Inflammatory pseudotumor of the liver in patients with recurrent pyogenic cholangitis: CT-histopathologic correlation

Hepatic pseudotumor: A diagnostic challenge

Hepatic pseudotumors are rare lesions of unknown origin, characterized by the proliferation of fibrous connective tissue and inflammatory cell infiltrates. They mimic malignant lesions clinically, and radiologically, given their non-specific clinical and imaging features. The pathophysiology of hepatic pseudotumor is incompletely understood and there are no standardized criteria for diagnosis. Pseudotumors have been reported to develop in various organs in the body with the lung and liver being the most common site. Hepatic pseudotumors develop in patients with underlying triggers of liver inflammation and injury, including infections, autoimmune liver diseases, bile duct injury, or surgery. Hepatic pseudotumors respond well to conservative treatment with antibiotics, and steroids and some may regress spontaneously, thus avoiding unnecessary resection. This condition is rewarding to treat. It is important to recognize pseudotumor as a distinct clinical entity and include it in the differential of liver masses with atypical imaging features.

Infant biliary cirrhosis secondary to a biliary inflammatory myofibroblastic tumor: A case report and review of literature

BACKGROUND

A biliary inflammatory myofibroblastic tumor (IMT) is a rare type of mesenchymoma that, although it has a broad age spectrum, usually occurs in adults. Diagnosis is difficult because biliary IMTs often exhibit nonspecific clinical symptoms and imaging features, resulting in delayed or inappropriate treatment. Although most IMTs are benign, some show malignant properties such as infiltration, recurrence, and metastasis.

CASE SUMMARY

Here, we retrospectively describe a 10-month-old infant who was admitted to our hospital due to stubborn jaundice. The patient responded poorly to routine medical treatment and his clinical manifestations and laboratory tests lacked specificity, so we turned to repeated ultrasound scans and other imaging examinations. As both hepatosplenic ultrasonography and diffusion-weighted magnetic resonance imaging demonstrated a space-occupying lesion, an exploratory laparotomy was performed. The final diagnosis made over two mo after the disease onset was infant biliary cirrhosis caused by a biliary IMT, which partially infiltrated into the liver. This infant is the youngest case of biliary IMTs that has been reported till now. The patient underwent an incomplete resection of the mass and Kasai Portoenterostomy. However, because of cirrhosis, he also received a paternal liver transplant. Since some IMTs show malignant properties, we proceeded with a three-year of follow-up; however, no recurrence or metastasis has been noted.

CONCLUSION

Neoplastic disease such as IMTs should be considered when routine medical treatment of obstructive jaundice is not successful. Observation of dynamic imaging changes is helpful for diagnosis. Periodic follow-up is necessary for IMTs.

Benign focal liver lesions masquerading as primary liver cancers on MRI

Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) are the most common primary liver malignancies. HCC and ICC have characteristic imaging findings, but a number of benign entities can appear similar and can cause diagnostic dilemma. Ideally, accurate and timely diagnosis of these conditions can help the patient to avoid a needle biopsy or even unnecessary treatment. In this article, we present various benign liver lesions that display imaging characteristics that are similar to HCC and ICC on magnetic resonance imaging (MRI) and discuss salient features that may assist in accurate diagnosis.

Clinicopathological features and post-resection outcomes of inflammatory pseudotumor of the liver

Backgrounds/Aims

Hepatic inflammatory pseudotumor (HIPT) is a rare disease characterized by chronic infiltration of inflammatory cells and area of fibrosis. The objective of this retrospective observational study was to investigate clinicopathological features and outcomes of patients who underwent hepatic resection (HR) for HIPT.

Methods

From 2009 to 2018, seven patients with HIPT underwent HR, accounting for 0.06% of 11,979 adults who underwent HR at our center.

Results

These seven patients included five men and two women. Their mean age was 62.3±11.6 years. In four patients with hepatitis B virus (HBV)-associated liver cirrhosis or chronic hepatitis, liver masses were suspected of hepatocellular carcinoma (HCC) or combined HCC-cholangiocarcinoma based on imaging studies. In three patients without HBV infection, two patients were suspected of HCC, for whom liver biopsy was not performed. One patient was suspected of liver abscess or HIPT, for whom percutaneous liver biopsy was performed and the mass was diagnosed with HIPT. However, this patient underwent HR owing to abdominal pain. No patient presented with abnormally elevated levels of alpha-fetoprotein, protein induced by vitamin K absence or antagonist-II, or CA19-9. During a mean follow-up period of 76.4±34.8 months, no patient experienced recurrence of HIPT.

Conclusions

HIPT, a rare form of liver disease, is often misdiagnosed as malignant liver tumor. Active histological diagnosis is warranted for patients with suspected HIPT to avoid unnecessary operation. HR can be indicated in case of diagnostic ambiguity of HIPT or under a clinical diagnosis of malignant liver tumor.

Rare presentation of inflammatory pseudotumour involving subcutaneous tissues with superficial fat sparing

We present a unique case of inflammatory pseudotumour involving gluteal subcutaneous tissue with the sparing of superficial fat and report its contrast-enhanced CT, F-18 fluorodeoxyglucose positron emission tomography/CT and pathological findings. Although rare, inflammatory pseudotumours have been reported with a diverse spectrum of locations; however, the involvement of the subcutaneous tissue overlying the gluteal muscles with sparing of the most superficial fat has not been reported.

