Primary malignant fibrous histiocytoma of the liver: imaging features of five surgically confirmed cases

Background: The purpose of the present study was to describe the various imaging features of primary malignant fibrous histiocytoma (MFH) of the liver, a rare tumor of mesenchymal origin. Methods: Sonography (n= 5), computed tomography (CT; n= 5), magnetic resonance (MR) imaging (n= 2), and hepatic arteriography (n= 3) in five patients who underwent partial hepatectomy for tumor resection were retrospectively reviewed and correlated with pathologic findings. Results: All tumors were clearly demarcated from surrounding hepatic parenchyma in sectional imaging with (n= 2) or without (n= 3) a fibrous capsule, which was pathologically verified. Internal architecture of abundant fibrosis, myxoid degeneration, and/or hemorrhagic necrosis reflected the sonographic, CT and MR imaging findings. Marginal tumor staining without definite tumor vasculature was the main feature of hepatic arteriography. There was no intratumoral calcification. All three tumors involving the right lobe of the liver invaded the right hemidiaphragm. Conclusion: Although there were no unique findings of primary hepatic MFH, a combined interpretation of various imaging modalities may elucidate the malignant nature of the tumor. Received: 20 May 1998/Accepted after revision: 1 July 1998     

Hepatic pseudolesion around the falciform ligament: prevalence on CT examination

Background: The purpose of this study was to determine the prevalence of hepatic pseudolesions seen around the falciform ligament on computed tomography (CT) of the abdomen obtained with intravenous administration of contrast material. Methods: We first retrospectively reviewed the CT scans of six patients in whom hepatic pseudolesions were seen around the falciform ligament. The abdominal CT scans of 587 patients were then prospectively analyzed for the presence of hepatic pseudolesions around the falciform ligament to determine the prevalence of this finding on CT examinations. Results: CT scans in the first six patients showed two types of hepatic pseudolesion around the falciform ligament. In three patients, hepatic pseudolesions were focal spared areas in fatty liver. In three patients, hepatic pseudolesions were developed in nonfatty liver. Prospectively, hepatic pseudolesions were found on five of 587 CT examinations (prevalence = 1%). A single hepatic pseudolesion was found in segment 4 on two examinations. Two hepatic pseudolesions (one in segment 4 and one in segment 3) were found together on three CT examinations. Conclusion: Hepatic pseudolesions around the falciform ligament are seldom seen on CT scan. However, recognition of these pseudolesions is crucial because they may be interpreted as true tumors. Received: 28 February 1995/Accepted: 29 March 1995     

Bile duct involvement in hepatocellular carcinoma: MR demonstration

Background: To determine the magnetic resonance (MR) features of hepatocellular carcinoma (HCC) with associated bile duct involvement. Methods: MR examinations of six patients (mean age, 62 years) demonstrating bile duct involvement due to HCC were retrospectively reviewed and compared to surgical and pathologic findings. Results: Three of the tumors were solitary, and three were multifocal. In two patients, MR showed direct biliary duct invasion by tumor. On T1-weighted MR images, four tumors were hypointense compared to the liver and two were isointense. On T2-weighted MR images, four tumors were hyperintense, and two were isointense. The two tumors studied with dynamic T1-weighted MR images obtained after intravenous administration of a gadolinium chelate, displayed enhancement similar to that of the liver. There was no evidence of a tumor capsule on either unenhanced or enhanced MR images. Intrahepatic bile duct dilatation was seen in five patients. The extrahepatic bile duct was normal in all cases. Conclusion: Although rare, HCC should be included when considering the etiology of intrahepatic bile duct obstruction. Imaging features suggestive of the diagnosis by MR include intrabiliary tumor or bile duct obstruction with an associated hepatic mass.     

