clot. Received: May 7, 2001 / Accepted: December 27, 2001 Reprint requests to: Y. Kitajima     

Complications of hepatic hydatid cysts: ultrasound, computed tomography, and magnetic resonance diagnosis

A total of 179 hepatic hydatid cysts (HHCs) were studied by ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI). The diagnosis of HHC complications was established by US and CT, which permitted a distinction between intact cysts and those presenting with contained rupture, as demonstrated by a collapsed endocyst or a globally echogenic appearance. The diagnosis of HHC perforation into the main biliary tree was made by detection of a discontinuity in the cyst wall and/or the presence of hydatid material within the biliary system. Similarly, direct HHC rupture into different thoracoabdominal spaces was diagnosed by demonstrating cyst wall discontinuity and the presence of hydatid material within these spaces. Ruptured and infected cysts were difficult to distinguish from ruptured cysts with sterile content. The role of MRI is yet to be defined in the assessment of HHC complications.     

INTRABILIARY OBSTRUCTION DUE TO RUPTURED HEPATIC HYDATID CYST: EVALUATION WITH COMPUTED TOMOGRAPHY AND MAGNETIC RESONANCE IMAGING

Background: One of the most common and very serious complications of a hepatic echinococcal cyst is the intrabiliary rupture of the cyst and, in some cases, the obstruction of the biliary system. The effectiveness of computed tomography (CT) and magnetic resonance imaging (MRI) was evaluated for the preoperative diagnosis of hydatid cyst into the biliary tree. Methods: The techniques of CT, MRI and magnetic resonance (MR) cholangiography were used to examine nine cases of intrabiliary rupture of the hepatic hydatid cyst. The confirmation of the diagnosis was made at surgery in four cases and with endoscopic retrograde cholangiopancreatography in five cases. Results: By using CT and MRI, the intrabiliary rupture of an echinococcal cyst was diagnosed readily and accurately in all cases. In eight cases, we found a dilated intrahepatic biliary vessel near the ruptured echinococcal cyst, without any evidence of communication between the cyst and the biliary system. Also in six cases there was an abnormal configuration of the terminal part of the biliary radicle. Conclusion: This study suggests that a dilated biliary radicle with conical configuration of its end‐part and in close proximity with hydatid cyst is strong evidence of previous or active rupture of hydatid cyst into the biliary system. A combined study of CT or MRI and MR cholangiography is mandatory for proper preoperative evaluation of the intrabiliary rupture of hepatic hydatid cyst.     

Evaluation of hepatic cystic lesions

Hepatic cysts are increasingly found as a mere coincidence on abdominal imaging techniques, such as ultrasonography (USG), computed tomography (CT) and magnetic resonance imaging (MRI). These cysts often present a diagnostic challenge. Therefore, we performed a review of the recent literature and developed an evidence-based diagnostic algorithm to guide clinicians in characterising these lesions. Simple cysts are the most common cystic liver disease, and diagnosis is based on typical USG characteristics. Serodiagnostic tests and microbubble contrast-enhanced ultrasound (CEUS) are invaluable in differentiating complicated cysts, echinococcosis and cystadenoma/cystadenocarcinoma when USG, CT and MRI show ambiguous findings. Therefore, serodiagnostic tests and CEUS reduce the need for invasive procedures. Polycystic liver disease (PLD) is arbitrarily defined as the presence of > 20 liver cysts and can present as two distinct genetic disorders: autosomal dominant polycystic kidney disease (ADPKD) and autosomal dominant polycystic liver disease (PCLD). Although genetic testing for ADPKD and PCLD is possible, it is rarely performed because it does not affect the therapeutic management of PLD. USG screening of the liver and both kidneys combined with extensive family history taking are the cornerstone of diagnostic decision making in PLD. In conclusion, an amalgamation of these recent advances results in a diagnostic algorithm that facilitates evidence-based clinical decision making.     