An Enigmatic Liver Mass in a Child

Hepatic space occupying lesions in childhood are a diagnostic challenge, as they are caused by a variety of malignant and nonmalignant disorders with a different prognosis and, of course, treatment. They are often misdiagnosed or diagnosed only after surgical resection. A 14-year-old boy presented with abdominal pain, evening-rise fever with loss of appetite and weight. The patient also developed jaundice after 2 months of above symptoms. Ultrasound of the abdomen showed an irregular infiltrative mass in segment IV of the liver. Gadobenate disodium magnetic resonance imaging done showed T1 hypointense and T2 hyperintense lesions in segment VIII of the liver with extension into porta with delayed enhancement suggestive of fibrous tumor. Liver biopsy showed extensive liver parenchymal fibrosis with a mixed inflammatory infiltrate with eosinophils. Bacterial, tubercular, and fungal culture of liver biopsy were negative. Although serum IgG4 levels were 7.88 g/L (N =1.9 g/L), IgG4 staining of liver biopsy was negative. The patient was started on prednisolone 1 mg/kg considering the diagnosis of inflammatory pseudotumor (IPT). Twenty days after starting the steroid, mass lesions were converted into multicystic abscess requiring antibiotics and pigtail drainage. On follow-up, patient had improved symptoms with mass lesions turned into small-sized abscess cavity. Hepatic IPTs are difficult to differentiate from malignant tumors, as they are rare and can have variable imaging findings. To avoid inadvertent surgery, histological confirmation of the hepatic mass is essential. Steroids should be used with caution with close follow-up to prevent iatrogenic complications, such as a chronic liver abscess.

Tokyo Guidelines 2018: diagnostic criteria and severity grading of acute cholangitis (with videos)

Although the diagnostic and severity grading criteria on the 2013 Tokyo Guidelines (TG13) are used worldwide as the primary standard for management of acute cholangitis (AC), they need to be validated through implementation and assessment in actual clinical practice. Here, we conduct a systematic review of the literature to validate the TG13 diagnostic and severity grading criteria for AC and propose TG18 criteria. While there is little evidence evaluating the TG13 criteria, they were validated through a large-scale case series study in Japan and Taiwan. Analyzing big data from this study confirmed that the diagnostic rate of AC based on the TG13 diagnostic criteria was higher than that based on the TG07 criteria, and that 30-day mortality in patients with a higher severity based on the TG13 severity grading criteria was significantly higher. Furthermore, a comparison of patients treated with early or urgent biliary drainage versus patients not treated this way showed no difference in 30-day mortality among patients with Grade I or Grade III AC, but significantly lower 30-day mortality in patients with Grade II AC who were treated with early or urgent biliary drainage. This suggests that the TG13 severity grading criteria can be used to identify Grade II patients whose prognoses may be improved through biliary drainage. The TG13 severity grading criteria may therefore be useful as an indicator for biliary drainage as well as a predictive factor when assessing the patient's prognosis. The TG13 diagnostic and severity grading criteria for AC can provide results quickly, are minimally invasive for the patients, and are inexpensive. We recommend that the TG13 criteria be adopted in the TG18 guidelines and used as standard practice in the clinical setting. Free full articles and mobile app of TG18 are available at: http://www.jshbps.jp/modules/en/index.php?content_id=47. Related clinical questions and references are also included.

Cholangiocarcinoma and its mimickers in primary sclerosing cholangitis

Cholangiocarcinoma (CCA) is the most common malignancy in primary sclerosing cholangitis (PSC). Approximately half of CCA are diagnosed within two years of initial diagnosis and often have a poor prognosis because of advanced tumor stage at the time of diagnosis. Thus, rigorous initial imaging evaluation for detecting CCA is important. CCA in PSC usually manifests as intrahepatic mass-forming or perihilar periductal-infiltrating type. Imaging diagnosis is often challenging due to pre-existing biliary strictures and heterogeneous liver. Multimodality imaging approach and careful comparison with prior images are often helpful in detecting small CCA. Ultrasound is widely used as an initial test, but has a limited ability to detect small tumors in the heterogeneous liver with PSC. MRI combined with MRCP is excellent to demonstrate focal biliary abnormalities as well as subtle liver masses. Contrast-enhanced ultrasound is useful to demonstrate CCA by demonstrating rapid and marked washout. In addition, there are other disease entities that mimic CCA including hepatocellular carcinoma, confluent hepatic fibrosis, IgG4-related sclerosing cholangitis, inflammatory mass, and focal fat deposition. In this pictorial essay, imaging findings of CCA in PSC is described and discuss the challenges in imaging surveillance for CCA in the patients with PSC. Imaging findings of the mimickers of CCA in PSC and their differentiating features are also discussed.

A case of multiple inflammatory hepatic pseudotumor protruding from the liver surface after colonic cancer

INTRODUCTION

Inflammatory hepatic pseudotumor (IHPT) is an important benign liver disease because it is difficult to clinically and radiologically distinguish from malignant tumors.

PRESENTATION OF CASE

Here, we describe a case of a 67-year-old male patient diagnosed with multiple inflammatory hepatic pseudotumors. The patient had undergone left hemicolectomy for descending colonic cancer (T3 N0 M0 stage IIA) 2 years prior. He underwent segment 6 and segment 7 partial hepatectomy because of suspected liver metastasis. The patient had an unremarkable postoperative course and was discharged 7days after surgery. Marked infiltration of inflammatory cells was observed on histological examination. The patient was finally diagnosed with IHPT of the fibrohistiocytic type.

DISCUSSION

Repeated imaging studies over 1 month showed the spontaneous regression of the hepatic tumors. Therefore, knowledge regarding this condition is necessary to allow for treatment, even in the absence of experience. During examination, it may be important to ascertain lesion size. Moreover, percutaneous needle biopsy and follow-up examinations are necessary for cases of suspected IHPT.

CONCLUSION

Hepatectomy should be considered if the lesion is suspected to be an IHPT.

Immunoglobulin G4-related hepatic inflammatory pseudotumor invading the abdominal wall

A 50-year-old woman presented with epigastralgia. Computed tomography (CT) of the abdomen revealed a 6-cm well-enhanced mass extending from the left lobe of the liver to the abdominal wall, suggestive of cholangiocarcinoma. Liver and skin mass biopsies did not provide evidence of hepatic malignancy but were rich in plasma cells and sclerotic lesions. Subsequent detection of elevated serum immunoglobulin G4 (IgG4) led to a diagnosis IgG4-related inflammatory pseudotumor (IPT) of the liver. Treatment with systemic corticosteroids resulted in rapid clinical improvement. This case is the first report of an IgG4-related hepatic IPT invading the abdominal wall.