Altered findings of hepatic arteriography after radiofrequency ablation of hepatocellular carcinoma: comparison of pre-ablation and post-ablation angiograms

Objective To evaluate the altered findings of hepatic arteriography after radiofrequency (RF) ablation of hepatocellular carcinoma which can potentially influence subsequent transcatheter arterial chemoembolization. Materials and methods Hepatic arteriograms of 26 index hepatocellular carcinomas in 24 patients treated only by RF ablation (M:F = 22:2, mean age 55 years), in which hepatic arteriography was performed before and after RF ablation, were retrospectively compared for the altered findings. Results The altered findings of hepatic arteriography after RF ablation of the hepatocellular carcinoma were arterio-portal shunt (n = 3), periablational enhancement (n = 5), varied caliber of the feeding artery to the index tumor (n = 12) among which eight decreased, and occlusion of an adjacent arterial branch (n = 8). Residual unablated or locally progressed tumor was not detected in post-RF ablation arteriography (n = 5) due to the arterio-portal shunt (n = 2) or the periablational enhancement (n = 3). The possibility of not detecting the residual unablated or locally progressed tumor was higher within 24 weeks after RF ablation (Mann–Whitney test, P = 0.041). Conclusion The findings of hepatic arteriography are altered after RF ablation, and the altered findings may increase the difficulty in performing super-selective transcatheter arterial chemoembolization due to undetected tumor staining, decreased caliber, or occlusion of the feeding artery.     

Small hepatic nodules in cirrhosis: ultrasonographic, CT, and MR imaging findings

Purpose: The purpose of this study was to assess the imaging findings of pathologically-proved small hepatic nodules 2 cm in size or smaller detected with ultrasonography in cirrhotic patients with suspected hepatocellular carcinoma (HCC). Materials and Methods: We evaluated sonographically detected 32 small hepatic nodules which were pathologically confirmed in 23 consecutive cirrhotic patients who were suspected of having HCC. Twenty-six lesions were confirmed with ultrasonographically-guided aspiration needle-core biopsy, and six with definitive surgery. Ultrasonographic examination records were retrospectively reviewed. CT, and MR images obtained with various imaging techniques were retrospectively reviewed by two radiologists in a blind fashion. Results: The 32 hepatic nodules were comprised of seven focal fatty changes, two large regenerative nodules, three low-grade dysplastic nodules, five high-grade dysplastic nodules, and fifteen HCCs. Ultrasonography showed various echogenicity for the hepatic nodules. The signal-intensity characteristics with T1-weighted spin-echo, in-phase gradient-recalled-echo, and dynamic MR imagings may be useful in distinguishing HCC from nonHCC nodules. Conclusions: Nearly half of small hepatic nodules detected with ultrasonography were nonHCC nodules. Ultrasonographic findings may not be reliable in characterizing small hepatic nodules in cirrhosis. CT and MR imaging obtained with the various techniques are still insensitive to these hepatic nodules. RID="ID="<e5>Correspondence to:</e5> M. Kanematsu Received: 25 August 1997/Revision accepted: 19 November 1997     

Fascioliasis: US, CT, and MRI findings with new observations

Background: The purpose of this study is to describe the ultrasonographic (US), computed tomographic (CT), and magnetic resonance imaging (MRI) findings in fascioliasis and to emphasize the impact of radiology in diagnosis. Methods: Radiologic findings in 23 consecutive patients with fascioliasis were prospectively recorded. All patients had at least one US and CT examination, and 10 of them were studied by MRI. All diagnoses were confirmed by serologic methods. In the first three cases, initial diagnosis was reached by microscopic demonstration of the parasites' eggs in bile obtained by US-guided gallbladder aspiration. Results: In the hepatic phase of fascioliasis, multiple, confluent, linear, tractlike, hypodense, nonenhancing hepatic lesions were detected by CT. On US, the parasites could be clearly identified in the gallbladder or common bile duct as floating and nonshadowing echogenic particles. MRI showed the lesions as hypo- or isointense on T1-weighted images and as hyperintense on T2-weighted images. Conclusions: CT findings in the hepatic phase and US findings in the biliary phase are characteristic of fascioliasis. Because clinical and laboratory findings of fascioliasis may easily be confused with several diseases, radiologists should be familiar with the specific radiologic findings of the disease to shorten the usual long-lasting diagnostic process. Received: 15 December 1999/Accepted: 26 January 2000     

MRI诊断56例肝移植术后移植肝实质并发症

目的 探讨MRI对肝移植术后移植肝实质并发症的诊断价值。方法 56例肝移植术后患者均接受MR常规序列扫描(Fiesta、Dual-Echo、FSPGR、FS FSE RT、DWI)及LAVA薄层动态增强检查,分析各序列影像表现。结果 肝实质动脉期异常灌注15例;肝内肿瘤复发9例,伴下腔静脉、门静脉及肝静脉癌栓3例;肝局灶性缺血、坏死2例,胆源性肝脓肿2例,肝脏周围炎2例,灶性肝出血2例,局灶性脂肪肝2例,弥漫性脂肪肝1例,肝淤血1例,肝嗜酸性肉芽肿1例,未分化肉瘤1例。结论 MRI可准确反映移植肝实质各种并发症,在其临床诊断及治疗方案的制定中具有重要价值。     