Cystic tumors of the liver： A practical approach

Biliary cyst tumors （cystadenoma and cystadenocarcinoma） are an indication for liver resection. They account for only 5% of all solitary cystic lesions of the liver, but differential diagnosis with multiloculated or complicated biliary cysts, atypical hemangiomas, hamartomas and lymphangiomas may be difficult. The most frequent challenge is to differentiate biliary cyst tumors from hemorrhagic cysts. Computerized tomography （CT） and magnetic resonance imaging （MRI） are often not diagnostic and in these cases fine needle aspiration （FNA） is used to confirm the presence of atypical biliary cells. FNA, however, lacks adequate sensitivity and specificity and should always be used in conjunction with imaging. Pre-operative differentiation of cystadenoma from cystadenocarcinoma is impossible and surgery must be performed if a biliary cyst tumor is suspected. When multiple cystic lesions are observed throughout the liver parenchyma, it is important to exclude liver metastasis, of which colonic cancer is the most common primary site. Multiple biliary hamartomas （von Meyenburg complex） can appear as a mixture of solid and cystic lesions and can be confused with cystic metastasis. Strong and uniform T2 hyperintensity on MRI is usually diagnostic, but occasionally a percutaneous biopsy may be required.     

Role of endoscopic intervention in biliary complications of hepatic hydatid cyst disease

Objective. Biliary complications of hepatic hydatidosis are often difficult to detect and manage. The aim of this study was to present our experience on the effectiveness of endoscopic treatment modalities in cases of biliary complications of hepatic hydatid cysts. Material and methods. Over the past 10 years, 15 patients diagnosed with hepatic hydatidosis and manifesting symptoms and signs indicative of biliary involvement were examined by means of endoscopic retrograde cholangiopancreatography (ERCP) in our Gastroenterology Endoscopic Unit; 7 patients had already been operated on for hepatic hydatid cysts; one of them had a concomitant hydatid cyst in the lung. Diagnosis of the disease was based on a combination of ultrasonography (US), computed tomography (CT) and specific immunologic and/or microbiologic studies. Results. Biliary complications of hydatid cysts were detected by ERCP in 9 patients (60%). Eight (88.9%) patients displayed a communication between the hydatid cyst or its residual cavity and the biliary tree; 5 patients had daughter cysts or residual hydatid material within the biliary tree, 1 patient had a biliocutaneous fistula, 1 patient a postoperative biliary leakage and 1 patient had only an opacification of the hydatid cyst during ERCP. In one patient, ERCP showed stenoses of both of the main hepatic ducts due to their compression by the cyst. Jaundice (88.9%), fever (33.3%) and right upper quadrant abdominal pain (88.9%) were the most frequent manifestations. These complications were demonstrated by US and CT imaging in only 25% of the cases. Four patients underwent ERCP before surgery and 5 after surgery. Endoscopic management was successful in all patients, resulting in clearance of the biliary tree, closure of fistulas, stopping of biliary leakage and jaundice remission. No serious endoscopy-related complications were recorded, with the exception of a pulmonary hydatid cyst rupture during ERCP. Conclusions. This study suggests that endoscopic treatment modalities are helpful and safe methods in the treatment of biliary complications of hepatic hydatidosis before and after definitive surgical management of the hydatid cysts.     

Prenatal diagnosis of choledochal cyst using magnetic resonance imaging： A case report

Choledochal cysts are congenital anomalies of the biliary ducts, characterized by cystic dilatation of the ducts. Prenatal diagnosis of this anomaly using ultrasonography (US) has been well documented. Magnetic resonance imaging (MRI) has recently become an important complement to US in prenatal diagnosis of fetal anomalies. We herein report a patient in whom at 24 wk' gestation US suggested a right upper quadrant abdominal cyst and in whom at 26 wk' gestation MRI more clearly delineated the cyst and its surrounding structures and suggested a choledochal cyst, which was confirmed at postnatal surgery and histopathology.     

