Hypereosinophilic syndrome: imaging findings in patients with hepatic involvement

Beyond stroke-uncommon causes of diffusion restriction in the basal ganglia

In the emergency setting, a regional area of restricted diffusion involving the basal ganglia typically represents an acute infarct due to small vessel occlusion. However, it is important to consider additional differentials, specifically systemic causes. This article will review anatomy of the basal ganglia and pertinent associated vasculature, followed by other entities that can be a cause of restricted diffusion. These include hemolytic uremic syndrome, hypereosinophilic syndrome, fat embolism, meningitis, and hypoxic-ischemic injury. It is important to recognize presenting findings in these conditions, as the radiologist may be the first to give an accurate diagnosis or prompt additional testing.

Hepatic Lesions that Mimic Metastasis on Radiological Imaging during Chemotherapy for Gastrointestinal Malignancy: Recent Updates

During chemotherapy in patients with gastrointestinal malignancy, the hepatic lesions may occur as chemotherapy-induced lesions or tumor-associated lesions, with exceptions for infectious conditions and other incidentalomas. Focal hepatic lesions arising from chemotherapy-induced hepatopathies (such as chemotherapy-induced sinusoidal injury and steatosis) and tumor-associated eosinophilic abscess should be considered a mimicker of metastasis in patients with gastrointestinal malignancy. Accumulating evidence suggests that chemotherapy for gastrointestinal malignancy in the liver has roles in both the therapeutic effects for hepatic metastasis and injury to the non-tumor bearing hepatic parenchyma. In this article, we reviewed the updated concept of chemotherapy-induced hepatopathies and tumor-associated eosinophilic abscess in the liver, focusing on the pathological and radiological findings. Awareness of the causative chemo-agent, pathophysiology, and characteristic imaging findings of these mimickers is critical for accurate diagnosis and avoidance of unnecessary exposure of the patient to invasive tissue-based diagnosis and operations.

Production of interleukins 4 and 10 in children with hepatic involvement in the course of Toxocara spp. infection

Toxocara spp. infestations present with a wide spectrum of symptoms, from general inflammation of internal organs with eosinophilic granuloma formulation through ocular or brain involvement. There is also an asymptomatic form. The known factors that influence the clinical form of the disease are the intensity of the infestation, the localization of the larvae, the age of the patient, the efficiency of the immune system and the history of reinfection. The aim of our study was to evaluate the production of interleukins 4 (IL-4) and 10 (IL-10) in children in the course of Toxocara spp. infections with hepatic involvement. The analysis of peripheral leucocytes, eosinophils, immunoglobulin E, and IL-4 and IL-10 concentrations presented significantly higher values in children with radiologically confirmed liver granuloma than in uncomplicated hepatomegaly. Based on statistical analysis, we confirmed the IL-4/IL-10 ratio variation in the analysed groups: patients with liver lesions showed a ratio of <1, while children without granulomas had a ratio of >2. The relevant analysis confirmed a positive statistical correlation in both seropositive groups for IgE and IL-4, and only in the granuloma group for IgE and IL-10.

Hepatic visceral larva migrans, a resilient entity on imaging: Experience from a tertiary liver center

INTRODUCTION

Hepatic visceral larva migrans (VLM) is an uncommon parasitic manifestation seen in the liver. It presents as coalescing, conglomerated, or solitary abscess cavities in the liver on imaging. We conducted a retrospective clinico-radiological analysis of 24 patients with biopsy proven VLM who were reviewed and followed up at our tertiary liver institute over a period of 4 years.

MATERIALS AND METHODS

The study was performed to correlate the radiological features and imaging response to therapy for hepatic VLM. The disease course, imaging findings, progressive, absolute eosinophil counts (AEC), hydatid serology, and the extent of radiological regression of the liver lesions, on follow-up were analyzed.

RESULTS

Imaging showed a diagnostic accuracy of 42%. Hydatid serology was positive in 46% patients before starting treatment. The median pretreatment AEC of 507 showed a significant posttreatment AEC decline to median value of 117. The Wilcoxon signed ranks test showed significant decline in the AEC (P < 0.001). Radiological regression was present in all lesions. However, patients showed residual abscesses on imaging, up to 2 years on follow-up.

CONCLUSION

This study reveals that AEC has a significant predictive value in diagnosis and as a marker for disease regression. Complete radiological resolution of hepatic lesions does not correlate with total clinical remission. This finding warrants the need for further studies to look into the role of prolonged medical therapy or surgery as an alternate to current therapy module in cases of hepatic visceral larva abscesses.