Necrotizing granulomatous inflammation of the liver

A 73-year-old patient with necrotizing granulomatous inflammation of the liver is presented. The computed tomography demonstrated 2 hypodense tumors with progressive enhancement in the liver. They became nearly isodense to the normal hepatic parenchyma on the delayed phase.

Imaging findings of mimickers of hepatocellular carcinoma

Radiological imaging plays a crucial role in the diagnosis of hepatocellular carcinoma (HCC) as the noninvasive diagnosis of HCC in high-risk patients by typical imaging findings alone is widely adopted in major practice guidelines for HCC. While imaging techniques have markedly improved in detecting small liver lesions, they often detect incidental benign liver lesions and non-hepatocellular malignancy that can be misdiagnosed as HCC. The most common mimicker of HCC in cirrhotic liver is nontumorous arterioportal shunts that are seen as focal hypervascular liver lesions on dynamic contrast-enhanced cross-sectional imaging. Rapidly enhancing hemangiomas can be easily misdiagnosed as HCC especially on MR imaging with liver-specific contrast agent. Focal inflammatory liver lesions mimic HCC by demonstrating arterial-phase hypervascularity and subsequent washout on dynamic contrast-enhanced imaging. It is important to recognize the suggestive imaging findings for intrahepatic cholangiocarcinoma (CC) as the management of CC is largely different from that of HCC. There are other benign mimickers of HCC such as angiomyolipomas and focal nodular hyperplasia-like nodules. Recognition of their typical imaging findings can reduce false-positive HCC diagnosis.

A case of hepatic inflammatory pseudotumor protruding from the liver surface

We report a case of a resected hepatic inflammatory pseudotumor (IPT) protruding from the liver surface. A 69-year-old male with diabetes mellitus was admitted to hospital for investigation of an hepatic mass. An irregularly shaped, low-echoic mass measuring 21 × 18 mm was identified by ultrasound in S6. On computed tomography, the tumor appeared to be growing extrahepatically. After contrast enhancement, the lesion showed persistent peripheral enhancement, while the central part was hypoenhanced. On T2-weighted magnetic resonance imaging (MRI), the central portion of the lesion was hyperintense compared with the periphery. EOB-enhanced MRI revealed the mass to be being hypointense in contrast to the surrounding liver parenchyma in the hepatobiliary phase. On diffusion-weighted images, the lesion was hyperintense. Percutaneous biopsy was not attempted to avoid tumor cell dissemination. The patient underwent partial hepatectomy because of suspected malignancy. Histopathological examination of the resected specimen revealed fibrotic tissue and abundant vessels in the periphery, while a massive infiltration of inflammatory cells and fewer vessels were observed in the center. The patient was finally diagnosed with hepatic IPT of the fibrohistiocytic type.

The analysis of enhancement pattern of hepatic inflammatory pseudotumor on contrast-enhanced ultrasound

OBJECTIVE

The aim of this study was to assess the role of contrast-enhanced ultrasound (CEUS) in the characterization of hepatic inflammatory pseudotumor (IPT).

METHODS

We retrospectively reviewed 36 cases of histopathologically diagnosed IPT. Nodule enhancement appearances during the arterial, portal, and delayed phases were defined as hyperenhancement, isoenhancement, hypoenhancement, and non-enhancement compared with the surrounding liver parenchyma. Statistical analysis was performed by the one-way ANOVA and χ (2) tests.

RESULTS

Among total 36 cases, 7 nodules were absent of contrast enhancement during all three phrases on CEUS. Twenty-nine nodules appeared different forms of enhancement in arterial phase. Diffuse homogeneous hyperenhancement, diffuse heterogeneous hyperenhancement, peripheral rim-like enhancement, and diffuse iso-enhancement were found in 10, 12, 5, and 2 of the nodules, respectively. Twenty-five nodules showed hypoenhancement in portal and delayed phases. Four nodules showed contrast washed out synchronously with normal liver parenchyma. The median time to enhancement, median time to peak, and median time to wash out of the nodules were 17 s (range 11-28 s), 23 s (range 14-42 s), and 45 s (range 23-100 s), respectively. No statistical significant differences were found in the above parameters of nodule enhancement and proportion of enhancement patterns when dividing the nodules into subgroups by nodule size.

CONCLUSION

IPT displays a variety of enhancement patterns due to pathological changes in the course of disease progression. Some characteristics on CEUS may be helpful in the differential diagnosis of IPT.

Retrospective and comparative study of inflammatory myofibroblastic tumor of the liver

BACKGROUND AND AIM

Inflammatory myofibroblastic tumor of the liver (IMTL) is a very rare benign disease with a good prognosis. The study aims to determine the clinical, radiological, and pathological characteristics of IMTL. The diagnosis and treatment strategies were discussed.

METHODS

A total of 11 patients with pathologically confirmed IMTL receiving treatment over a 15-year period were reviewed retrospectively. The analysis included demographics information and pertinent clinical data. Results obtained from patients with hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (IHCC), and metastatic liver cancer (MLC) receiving surgical resection were compared.

RESULTS

In comparison to HCC, IHCC, and MLC, IMTL has an earlier onset (P < 0.001). IMTL patients had significantly lower aspartate aminotransferase (P = 0.003) and higher alkaline phosphatase (P = 0.034) than HCC patients, and higher gamma-glutamyl transpeptidase (P = 0.010) than MLC patients. Increased serum α-fetoprotein level was detected in only one patient. Serum α-fetoprotein was significantly lower in patients with IMTL (P = 0.000) than in those with HCC but not IHCC (P = 0.558) or MLC (P = 0.514). In contrast to elevated serum CA19-9 in patients with HCC/IHCC/MLC, the serum CA19-9 in IMTL cases was generally normal (vs HCC P = 0.008; vs IHCC P = 0.000; vs MLC P = 0.022). In nine IMTL patients, the tumor appeared as a hypoechogenic solid mass on the ultrasonography. In contrast, most patients with HCC, IHCC, or MLC showed hybrid echo. In contrast computed tomography and magnetic resonance imaging, the lesion of IMTL and MLC appeared as peripheral enhancement.