Giant biliary cystadenoma complicated with polycystic liver:A case report

Biliary cystadenoma(BCA)is a rare hepatic neoplasm.Although considered a benign cystic tumor of the liver,BCA has a high risk of recurrence with incomplete excision and a potential risk for malignant degeneration.Correct diagnosis and complete tumor excision with negative margins are the mainstay of treatment.Unfortunately,due to the lack of presenting symptoms,and normal laboratory results in most patients,BCA is hard to distinguish from other cystic lesions of the liver such as biliary cystadenocarcinoma,hepatic cyst,hydatid cyst,Caroli disease,undifferentiated sarcoma,intraductal papillary mucinous tumor,and hepatocellular carcinoma.Ultrasound(US),computed tomography(CT)and magnetic resonance imaging(MRI)may be necessary.They demonstrate intrahepatic cystic lesions with features such as mural nodules,varying wall thickness,papillary projections,and internal septations.Nevertheless,surgery is still the only means of accurate diagnosis.Definitive diagnosis requires histological examination following formal resection.We describe a57-year-old woman initially diagnosed with polycystic liver who was subsequently diagnosed with giant intra-hepatic BCA in the left hepatic lobe.This indicates that both US physicians and hepatobiliary specialists should attach importance to hepatic cysts,and CT or MRI should be performed for further examination when a diagnosis of BCA is suspected.     

Diagnosis of biliary strictures after liver transplantation： Which is the best tool？

AIM: To evaluate the diagnostic value of different indirect methods like biochemical parameters, ultrasound (US) analysis, CT-scan and MRI/MRCP in comparison with endoscopic retrograde cholangiography (ERC), for diagnosis of biliary complications after liver transplantation. METHODS: In 75 patients after liver transplantation, who received ERC due to suspected biliary complications, the result of the cholangiography was compared to the results of indirect imaging methods performed prior to ERC. The cholangiography showed no biliary stenosis (NoST) in 25 patients, AST in 27 and ITBL in 23 patients. RESULTS: Biliary congestion as a result of AST was detected with a sensitivity of 68.4% in US analysis (specificity 91%), of 71% in MRI (specificity 25%) and of 40% in CT (specificity 57.1%). In ITBL, biliary congestion was detected with a sensitivity of 58.8% in the US, 88.9% in MRI and of 83.3% in CT. However, as anastomotic or ischemic stenoses were the underlying cause of biliary congestion, the sensitivity of detection was very low. In MRI detected the dominant stenosis at a correct localization in 22% and CT in 10%, while US failed completely. The biochemical parameters, showed no significant difference in bilirubin (median 5.7; 4,1; 2.5 mg/dL), alkaline phosp-hatase (median 360; 339; 527 U/L) or gamma glutamyl transferase (median 277; 220; 239 U/L) levels between NoST, AST and ITBL. CONCLUSION: Our data confirm that indirect imaging methods to date cannot replace direct cholangiography for diagnosis of post transplant biliary stenoses. However MRI may have the potential to complement or precede imaging by cholangiography. Optimized MRCP-processing might further improve the diagnostic impact of this method.     

Imaging findings of biliary hamartomas

AIM: To evaluate the imaging findings of biliary hamartomas (von Meyenburg complexes, VMCs) and discuss the differential diagnosis with other related diseases.METHODS: Imaging findings of biliary hamartomas on ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), MR cholangiopancreatography (MRCP)and hepatobiliary scintigraphy were retrospectively analyzed in six patients.RESULTS: On ultrasound images, five of the six cases showed multiple small hyper- and hypo-echoic lesions with comet-tail echoes, especially when magnified by US with the usage of zoom function. In all the six cases,multiple tiny hypodense lesions less than 10 mm in diameter were revealed as scattered throughout the liver with no enhancement on CT. These tiny lesions were demonstrated to be hyper- and hypo-intensity on T2- and TI-weighed images, respectively, in three patients who underwent MRI examinations. MRCP was performed in two patients, and clearly showed multiple tiny irregular- and round-shaped hyper-intensity lesions.MRCP and hepatobiliary scintigraphy showed normal appearances of intra- and extra-hepatic bile ducts in two and one patients, respectively.CONCLUSION: Imaging modalities are useful in the diagnosis and differential diagnosis of VMCs. A correct diagnosis might be obtained when typical imaging findings are present even without a histological confirmation.     