Cystic changes in hepatic and peritoneal metastases from gastrointestinal stromal tumors treated with Gleevec

Background: Tyrosine kinase inhibitor (Gleevec or STI-571) must be considered the treatment of choice for metastatic gastrointestinal stromal tumors (GISTs). The purpose of this article is to address and illustrate a long-term follow-up of computed tomographic (CT) radiologic findings in patients with metastases from GIST after Gleevec treatment. Methods: We performed a retrospective review of seven patients (four male, three female) with unresectable metastases from GIST who were treated with STI-571 in a 1-year period. Patients were followed every 2–4 months by contrast-enhanced CT for up to 12 months. The size and attenuation of hepatic and peritoneal metastases on CT were measured and correlated. Results: Hepatic metastases from GISTs showed significant decreased attenuation from a mean of 60 HU to a mean of 32 HU (p < 0.01) in the first 2 months and continued decreasing attenuation to 23 HU at the 12-month follow-up. These metastases superficially resembled simple cysts. Most metastases became smaller, with more defined borders, after treatment. Histologic examination in a resected specimen revealed hepatic cyst with no residual tumor cells, regression of omental lesions, and extensive necrosis. Conclusions: CT findings of unresectable hepatic and peritoneal metastases from GIST displayed decreasing, near cystic attenuation and size as an effective regression in response to STI-571 treatment.     

CT prediction of irresectability in esophageal carcinoma: value of additional patient positions and relation to patient outcome

Background: To improve computed tomographic (CT) prediction of local irresectability and to correlate preoperative CT findings with patient outcome. Methods: Eighty-five patients with esophageal carcinoma underwent CT in supine, left lateral decubitus, and prone positions. CT signs that were indicative of local irresectability included (1) an angle of contact >45° with the aorta; (2) obliteration of triangular fat pad between the tumor, aorta, and spine; (3) tumor contiguous with the aorta in all three positions; and (4) indentation of the airway in all three positions. Results: All CT signs indicative for local irresectability concerning the aorta had comparable percentages of false-positive scans (75%) when correlated with surgical findings. When correlated with pathologic findings, >45° angle of contact with the aorta yielded the fewest false-positive cases (9%). Concerning the airway, additional positions changed the staging correctly in 1 of 18 cases. Median survival was 21 and 8 months, respectively, for tumors considered CT resectable or irresectable. Conclusion: Additional patient positions do not improve the CT prediction of aortic invasion. Predicted resectability correlates with a significant longer life expectancy. Received: 29 January 1996/Accepted: 13 March 1996     

CT evaluation of the resectability of gastric cancer postchemotherapy

Background: To determine the accuracy of CT in the postchemotherapy assessment of resectability of gastric cancer. Methods: Thirty patients deemed to have unresectable gastric cancer on CT were studied. This was verified at laparotomy in 10 of these patients. Following initial assessment, all received three to eight cycles of chemotherapy aiming for disease control and potential resection. Serial CT examinations, endoscopy, and biopsy were performed after the fourth, sixth, and eighth cycle of treatment. The primary tumor and lymph nodes seen on CT were compared with operative findings. Results: After completion of chemotherapy, CT findings were correct in 23 patients. Fourteen of them had operable tumors and nine were inoperable. However, the CT findings were either equivocal or incorrect in the remaining seven patients. Conclusion: Chemotherapy is now able to downstage a previously inoperable gastric cancer, and CT is an accurate method in identifying those patients who can proceed to resection. Received: 24 October 1994/Accepted after revision: 6 April 1995     

Preoperative evaluation of Klatskin tumor: accuracy of spiral CT in determining vascular invasion as a sign of unresectability