CONCLUSION

Lab tests, imaging features, and patient history are helpful in the differential diagnosis of IMTL from HCC/IHCC/MLC. Surgical resection is curative for IMTL.

Hepatic inflammatory pseudotumor with elevated serum CA19-9 level mimicking liver metastasis from rectal cancer: report of a case

Inflammatory pseudotumor (IPT) of the liver is rare, and differential diagnosis from malignant tumors is difficult. We herein report a case of IPT of the liver with marked elevation of carbohydrate antigen 19-9 (CA19-9). A 72-year-old woman, who underwent low anterior resection for rectal cancer, had low-grade fever and epigastric pain. The patient has well-controlled idiopathic thrombocytopenic purpura (ITP) with steroid maintenance treatment. Abnormal laboratory findings included serum carcinoembryonic antigen of 15.9 ng/mL and CA19-9 up to 14,632 U/mL. Computed tomography revealed a low-density lesion, and magnetic resonance imaging demonstrated a high intensity lesion on T1, T2-weighted, and diffusion-weighted images (55 × 22 mm in the Couinaud's segment 4 of the liver). However, 1 month after the appearance of the symptom, serum level of CA19-9 suddenly decreased to 37 U/mL. The tumor decreased spontaneously to 20 × 10 mm. Seven months later, the tumor had reduced to 18 × 11 mm. With a diagnosis of IPT, the patient remains well without regrowth of the tumor at 1 year follow-up after CA19-9 decrease to normal limits.

Spectrum of multilocular cystic hepatic lesions: CT and MR imaging findings with pathologic correlation

A multilocular cystic hepatic lesion detected at computed tomography (CT) and magnetic resonance (MR) imaging is a common but nonspecific radiologic finding that can cause potential challenges for differential diagnosis. This imaging pattern may be observed in a wide spectrum of common and uncommon neoplastic or nonneoplastic entities. Neoplastic lesions include cystadenoma, cystadenocarcinoma, hepatocellular carcinoma (HCC), metastases, mesenchymal hamartoma, and inflammatory myofibroblastic tumor. Nonneoplastic lesions include hepatic abscess, echinococcal cyst, intrahepatic hematoma, and biloma. The multiple coalescent cysts seen in polycystic liver disease may exhibit an imaging pattern similar to that of a multilocular cystic lesion. Mural nodularity, irregular thickness of the septa, ragged inner surface, and typical enhancement pattern in the solid portion of the lesion are often indicative of malignancy, although multilocular primary or secondary malignant tumors are uncommon. Recognition of the more common necrosis or cystic change of HCC and metastases induced by locoregional or systemic treatment also is important. The nonenhanced cystic component may be composed of different types of fluids (eg, serous, mucinous, proteinaceous, hemorrhagic, bilious, or mixed) or spontaneous or treatment-related necrosis, whereas the septa may be formed by a wide range of tissues depending on the lesion type. An understanding of the CT and MR imaging findings of these lesions and their respective pathologic correlation aids in accurate diagnosis.

Inflammatory pseudotumor of the liver: a rare case of recurrence following surgical resection

Inflammatory pseudotumor (IPT) of the liver is a rare, benign lesion that may be mistaken for malignancy. IPTs are difficult to diagnose due to non-specific clinical, laboratory and imaging features. We report the case of a 38-year old Asian male who presented with fatigue, weight loss and hepatomegaly. He was found to have a large hepatic IPT and underwent surgical resection; approximately two and a half years later, he developed acute cholangitis secondary to IPT recurrence. We present the imaging features of hepatic IPT using ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI). We also review the literature on the diagnosis and management of this disease. The unique features of this case include the IPT's recurrence following surgical resection, large size and multiple modalities presented.

Clinical features, image findings, and prognosis of inflammatory pseudotumor of the liver: a multicenter experience of 45 cases

Background/Aims

Inflammatory pseudotumor (IPT) of the liver is a rare disease characterized by chronic infiltration of inflammatory cells. However, the clinical characteristics and outcomes of IPT remain uncertain.

Methods

Clinical features, image findings, and outcomes of 55 patients with histologically proven IPT were evaluated.

Results

They consisted of 26 men and 19 women with median age of 65 years. Serum carcinoembryonal antigen and carbohydrate antigen 19-9 levels were normal in 42 patients (93.3%). Enhanced CT scans indicated poorly defined peripheral enhancement (82.5%) at the arterial phase and poorly defined hyperattenuating lesions with internal hypoattenuating areas at the equilibrium phase (77.0%). Gadolinium-enhancement MRI revealed poorly defined peripheral rim-like enhancement (77.8%). Ten patients underwent surgical resection and 35 were treated conservatively with or without antibiotics. No recurrence was noted after surgical resection during follow-up (1 to 48 months). In all patients who received conservative treatment, complete resolution or size reduction was noted during follow-up (1 to 192 months).

Conclusions

CT and MRI provide clues to the diagnosis of IPT in patients with liver masses and normal tumor markers. However, due to the lack of pathognomonic findings, the clinician's suspicion and histological diagnosis are necessary to make an accurate diagnosis of IPT.

Mid common bile duct inflammatory pseudotumor mimicking cholangiocarcinoma. A case report and literature review

INTRODUCTION

Biliary inflammatory pseudotumors (IPTs) represent an exceptional benign cause of obstructive jaundice. These lesions are often mistaken for cholangiocarcinomas and are treated with major resections, because their final diagnosis can be achieved only after formal pathological examination of the resected specimen. Consequently, biliary IPTs are usually managed with unnecessary major resections.