Imaging findings of biliary hamartomas

AIM: To evaluate the imaging findings of biliary hamartomas (von Meyenburg complexes, VMCs) and discuss the differential diagnosis with other related diseases. METHODS: Imaging findings of biliary hamartomas on ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), MR cholangiopancreatography (MRCP)and hepatobiliary scintigraphy were retrospectively analyzed in six patients. RESULTS: On ultrasound images, five of the six cases showed multiple small hyper- and hypo-echoic lesions with comet-tail echoes, especially when magnified by US with the usage of zoom function. In all the six cases, multiple tiny hypodense lesions less than 10 mm in diameter were revealed as scattered throughout the liver with no enhancement on CT. These tiny lesions were demonstrated to be hyper- and hypo-intensity on T2- and T1-weighed images, respectively, in three patients who underwent MRI examinations. MRCP was performed in two patients, and clearly showed multiple tiny irregular- and round-shaped hyper-intensity lesions. MRCP and hepatobiliary scintigraphy showed normal appearances of intra- and extra-hepatic bile ducts in two and one patients, respectively. CONCLUSION: Imaging modalities are useful in the diagnosis and differential diagnosis of VMCs. A correct diagnosis might be obtained when typical imaging findings are present even without a histological confirmation.     

An extensive vertebral hydatidosis revealed by a lumbosciatica

The vertebral hydatidosis is uncommon. It causes problems in diagnosis and in management. A case of an extensive vertebral hydatidosis with few symptoms is reported. A 21-year-old man has consulted for recurrent lumbosciatica that has been evolving for 1 year. Clinical exam was normal. Plain radiographic films disclosed a lytic lesion throughout the bodies of L4 and L5 and calcifications thrown on the liver area. The computed tomography (CT) and the magnetic resonance (MR) images revealed multicystic bony lesions involving the lumbar spine with extension into the spinal canal. Abdominal ultrasound showed also cyst lesions in the right kidney and in the liver. The diagnosis of vertebral and abdominal (liver and kidney) hydatidosis was retained. Four sets of 4-week albendazole cures were given with a 2-week interval in between. Our case of extended vertebral hydatidosis with few symptoms confirms the clinical latency and diagnosis difficulties usually encountered in this disease. This often leads to a late diagnosis of the stage of spinal cord compression. Radiological diagnosis and determination of extension of the hydatid cyst are usually provided by CT and MRI. Vertebral hydatidosis should be evoked in lumbosciatica especially in endemic regions.     

Lymphoepithelial cyst of the pancreas

A case of lymphoepithelial cyst (LEC) of the pancreas is presented. A 48-year-old man complaining of general fatigue was found to have a heterogeneous water-dense mass protruding from the surface of the pancreas on plain computed tomography (CT). Dynamic CT disclosed septa within the mass. Magnetic resonance imaging (MRI) showed a hypoiintense mass on T1-weighted imaging, and a hyperintense mass on T2-weighted imaging. MRI with gadolinium enhancement revealed septa within the mass. Endoscopic ultrasonography showed septa and fine echogenic structures within the cystic echoic lesion. Endoscopic retrograde pancreatecraphy showed a normal duct system. Distal pancreatectomy with splenectomy was performed, with a suspected diagnosis of cystic neoplasms of the pancreas. Histopathologic examination disclosed LEC of the pancreas. Our case suggests that LEC should be considered in the differential diagnosis of cystic neoplasms of the pancreas.     