Background: To assess the accuracy of spiral computed tomography (CT) in predicting the resectability of Klatskin tumor as determined by vascular invasion. Methods: Twenty-one consecutive patients with Klatskin tumor who had undergone laparotomy were included in this study. The preoperative thin-section (5-mm-thick) spiral CT scans of these patients were assessed for the surgical resectability of tumor by evaluating the vascular invasion. The criterion for vascular invasion indicating unresectability was the tumoral invasion of the proper hepatic artery or main portal vein or simultaneous invasion of one side of the hepatic artery and the other side of the portal vein. Results: All nine patients with tumors thought to be unresectable on the basis of CT findings had tumors that were unresectable at surgery (positive predictive value, 100%). Of 12 patients with tumors thought to be resectable, six had resectable tumors (negative predictive value, 50%). Spiral CT failed to detect small hepatic metastasis (n= 1), lymph node metastasis (n= 1), extensive tumor (n= 2) and variation of bile duct (n= 2), which precluded surgical resection. Conclusion: Spiral CT is a reliable method for detecting vascular invasion and unresectable tumors. However, it has limitations in detecting variations of the bile duct or the intraductal extent of tumor. Received: 24 November 1999/Accepted: 26 January 2000     

CT of agenesis and atrophy of the right hepatic lobe

Background: To identify and differentiate agenesis and severe atrophy of the right hepatic lobe on computed tomography (CT). Methods: The CT examinations of three cases of agenesis and 11 cases of severe atrophy of the right hepatic lobe were reviewed. We evaluated visibility of the three hepatic veins, the two main portal veins (including their branches if necessary), the dilated intrahepatic ducts, enlargement of the medial and lateral segments of the left lobe and caudate lobe of the liver, presence of a retrohepatic gallbladder, hyperattenuation of the atrophic liver parenchyma, posterolateral interposition of the hepatic flexure of the colon, and upward migration of the right kidney. Results: In the three cases of agenesis, no structure can be recognized as the right hepatic vein, right portal vein, or dilated right intrahepatic ducts. In the 11 cases of severe lobar atrophy, the right portal vein (or its branches) was recognized in eight cases, the right hepatic vein in four cases, and the dilated right intrahepatic ducts in 11 cases. The degree of enlargement of the lateral segment does not necessarily change inversely with the size of the medial segment and the caudate lobe. The retrohepatic gallbladder is present in eight cases (two in agenesis and six in atrophy). The phenomenon of hyperattenuation of the atrophic liver parenchyma was noted in six cases. Conclusion: Even though a retrohepatic gallbladder and a severely distorted hepatic morphology due to compensatory hypertrophy of the left and caudate lobes may raise a suspicion of agenesis of the right lobe of the liver, absence of visualization of all of the right hepatic vein, right portal vein and its branches, and dilated right intrahepatic ducts is a prerequisite of the diagnosis of agenesis of the right hepatic lobe on CT. In severe lobar atrophy, at least one of these structures is recognizable. Received: 1 March 1997/Accepted after revision: 25 June 1997     

Acute hepatic vein occlusion: spiral CT findings in an experimental study

Background: We investigatedspiral computed tomographic (CT) findings and underlying hemodynamic alterations in acute hepatic vein occlusion. Methods: In nine dogs, immediately after balloon occlusion of the right (n = 4) or left (n = 5) hepatic vein through the transjugular or transfemoral route, we performed single-level dynamic CT with intravenous administration of contrast medium. We created time attenuation curves of individual hepatic segments showing attenuation differences. To investigate underlying hemodynamic alterations, hepatic arteriograms were obtained in two dogs. Results: In all cases, there were three compartments with different time attenuation curves: normal, occluded, and adjacent. The normal compartment, which comprised segments far from the occluded hepatic compartment, showed the normal pattern of hepatic enhancement. The occluded compartment, which was the drainage territory of the occluded hepatic vein, showed high attenuation in the early arterial phase and low attenuation in the portal phase. The adjacent compartment, which shared the same portal vein with the occluded compartment and was drained by the patent hepatic vein adjacent to the occluded one, showed strong contrast enhancement in the late arterial and early portal phase. Spiral CT and hepatic arteriography demonstrated the arterioportal shunt and reversed portal venous flow in the occluded compartment, which drained into the adjacent compartment. Conclusion: Acute hepatic vein occlusion on spiral CT appears as mild, early arterial, high attenuation and portal low attenuation of the occluded compartment and strong enhancement in the late arterial and early portal phases of the adjacent compartment due to arterioportal shunt and reversed portal flow. Received: 15 March 2001/Revision accepted: 4 July 2001     