PRESENTATION OF CASE

A 71-year-old female patient underwent an extra-hepatic bile duct resection en-bloc with the gallbladder and regional lymph nodes for an obstructing intraluminal growing tumor of the mid common bile duct (CBD). Limited resection was decided intraoperatively because of negative for malignancy fast frozen sections analysis in addition to the benign macroscopic features of the lesion. Histologically the tumor proved an IPT, arising from the bile duct epithelium, composed of inflammatory cells and reactive mesenchymal tissues.

DISCUSSION

The present case underlines the value of intraoperative reassessment of patients undergoing surgical resection for histopathologically undiagnosed biliary occupying lesions, in order to optimize their surgical management.

CONCLUSION

The probability of benign lesions mimicking cholangiocarcinoma should always be considered to avoid unnecessary major surgical resections, especially in fragile and/or elderly patients.

Multiple hepatic inflammatory pseudotumours diagnosed after laparoscopic excisional biopsy

Inflammatory pseudotumours (IPTs) may occur in almost every organ of the human body, the liver being the second most frequent organ which is affected. Inflammatory pseudotumours of the liver are rare benign lesions of unknown aetiology, which usually present as solitary liver masses of variable sizes. The differential diagnoses of malignant liver tumours are challenging and they usually require biopsies and histologic examinations. We are presenting the case of a patient with multiple hepatic lesions which mimicked liver metastases. Two percutaneous biopsies were inconclusive. The definitive diagnosis of multiple hepatic inflammatory pseudotumours was made after a laparoscopic exploration with an excisional biopsy of liver lesions and their pathologic evaluation. All lesions disappeared after several months, without any further treatments.

Inflammatory pseudotumor in the mediastinum: imaging with (18)F-fluorodeoxyglucose PET/CT

Mediastinal inflammatory pseudotumor is a rare benign disease with its capability for local invasion and rapid growth. We present a case of middle-mediastinal inflammatory pseudotumor and report its contrast-enhanced chest computed tomography, (18)F-fluorodeoxyglucose positron emission tomography/computed tomography and pathologic findings.

Recurring multicystic inflammatory pseudotumor of the liver: a case report

Inflammatory pseudotumor (IPT) of the liver is a rare benign lesion for which imaging diagnosis remains a challenge. We report the case of a 39-year-old Algerian woman, who presented epigastric pains combined with fever and jaundice. Ultrasound, CT scan and MRI showed the presence of a 10 cm-long multi-septated cystic mass of the left lobe, with peripheral enhancement. A left-hepatectomy was performed and histopathology revealed an IPT of the liver. During the 4 following years, the patient had three other recurrences of liver IPT at various locations distinct from the original, revealed by the same clinical symptoms. During these relapses, the lesions did regress thanks to a medical treatment. This observation underlines the difficulty of the diagnosis and treatment of liver IPT.

Inflammatory pseudotumors mimicking intrahepatic cholangiocarcinoma of the liver; IgG4-positivity and its clinical significance

BACKGROUND

Inflammatory pseudotumor (IPT) of the liver is a benign condition with a good prognosis. However, it is difficult to distinguish clinical and radiological findings of IPT from those of malignancies. The aims of this study are to determine the clinical, radiological, and pathological characteristics, particularly relating to the role of the autoimmune mechanism in the development of inflammatory pseudotumours (IPTs) of the liver, and to suggest appropriate diagnostic and therapeutic strategy.

STUDY DESIGN

The clinical, diagnostic, and pathological characteristics including IgG4 immunohistochemical stain and follow-up data of 22 IPT patients were retrospectively analyzed.

RESULTS

The patients were 16 men and 6 women with a mean age of 59 years. Fifteen patients (68.2%) had associated biliary diseases. Of the 16 patients treated conservatively, the masses completely resolved in 10 patients, and reduced in size in 5 patients within the first 6 months. The remaining 6 patients were treated by surgical resection. IgG4 staining of 17 tissue samples from 22 patients were negative, most of the infiltrate being of fibrohistiocytic type, whereas 4 of 5 lymphoplasmacytic cells of dominant tumors show positive staining of IgG4. Although IgG4-related sclerosing cholangitis was mostly of lymphoplasmacytic type, other histological and clinical characteristics were similar in both types of IPTs.

CONCLUSIONS

IPTs of the liver can be diagnosed based on radiological and pathological findings by needle biopsy. Although the lymphoplasmacytic type of IPTs seems to correspond to IgG4-related disease, as assessed by IgG4 immunohistochemical stain, its clinical significance is unknown. Although most IPTs can be resolved with conservative therapy, surgical resection should be considered in cases of uncertain biopsy result, presumed malignant lesion, combination with other pathology, or lack of response to conservative management.

Different imaging findings of inflammatory myofibroblastic tumor of the liver

Inflammatory myofibroblastic tumor (IMT) in the liver is an uncommon lesion of uncertain pathogenesis. In most cases, symptomatological imaging and clinical studies suggest malignancy. We report a case of liver IMT with imaging findings from positron emission tomography/computed tomography (PET/CT), contrast-enhanced computed tomography (CECT) and contrast-enhanced ultrasonography (CEUS). This report was the first to depict a PET/CT scan of a liver IMT that revealed an inhomogeneous, intense (fluorine 18)-fluoro-2-deoxy-D-glucose uptake. The CECT and CEUS images showed a hepatic artery supplying blood to the mass and necrosis. The characteristic histopathological features and the presence of spindle cells expressing smooth muscle actin, collagen fibers and lymphocytes allowed for the diagnosis of liver IMT. Recognizing such findings will help to achieve a correct diagnosis and may prevent inappropriate treatment.

Inflammatory pseudo-tumor of the liver: a rare pathological entity

Inflammatory pseudo-tumor (IPT) of the liver is a rare benign neoplasm and is often mistaken as a malignant entity. Few cases have been reported in the literature and the precise etiology of inflammatory pseudotumor remains unknown. Patients usually present with fever, abdominal pain and jaundice. The proliferation of spindled myofibroblast cells mixed with variable amounts of reactive inflammatory cells is characteristics of IPT. We reviewed the literature regarding possible etiology for IPT with a possible suggested etiology.