Visceral larva migrans syndrome: analysis of serum cytokine levels in children with hepatic lesions confirmed in radiological findings

Human toxocariasis is a helminth zoonosis resulting from accidental infection of humans by the roundworms Toxocara canis (T. canis) and cati (T. cati). The infection occurs in five forms: systemic (VLM), ocular, neurological, covert and asymptomatic. The aim of this study was to characterize the radiological and immunological findings in hepatic inflammation during the course of systemic infection by Toxocara sp. in children. Fifteen children, 2 to 17 years of age, with serological diagnosis of T. canis infection underwent abdominal ultrasonography and computer tomography (CT). Eosinophil counts, immunoglobulin E titres, interleukins IL-1α, IL-4, Il-6, IL-10 and interferon gamma were measured for all patients. Abdominal ultrasound revealed multiple hypoechoic areas in the livers of all patients. On the CT images, the hepatic lesions were seen as multiple, ill-defined, oval low-attenuating nodules that measured 6 to 9 millimetres in diameter. The nodules were usually best seen in the portal venous phase and were not seen on arterial-phase images. Significant intergroup differences were observed in the concentrations of IL-1α, IL-4, IL-6 and IL-10. The level of IFN-γ was not significantly elevated in patient sera relative to controls. The analysis shows that the production of anti-inflammatory cytokines is insufficient for granuloma formation in children presenting liver lesions in the course of VLM.

FELD better not thinking of metastases only when liver lesions appear after bleomycin-based treatment for non-seminoma testis from metastases

BACKGROUND

Bleomycin has become an integral part of chemotherapy in patients with germ-cell tumors. One of the most feared side effects is bleomycin-induced pneumonitis. In patients with mild or moderate BIP, radiological signs disappear almost completely within nine months after discontinuation of bleomycin treatment.

CASE PRESENTATION

We present a patient with a history of non seminoma of the testis and bleomycin-induced pneumonitis. During follow-up, regression of the hypothesis of eosinophilic migration to the liver after regression of bleomycin-induced pneumonitis is highly suspicious based on transient eosinophilia and focal eosinophilic liver disease.

CONCLUSION

As follow up may consist of CT scanning in germ-line tumor patients, transient eosinophilic liver lesions reported during regressive bleomycin-induced pneumonitis should not be presumed automatically as metastatic tumor relapse and require further sequential imaging and pathological examination.

Eosinophilic granulomatous gastrointestinal and hepatic abscesses attributable to basidiobolomycosis and fasciolias: a simultaneous emergence in Iraqi Kurdistan

Background

Deep eosinophilic granulomatous abscesses, as distinguished from eosinophilic subcutaneous abscesses, are rare. Most reports are from the Far-East and India where the most commonly attributed cause is Toxocara. Sulaimaniyah in Northeastern Iraq has experienced an outbreak of eosinophilic granulomatous liver and gastrointestinal (GI) abscesses beginning in 2009. The purpose of this study was to determine the etiology and guide treatment.

Methods

The study was an ongoing investigation of patients having a histopathologic diagnosis of eosinophilic granulomatous abdominal abscesses in Sulaimaniyah hospitals from May 2009 to August 2012. Tissues were examined for organisms, and Enzyme Linked Immunoabsorbent Assays (ELISA) were performed for serum antibodies to Fasciola hepatica, Toxocara, and Echinococcus granulosus.

Results

Fourteen patients had granulomatous inflammation surrounding a central necrotizing eosinophilic exudate identified in surgical pathology specimens from abdominal surgeries. Two children and four adults had abscesses that formed GI masses. These patients included a 39 year old male with oropharyngeal and transverse colon disease, and a 48 year old male with liver and GI abscesses. All sites demonstrated a Zygomycete fungus surrounded by eosinophilic Splendori-Hoeppli material consistent with basidiobolomycosis. Five of the six patients with fungal disease were treated by surgery and 4 to 7 months of itraconozol. One child died of intestinal perforation while receiving IV amphotericin B; two adults required additional surgery for recurrent GI obstruction. Eight patients had isolated liver abscesses with no organisms identified by histopathology: ELISA results for F. hepatica were positive for five, borderline for one, and negative for two patients. These eight patients were treated for fascioliasis by surgical resection of localized abscesses and albendazol. One patient serologically positive for F. Hepatica was found to have a common duct fluke two years after initial diagnosis. Serological testing for Toxocara and Echinococcus granulosus was negative in all 14 patients.

Conclusions

Basidiobolomycosis and F. hepatica are implicated as the cause of abdominal eosinophilic granulomatous abscesses in 12 of 14 patients identified over a period of 40 months in northern Iraq. Treatment was complicated by chronic biliary tract disease in fascioliasis and perforation and recurrent intestinal obstruction with basidiobolomycosis.