低度恶性肌纤维母细胞肉瘤的影像学表现

目的分析低度恶性肌纤维母细胞肉瘤(LGMS)的影像学表现,并与病理相对照。方法回顾性分析12例(13个病灶)经手术病理证实的LGMS的乳腺钼靶X线、CT、MRI表现特征及其病理诊断。结果 12例中,男4例,女8例,中位年龄44岁;11例单发,1例多发。12个病灶呈分叶和(或)膨胀性生长,边界清楚,瘤周水肿不明显,1个病灶呈浸润性生长。病灶大体T1WI呈均匀低信号,T2WI呈不均匀较高信号,内可见多条低信号分隔,偶有囊变、出血,增强后呈明显厚壁花环样强化。CT平扫病灶大体呈中等稍低密度,可见大片状钙化,实质部分CT值为30～47HU;增强后呈渐进性均匀或环形强化;乳腺钼靶X线片表现为分叶状中等稍高密度影。12例中,2例发生远处转移,3例复发,其中1例复发8次。影像学表现与病理结果相符。结论 LGMS的影像学表现具有一定特征性。     

Evaluation of pancreatic carcinoma with FDG PET

Background: To assess the diagnostic usefulness and clinical impact of positron emission tomography with [F-18]fluorodeoxyglucose (FDG PET) on the management of patients with known or suspected pancreatic carcinoma. Methods: Attenuation-corrected FDG PET was performed in 20 patients (12 male, eight female) with pancreatic carcinoma at the time of initial diagnosis (n = 7), for tumor surveillance after Whipple surgery (n = 11), and for reevaluation after chemoradiation therapy (n = 2). Visual analysis of PET images were correlated with the results of abdominal computed tomography (CT) and carbohydrate antigen (CA) 19-9 serum tumor marker level that were obtained within 1 month of the PET study. Diagnostic validation was by histology in nine patients and by clinical or radiologic follow-up (5–48 months) in 11 patients. Changes in therapeutic management that were prompted by PET were tabulated. Results: PET was concordant with the findings of abdominal CT in 14 patients (13 true positive, 1 true negative). PET detected clinically unsuspected lung lesions, confirmed subsequently by a chest CT, in one of these 14 patients. PET was discordant with CT in six patients. PET detected tumor recurrence in three patients in this group (15% of total) with nondiagnostic CT findings and elevated CA 19-9 serology. In two of these three patients, chemotherapy with gemcitabine was initiated based on PET localization of disease. Tumor was confirmed in the remaining one of the three patients at autopsy shortly after the PET study. FDG localization in a displaced loop of bowel resulted in an apparent false-positive hepatic lesion in one of six patients in the discordant group. PET underestimated the extent of metastatic disease in the remaining two of six patients due to hyperglycemia. Conclusion: In patients with suspected pancreatic carcinoma at the time of initial presentation, PET is complementary to abdominal CT and allows detection of unsuspected distant metastases. In patients with suspected recurrent pancreatic carcinoma, based on elevated or rising CA 19-9 serology, PET can localize the disease when abdominal CT is nondiagnostic as a result of posttherapy anatomic alteration. Imaging evaluation with PET may impact the clinical management of patients with pancreatic carcinoma. Received: 1 August 2000/Accepted: 20 September 2000     

单发婴儿型肝脏血管内皮细胞瘤的CT与MRI表现

目的 分析单发婴儿型肝脏血管内皮细胞瘤(IHE)的CT与MRI表现。方法 回顾性分析12例单发IHE,其中3例同时接受CT、MR平扫及增强扫描,5例仅接受CT平扫及增强扫描,4例仅接受MR平扫及增强检查。结果 12例单发IHE中,9例病灶在肝右叶,2例在肝左叶,1例累及肝脏右前叶及左内叶;CT平扫8例病灶均呈低密度,边界清晰,其中4例病灶内可见钙化;增强扫描5例病灶动脉期明显环形强化,3例边缘结节条索样强化;2例病灶由肝动脉供血,增强各期强化程度逐渐下降,以向心性强化为主。MR平扫7例中,6例病灶T1WI呈低信号,1例低信号内混杂高信号,T2WI均为高信号内斑片条索样低信号,T2抑脂明显高信号;增强后均以环形向心性强化为主。结论 单发IHE的特征性CT、MRI表现有助于提高诊断准确率。     

Iodized-oil retention within hepatic hemangioma: characteristics on iodized-oil CT