Inflammatory pseudotumor in the liver associated with intrahepatic bile duct stones mimicking malignancy

We describe a 71-year-old man with an inflammatory tumor arising in segment 5 of the liver. The patient was admitted because of acute pain in the right upper quadrant of the abdomen and fever. Initial laboratory tests revealed the following: serum alkaline phosphatase concentration, 634 IU/L; serum gamma glutamic transpeptidase concentration, 1,378 IU/L; serum C-reactive protein concentration, 0.89 mg/dL; and total bilirubin concentration, 8.9 mg/dL. Abdominal ultrasonography, computed tomography (CT), and magnetic resonance imaging showed a mass, 3 cm in diameter, in segment 5 of the liver. Magnetic resonance cholangiopancreatography showed a lesion of moderate-to-high signal intensity on T2-weighted images of segment 5. Endoscopic retrograde cholangiopancreatography revealed a common bile duct stone. The intrahepatic bile ducts of segment 5 could not be visualized after the use of contrast material. Endoscopic sphincterotomy was performed to remove the common bile duct stone. Antibiotics were administered soon after stone removal, and fever gradually resolved. Positron emission tomography revealed hot spots in segment 5 of the liver. Three weeks after discharge, the patient was readmitted with an acute pain in the right upper quadrant of the abdomen. Abdominal ultrasonography, CT, and magnetic resonance imaging showed enlargement of this area. Inflammatory changes of segment 5 due to cholangitis with intrahepatic bile duct stones was diagnosed. Because malignant disease could not be completely ruled out, segment 5 of the liver was resected. Macroscopic examination of the resected specimen revealed a gray, fibrotic, solid tumor associated with intrahepatic bile duct stones. Microscopic examination of the tumor showed proliferation of spindle-shaped myofibroblastic cells in a mixed myxoedematous, dense fibrotic stroma, associated with infiltration by various acute and chronic inflammatory cells. The postoperative course was uneventful, and the patient was discharged on postoperative day 16.

Benign hepatic tumors and iatrogenic pseudotumors

Myriad benign tumors may be found in the liver; they can be classified according to their cell of origin into tumors of hepatocellular, cholangiocellular, or mesenchymal origin. Common benign hepatic tumors may pose a diagnostic dilemma when they manifest with atypical imaging features. Less frequently encountered benign hepatic tumors such as inflammatory pseudotumor or biliary cystadenoma demonstrate less specific imaging features; however, awareness of their findings is useful in narrowing differential diagnostic considerations. In addition, certain iatrogenically induced abnormalities of the liver may be confused with more ominous findings such as infection or neoplasia. However, knowledge of their common imaging appearances, in addition to the clinical history, is critical in correctly diagnosing and characterizing iatrogenic abnormalities of the liver. Familiarity with both expected and unexpected imaging appearances of common benign hepatic tumors, less commonly encountered benign hepatic tumors, and iatrogenic abnormalities potentially masquerading as hepatic tumors allows the radiologist to achieve an informed differential diagnosis.

Recurrent pyogenic cholangitis: from imaging to intervention

OBJECTIVE

The objective of this article is to familiarize the reader with the sonographic, CT, MR cholangiopancreatography, and ERCP appearances of recurrent pyogenic cholangitis and to briefly review the role of interventional radiology in the management of this disease.

CONCLUSION

Recurrent pyogenic cholangitis is a complex disease, the incidence of which is increasing in Western countries. Radiologists should be aware of the role of imaging in the diagnosis of this disease and the use of imaging as a guideline for subsequent intervention.

Does the echogenicity of focal liver lesions on baseline gray-scale ultrasound interfere with the diagnostic performance of contrast-enhanced ultrasound?

The objective was to evaluate whether the echogenicity of focal liver lesions (FLLs) on baseline gray-scale ultrasound (US) interferes with the diagnostic performance of contrast-enhanced US (CEUS) for small FLLs. Three-hundred and eighty-eight patients were examined by real-time CEUS using a sulfur hexafluoride-filled microbubble contrast agent. The images of 114 hyperechoic lesions, 30 isoechoic lesions and 244 hypoechoic lesions were reviewed by two blinded independent readers. A five-point confidence level was used to discriminate malignant from benign lesions, and specific diagnoses were made. The diagnostic performances were evaluated by receiver-operating characteristic (ROC) analysis. The diagnostic performances of CEUS on hyperechoic lesions in terms of the areas (Az) under the ROC curve were 0.987 (reader 1) and 0.981 (reader 2), and were 0.987 (reader 1) and 0.984 (reader 2) for iso- and hypoechoic lesions, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 87.0-95.9%, 93.1-100%, 88.6-100%, 70.0-97.1% and 90.0-95.1%, respectively. The echogenicity of FLLs on baseline gray-scale US does not appear to interfere with the diagnostic ability of CEUS for small FLLs.

Real-time contrast-enhanced ultrasound imaging of infected focal liver lesions

OBJECTIVE

The purpose of this study was to investigate the features of infected focal liver lesions on contrast-enhanced ultrasound (CEUS) imaging.

METHODS

Thirty-two hepatic abscesses, 15 infected granulomas, and 6 inflammatory pseudotumors in 53 patients were evaluated with real-time CEUS before awareness of the definitive diagnosis. A 2.4-mL dose of a sulfur hexafluoride-filled microbubble contrast agent was administered by intravenous bolus injection.

RESULTS

The numbers of abscesses with hyperenhancement, isoenhancement, and hypoenhancement in the arterial phase were 26 (81.3%), 5 (15.6%), and 1 (3.1%), respectively. Thirty (93.8%) lesions were irregularly rim enhanced with nonenhanced areas; enhanced septa were shown in 22 (68.8%) lesions; and transient hyperenhancement of liver parenchyma around the lesion was shown in 20 (62.5%). In 31 abscesses with hyperenhancement or isoenhancement in the arterial phase, 25 (80.6%) showed contrast wash-out and changed in appearance to hypoenhancement in the late phase. As for infected granulomas and inflammatory pseudotumors, 16 (76.2%) lesions showed hyperenhancement or isoenhancement in the arterial phase, and all of them were hypoenhanced in the portal and late phases.