Alveolar Liver Echinococcosis: A Comparative Study of Three Imaging Techniques

Background: We compared the imaging findings in patients with alveolar liver echinococcosis using ultrasound (US), computerized tomography (CT) and magnetic resonance imaging (MRI) in a prospective study. Patients and Methods: 30 patients with alveolar echinococcosis (AE) were examined with the above imaging techniques. Results: 30 lesions were detected with all three methods and most lesions (n = 55) were detected with CT. Calcifications were seen in 15 lesions with US, in 21 with CT and in 16 with MRI. MRI best detected necrotic areas and multivesicular structures. Conclusion: US is the screening method of choice and should primarily be complemented by CT due to its ability to detect the greatest number of lesions and clear demarcation of the characteristic calcifications. MRI may facilitate the diagnosis in uncertain cases with noncalcified or partially calcified lesions by showing the characteristic multivesicular structure, necrotic areas and proximity to vascular structures. Received: July 5, 2000 · Revision accepted: January 10, 2001     

Diagnosis of cholangiocarcinoma

Cholangiocarcinoma is suspected based on signs of biliary obstruction, abnormal liver function tests, elevated tumor markers (carbohydrate antigen 19-9 and carcinoembryonic antigen), and ultrasonography showing a bile stricture or a mass, especially in intrahepatic cholangiocarcinoma. Magnetic resonance imaging (MRI) or computed tomography (CT) is performed for the diagnosis and staging of cholangiocarcinomas. However, differentiation of an intraductal cholangiocarcinoma from a hypovascular metastasis is limited at imaging. Therefore, reasonable exclusion of an extrahepatic primary tumor should be performed. Differentiating between benign and malignant bile duct stricture is also difficult, except when metastases are observed. The sensitivity of fluorodeoxyglucose positron emission tomography is limited in small, infiltrative, and mucinous cholangiocarcinomas. When the diagnosis of a biliary stenosis remains indeterminate at MRI or CT, endoscopic imaging (endoscopic or intraductal ultrasound, cholangioscopy, or optical coherence tomography) and tissue sampling should be carried out. Tissue sampling has a high specificity for diagnosing malignant biliary strictures, but sensitivity is low. The diagnosis of cholangiocarcinoma is particularly challenging in patients with primary sclerosing cholangitis. These patients should be followed with yearly tumor markers, CT, or MRI. In the case of dominant stricture, histological or cytological confirmation of cholangiocarcinoma should be obtained. More studies are needed to compare the accuracy of the various imaging methods, especially the new intraductal methods, and the imaging features of malignancy should be standardized.     

Diagnostik des Nierenzellkarzinoms

The frequent use of imaging modalities has led to a rising number of incidentally detected renal cell carcinomas (RCC). Especially the incidence of small asymptomatic renal masses has significantly increased. Due to considerable progress in disease management of RCC, for example new approaches in nephron-sparing surgery for localized tumors less than 4?cm, cross-sectional imaging is required for a more detailed preoperative characterization of renal masses. Most renal tumors (80%) are diagnosed incidentally by ultrasound examination (US). The detection rate can even be improved using duplex sonography or contrast-enhanced ultrasound (CEUS). If an accurate diagnosis is not possible with ultrasound, computed tomography (CT) examination may help to further qualify complicated cystic lesions of the kidneys. Computed tomography (CT) is still the reference standard for diagnosing primary tumor extent as well as for tumor staging. The most important criterion for assessing malignancy in a renal lesion is the evidence supplied by contrast-enhancement. Computed tomography also facilitates a differentiation of benign solid masses, such as angiomyolipomas and adenomas from malignant renal tumors and even the diagnosis of lymphomas is possible. Magnetic resonance imaging offers a better soft tissue contrast and is superior to a CT examination in diagnosing possible venous involvement and in the evaluation of inferior vena cava tumor thrombi. The differentiation of RCC subtypes, angiomyolipomas as well as distinguishing simple from complex renal cysts is also possible. The grading of different RCCs can be preoperatively estimated using dynamic contrast-enhanced MRI or measuring perfusion and diffusion within renal tumors. Due to a low sensitivity positron emission tomography/computed tomography (PET/CT) is not part of the routine diagnostic management for RCC. Nevertheless it plays an important role in the diagnosis of distant metastases and postoperative surveillance of advanced renal tumors. In some cases a complementary application of radiological imaging modalities, such as US, CT, MRI or PET/CT is required for an accurate differentiation of renal masses and for the diagnosis of RCCs.     