Objective: The purpose of this study was to describe the characteristic computed tomographic (CT) appearance of iodized-oil retention in hepatic hemangioma and to evaluate the duration of the retention of iodized oil on follow-up CT. Methods: Seventeen hepatic hemangiomas of 14 patients were studied with CT performed 1–3 weeks after injection of 2–9 ml of iodized oil (iodized-oil CT) for the characterization of focal hepatic lesions, which needed differential diagnosis with hepatocellular carcinoma in 10 patients, for therapy in two patients, and for chemoembolization therapy of accompanying hepatocellular carcinomas in two. Twelve patients had 1–7 follow-up CT scans within an interval of 1–38 months. Results: In all cases, iodized-oil CT showed iodized-oil retention within the tumor, regardless of tumor size, shape, location, and amount of injected iodized oil. The distribution was incomplete and predominantly peripheral in all cases. Central retention was also seen in seven cases, in which a relatively large amount of iodized oil was injected, but retention of iodized oil in the tumor was incomplete even in two cases in which a large amount of iodized oil was injected to relieve symptoms and in three cases in which prominent uptake of surrounding liver parenchyma was seen. Patterns of retention were predominantly spotty in five, predominantly nodular in four, and mixed in eight patients. Retention materials slowly washed out but persisted for at least 3 months and up to 38 months (mean = 18.1 months), and complete washout was not seen in any cases at follow-up CT. Conclusion: In all cases of hepatic hemangiomas, iodized oil was retained, and retention persisted over several months. Distribution and patterns of retention were characteristically peripheral, spotty, and nodular at iodized-oil CT. Knowledge of the iodized-oil CT appearance of hepatic hemangioma would be helpful to interpret follow-up CT studies of patients who have undergone iodized-oil chemoembolization procedures. Received: 22 August 1994/Accepted: 31 March 1995     

小儿肝脏未分化性胚胎性肉瘤9例的超声观察

目的总结小儿肝脏未分化性胚胎性肉瘤(Undifferentiated embryonal sarcoma of the liver,ES)的超声图像特点,为了提高超声对本病的正确诊断.方法回顾性分析9例UES的临床病理及影像特征并结合文献复习加以讨论.结果 9例均经病理证实.7例超声表现为低回声与高回声混合的实性为主兼有囊性的肿块.2例表现为囊性为主,囊间有少部分中等偏强回声的实性区域.9例肿瘤边界清楚,未见明显钙化,也未见转移.CT图像7例显示为囊性为主病灶,单房或多房,腔内少许软组织密度影,例显示为软组织密度的病灶.结论 UES超声表现为实性为主兼有部分囊腔,亦可囊性为主,但以前者多见,与CT图像恰恰相反.本组病例AFP阴性.     

Ultrasonographic study of calcified hepatic metastases: A report of 13 cases

Thirteen cases of calcified metastases were discovered by ultrasonography in cancer patients undergoing chemotherapy. Plain films revealed calcifications in only 9 of these 13 cases; CT scans confirmed the ultrasonographic findings in the remaining 4 cases. Although calcification of a metastasis corresponds to at least partial involution, it is always associated with a polymetastatic hepatic condition, and detection of a calcified metastasis therefore does not affect the prognosis.     

Intrahepatic bile duct dilatation secondary to hepatocellular carcinoma: CT features in 10 patients

Background: To determine the computed tomographic (CT) features of bile duct obstruction secondary to hepatocellular carcinoma (HCC). Methods: CT examinations of 10 patients (mean age, 58 years) with bile duct obstruction secondary to HCC were retrospectively reviewed. Results: All tumors were intrahepatic. Eight tumors were well-delineated and two were ill-defined. The largest diameters of tumor ranged from 1.5–6.0 cm (mean, 3.6 cm). All tumors were hypodense before contrast and did not contain calcification. After contrast, four tumors became hypodense, three were isodense, and three were hyperdense to the liver. No tumor demonstrated encapsulation. Diffuse intrahepatic bile duct dilatation was observed in seven patients. One patient had extrahepatic bile duct dilatation. Localized bile duct dilatation was observed in three patients, in the hemi-liver which contained the tumor. No tumor invaded the portal vein. Conclusion: Although rare, HCC should be included in the differential diagnosis of bile duct obstruction. This diagnosis should be suggested in patients with bile duct obstruction when CT shows an associated intra- or extrahepatic mass. Our results suggest that HCC responsible for bile duct obstruction is remarkable for the absence of encapsulation.