CONCLUSIONS

Most infected focal liver lesions showed more rapid contrast wash-out than the surrounding liver parenchyma, which is similar to malignant lesions. Abscesses typically showed features of rim enhancement, enhanced internal septa, nonenhanced central necrotic areas, and transient hyperenhanced liver parenchyma around the lesions. The CEUS appearance of infected granulomas and inflammatory pseudotumors was variable, and a biopsy was necessary for definitive diagnosis.

Inflammatory pseudotumor of the liver: report of eight cases, including three unusual cases, and a literature review

BACKGROUND

Inflammatory pseudotumor (IPT) of the liver is a rare but increasingly recognized tumor-like lesion. This condition is becoming an important differential diagnosis in patients with hepatic space-occupying lesions. This study reports the clinical features of eight cases of IPT of the liver, including the first report of three cases with an unusual associated disease or clinical course.

METHODS

The study sample included cases of IPT diagnosed based on the histopathology in our institution from 1995 to 2004. Clinical events were reported and compared with reports in the literature.

RESULTS

The age of the patients ranged from 28 to 78 years. The most common symptoms were abdominal pain, fever and bodyweight loss. Three patients were diagnosed incidentally. The initial clinical diagnoses were hepatocellular carcinoma in three cases, liver abscess in two cases, metastasis in one case and uncertain nature in two cases. Two cases were associated with preceding endophthalmitis and cholangiocarcinoma, respectively. Two patients had spontaneous lesion regression, but one of these had possible recurrence 10 months later. The other two patients experienced resolution of their lesions following antibiotic treatment. Four patients underwent surgical resection with subsequent recovery.

CONCLUSIONS

The clinical and imaging features of IPT in this small series were found to sometimes mimic those of malignant liver tumors or abscess. Surgical resection was performed in half of the cases. However, IPT of the liver could resolve spontaneously or following antibiotics treatment.

Inflammatory myofibroblastic tumors in the liver: MRI of two immunohistochemically-verified cases

In immunohistochemically-proven hepatic inflammatory myofibroblastic tumors, MRI revealed layered patterns of contrast enhancement during dynamic imaging, consisting of outer hypovascular rind and inner hypervascular stroma and mimicking the imaging features of pyogenic organized abscess with deficient central necrosis in four lesions in two patients. For the outer hypovascular rind, T2-weighted images showed hyperintensity, suggesting immature fibrosis corresponding to the area of arterial hypovascularity and delayed contrast enhancement. The patients' favorable clinical course and imaging findings reflected the benign nature of these lesions, from an infectious origin, despite the phenotypic expression of myofibroblastic proliferation in the hypervascular stroma containing chronic inflammatory cells.

Imagerie des pseudo-tumeurs inflammatoires hépatiques

PURPOSE

To describe the imaging features of inflammatory pseudotumors of the liver.

INTRODUCTION

Inflammatory pseudotumors of the liver are rare benign lesions that may simulate malignancy on imaging studies. Diagnosis is most frequently confirmed after surgical resection of the lesion.

MATERIALS AND METHODS

Retrospective study from 1998 to 2006 of histologically proven cases of inflammatory pseudotumors of the liver. A combination of the following imaging modalities were utilized: US, contrast enhanced US, helical CT and MRI.

RESULTS

A total of seven lesions (mean diameter of 61.4 mm) were detected in 6 patients (mean age of 66 years). Clinical and laboratory results were non-specific. The following imaging studies were available: US in 5 cases, including one with contrast material, CT in 5 cases and MRI in 3 cases. All tumors were hypoechoic on US, with no enhancement after injection of Levovist. The tumors were generally hypodense on noncontrast CT and enhancement, when present, was delayed and moderate. On MRI, the tumors were iso- or slightly hyperintense on T2W images and iso- or slightly hypointense on T1W images with subtle peripheral enhancement on delayed imaging.

CONCLUSION

The differential diagnosis of inflammatory pseudotumor of the liver should be known to radiologists and could be suggested in a clinical context of chronic inflammatory process in patients with non-specific liver mass showing imaging features of partial fibrosis with delayed enhancement.

Spontaneous regression of inflammatory pseudotumor of the liver: report of three cases

Inflammatory pseudotumor (IPT) of the liver is a rare benign hepatic lesion that sometimes mimics malignant tumors. An accurate diagnosis of IPT is important to avoid unnecessary surgery. We herein report three cases of IPT of the liver that spontaneously regressed and were successfully diagnosed without a surgical resection. Malignant tumors were initially suspected based on the initial imaging findings, including ultrasonography, computed tomography (CT), and magnetic resonance imaging. In particular, a delayed enhancement in the periphery of the masses was observed on dynamic CT scans, similar to the imaging results for metastatic tumors or intrahepatic cholangiocarcinomas. The serum levels of C-reactive protein were elevated in all three patients (6.6, 3.4, and 1.5 mg/dl), while the serum levels of tumor markers were almost within the normal ranges (carcinoembryonic antigen, <5 ng/ml; carbohydrate antigen 19-9, 201, 3, and 14 U/ml). Serial repeated imaging studies over the course of a month showed the spontaneous regression of the hepatic tumors, thus enabling us to make a diagnosis of IPT without a surgical resection. A percutaneous biopsy confirmed the histology in one case. The regression of tumors on repeated images should play a key role in making an accurate diagnosis of IPT.