Current evidence for the diagnostic value of gadoxetic acid‐enhanced magnetic resonance imaging for liver metastasis

A variety of imaging techniques, including ultrasonography (US), multidetector computed tomography (MDCT), magnetic resonance imaging (MRI) and positron emission tomography combined with CT scan (PET/CT), are available for diagnosis and treatment planning in liver metastasis. Contrast‐enhanced MDCT is a relatively non‐invasive, widely available and standardized method for hepatic work‐up. Gadoxetic acid (gadolinium‐ethoxybenzyl‐diethylenetriamine pentaacetic acid; EOB Primovist®]) is a recently developed liver‐specific hepatobiliary MR contrast agent that offers both dynamic imaging as well as liver‐specific static hepatocyte imaging, referred to as the hepatobiliary phase. Following contrast injection, this technique reveals dynamic vascular phases (arterial, portal venous and delayed phases), in addition to the hepatobiliary phase upon uptake by functional hepatocytes. The overall sensitivity of gadoxetic acid‐enhanced MRI was significantly higher than that of contrast‐enhanced CT. Specifically, the higher sensitivity of gadoxetic acid‐enhanced MRI was observed in lesions smaller than 1 cm in diameter. Gadoxetic acid‐enhanced MRI is considered an extremely useful tool for the diagnosis of liver metastases. Future studies will focus on diagnostic algorithms involving combinations of modalities such as MRI, MDCT and/or ¹⁸F‐fluorodeoxyglucose PET/CT, which may impact the treatment plan for these patients.     

3 Crohn's disease: new imaging techniques

This chapter reviews the current state of imaging in Crohn's disease. Imaging plays an important role in the diagnosis and management of Crohn's disease. Imaging is complementary to the clinical assessment of the patient and other investigations including endoscopy. The choice of imaging modality depends on the clinical circumstances and local availability of resources and skills. Close co-operation between clinicians and radiologists is important. Barium radiology remains important. Magnetic resonance imaging (MRI) and ultrasound (US) should get special consideration because of the lack of ionizing radiation. MRI is particularly good at demonstrating the perianal complication of Crohn's disease. Computer tomography (CT) and US can be used for image-guided drainage of abscesses.     

New perspectives in the diagnosis of Echinococcus disease

Echinococcosis, an endemic disease on the Asian continent, is caused by the tapeworm Tenia Echinococcus, which produces cysts in the liver and other organs. I reviewed 157 patients with hydatid disease of the liver. The hydatid cysts were single in 125 patients and predominantly in the right lobe, but multiple in 31 patients, localized in both lobes or in the lung, spleen, pancreas, heart, or peritoneum. In 14 patients, early complications were manifested by rupture of the cyst into the biliary tract, the lung, or the peritoneum. Infection of the cysts was rare. Late postsurgical complications, noted in 10, were the development of an abscess or cirrhosis. I evaluated the importance of computed tomography (CT) in the diagnosis of hydatidosis of the liver and other visceral organs: It made a correct and accurate diagnosis in 96% of 157 patients. But, in ruptured or infected cysts, CT scans could not distinguish between a hydatid cyst and an abscess. Surgery is still the treatment of choice in hydatid disease. It is absolutely indicated in complicated cases, and is easy and curative in uncomplicated ones. I have used Mebendazole in 18 patients for 2 years without significant benefit, except in two patients with disseminated hydatidosis. Mebendazole stabilized the disease.