Multiple inflammatory pseudotumor of the liver, mimicking cholangiocarcinoma with tumor embolus in the hepatic vein: report of a case

A 68-year-old Japanese woman complaining of general fatigue and intermittent high fever was admitted to our hospital. Abdominal ultrasonography showed two tumors in the lateral segment of the liver, with soft tissue in the left hepatic vein that was considered to be a tumor embolus. A diagnosis of cholangiocarcinoma was made based on various radiological and laboratory examinations and therefore a surgical resection was performed. Microscopically, the tumor consisted of inflammatory cells, which had aggressively invaded the hepatic vein and Arantius' duct. The pathological diagnosis was inflammatory pseudotumor (IPT) that had invaded the hepatic vein. Although many cases of hepatic IPT have been previously reported, cases of hepatic IPT massively invading the hepatic vein are very rare as far as we could determine, based on a literature search. We herein report this case and discuss the diagnosis and treatment regarding hepatic IPT with massive venous invasion.

Inflammatory pseudotumor of the liver masquerading as hepatocellular carcinoma after a hepatitis B virus infection: Report of a case

We report a rare case of hepatic inflammatory pseudotumor (IPT) after a hepatitis B virus (HBV) infection. Early contrast enhancement on computed tomography (CT) with a washout phenomenon at the delayed phase, and depleted Kupffer cell function on superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging (MRI) suggested hepatocellular carcinoma (HCC). However, the lack of a tumor capsule, absence of liver cirrhosis, and normal serum levels of alpha-fetoprotein and PIVKA-II (protein induced by vitamin K absence; descarboxyprothrombin) contradicted this diagnosis. We excised the tumor to exclude malignancy, and the histopathological diagnosis was IPT. Recent evidence suggests that this entity has changed from an extremely rare pathology to an established disease. Thus, IPT should be considered in the differential diagnosis of a liver mass with an infectious-inflammatory antecedent. Although surgery is not mandatory, surgical removal is recommended if there is a possibility of malignancy. Further investigations are warranted to elucidate the mechanisms of IPT developing after an HBV infection.

Biliary Inflammatory Pseudotumor: Imaging Features in Seven Patients

OBJECTIVE

Hepatic biliary pseudotumor is a benign, rare, and poorly understood tumor that is typically diagnosed after aggressive surgical intervention. The purpose of this report is to describe the clinical and imaging features of this tumor in seven patients.

CONCLUSION

Although secondary clinical features may rarely suggest inflammatory pseudotumor, the typical presenting symptom--painless obstructive jaundice--is indicative of malignancy. The imaging appearance of hepatic hilar biliary pseudotumor is also indistinguishable from that of cholangiocarcinoma.

A rare case of inflammatory pseudotumour of the submandibular lymphnode

Inflammatory pseudotumour (IPT), also known as inflammatory myofibroblastic tumour, is a rare cause of benign cervical lymphadenopathy. In its acute clinical presentation it mimics malignant and infective causes of cervical lymphadenopathy. The combined clinical history, histopathological findings, and imaging features of an infiltrating soft-tissue mass should lead to the possibility of IPT. Radical surgery should be avoided before there is histological proof of a malignant tumor.

Recurrent pyogenic cholangitis due to chronic infestation with Clonorchis sinensis (2006: 8b)

Recurrent pyogenic cholangitis is a common disease in Southeast Asia, where an association with the liver fluke Clonorchis sinensis is postulated. It is characterised by repeated attacks of cholangitis with multiple recurrences of bile duct stones and strictures. We present a case of recurrent pyogenic cholangitis due to chronic infestation with Clonorchis sinensis in a young Asian immigrant, describing its radiological appearances and also therapeutic strategies with a review of additional examples from the literature.

A case of hepatic inflammatory pseudotumor identified by FDG-PET

A 53-year-old man with a history of nausea and elevated liver functions presented to our clinic. A CT scan showed a small tumor in the right lobe of the liver. Fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography confirm abnormal metabolic activity with a high standardized uptake value of 7.3 in the lesion. These findings could indicate a malignancy such as well-differentiated hepatocellular carcinoma or cholangiocarcinoma, or a benign lesion such as hepatic abscess. He was diagnosed by histopathological examination as having an epithelioid granuloma with many inflammatory cells. This is the rare report of hepatic inflammatory pseudotumor featuring markedly increased 18F-FDG uptake.

CT Differentiation of cholangiocarcinoma from periductal fibrosis in patients with hepatolithiasis

OBJECTIVE

The objective of our study was to determine useful CT findings for differentiating cholangiocarcinoma from periductal fibrosis in patients with hepatolithiasis.

MATERIALS AND METHODS

CT images of 30 patients with hepatolithiasis and pathologically proven cholangiocarcinoma (n = 14) or periductal fibrosis (n = 16) were retrospectively reviewed. Helical CT scans were obtained before, 30 seconds after, and 65 seconds after the start of contrast material injection. Analysis of CT findings included evaluation for the presence of periductal soft-tissue density, bile duct wall thickening at the stricture site, ascites, portal vein obliteration, lymph node enlargement, and a duct stone; assessment of the degree of ductal dilatation; and evaluation of the enhancement pattern of periductal lesions, thickened ductal wall, and hepatic parenchyma. The CT attenuation coefficients of the thickened ductal wall and adjacent normal-looking bile duct were measured on images obtained during each phase. Among these findings, statistically significant variables were determined using the Fisher's exact test and Student's t test. Sensitivity and specificity values of the CT criteria were also calculated.

RESULTS

The presence of periductal soft-tissue density (p = 0.002), higher enhancement of the duct than adjacent bile duct on portal venous phase images (p = 0.008), ductal wall thickening (p = 0.026), portal vein obliteration (p = 0.031), and lymph node enlargement (p = 0.031) were found to be the significant findings for differentiating cholangiocarcinoma from fibrosis in patients with hepatolithiasis. When any two or more of these five criteria were used in combination, we could identify 100% of the patients with cholangiocarcinoma but only 12.5% of the patients with fibrosis.

CONCLUSION

Cholangiocarcinoma in patients with hepatolithiasis can be diagnosed using specific CT criteria.