Differentiating focal eosinophilic liver disease from hepatic metastases using unenhanced and gadoxetic acid-enhanced MRI

PURPOSE

To examine the differential features of focal eosinophilic liver disease (FELD) from liver metastases on gadoxetic acid-enhanced MRI.

MATERIALS

Twenty patients with 41 FELD and 20 patients with 55 metastases were enrolled in this study. Liver MRI consisted of precontrast 2D T1-weighted image (T1WI) and gadoxetic acid-enhanced 3D T1WI (arterial, portal, 20 min hepatocyte-selective phases), and a postcontrast T2WI. Images were analyzed for the margin and shape of the lesions; lesion conspicuity on T1- and T2WI; signal intensity of the lesions on 3D T1WI; presence of rim enhancement and misty signs; and presence of significant smaller lesions on the unenhanced T1WI (<50%) compared to hepatocyte phase image.

RESULTS

Univariate analysis revealed the following significant parameters to favor FELD: a fuzzy margin, irregular shape, subtle signal intensity changes on T1- and T2WI, absence of target signs on the hepatocyte phase image, presence of misty signs, and size discrepancies on T1WI and hepatocyte phase images. Multivariate analysis revealed only a significantly smaller lesion size on T1WI compared to hepatocyte phase images to be predictive of FELD.

CONCLUSION

A significantly smaller lesion size on T1WI relative to hepatocyte phase image is the best predictor for identifying FELD on gadoxetic acid-enhanced MRI.

Differentiating focal eosinophilic infiltration from metastasis in the liver with gadoxetic acid-enhanced magnetic resonance imaging

Objective

To determine the most useful findings of gadoxetic acid-enhanced 3.0 Tesla (T) MRI for differentiating focal eosinophilic infiltration (FEI) from hepatic metastasis with verification of their usefulness.

Materials and Methods

Pathologically or clinically proven 39 FEIs from 25 patients and 79 hepatic metastases from 51 patients were included in the study. Gadoxetic acid-enhanced 3.0T MRI was performed in all cancer patients. Size differences measured between T2-weighted and hepatobiliary-phase images for lesions > 1 cm and morphologic findings (margin, shape, signal intensity on T1- and T2-weighted images, enhancement pattern on dynamic images, and target appearance on hepatobiliary-phase images) were compared between two groups via Student's t test as well as univariate and multivariate analyses. Diagnostic predictive values of two observers for differentiating two groups were assessed before (session 1) and after (session 2) recognition of results.

Results

Mean size difference (2.1 mm) in FEIs between the two images was significantly greater than for metastases (0.7 mm) (p < 0.05). An ill-defined margin and isointensity on T1-weighted images were independently significant morphologic findings (p < 0.05) for differentiating the two groups. All observers achieved a higher diagnostic accuracy in session 2 (97% and 98%) than session 1 (92% and 89%) with statistical significance in observer 2 (p < 0.05). All observers had significantly higher sensitivities (95%) and negative predictive values (NPVs) (98%) in session 2 than in session 1 (sensitivity, 74% in two observers; NPV, 89% and 88%) (p < 0.05).

Conclusion

With the size change, an ill-defined margin and isointensity on T1-weighted images are the most useful findings for differentiating FEI from hepatic metastasis on gadoxetic acid-enhanced 3.0T MRI.

A Case of Hypereosinophilia-Associated Multiple Mass Lesions of Liver Showing Non-Granulomatous Eosinophilic Hepatic Necrosis

Hypereosinophilic syndrome (HES) is defined by elevation more than 1.5×10⁹/L of presence of a peripheral blood count, evidence of organ involvement, and exclusion of secondary eosinophilia such as allergic, vasculitis, drugs, or parasite infection and also clonal eosinophilia. We present the HES case with hepatic involvement. The patient is 70-year-old male. He complained fever and back pain. Blood examination showed marked peripheral eosinophilia, elevation of transaminase and biliary enzymes. Multiple irregular mass lesions of the liver were pointed out by CT and MRI. The liver biopsy was done for differentiation from malignancy. In parenchyma, hepatic necrotic lesion was observed accompanying severe eosinophilic infiltration with Charcot-Leyden's crystals. There was granulomatous reaction. He was diagnosed as HES and got recovery due to steroid therapy. From the review of HES article, the hepatic histology is categorized into four types as below: 1) cholangitis type; 2) chronic active hepatitis type; 3) vasculopathic type, 4) hepatic necrosis type. Our case is classified in hepatic necrosis type. This type seems to be important to distinguish malignant tumor and also visceral larva migrans by liver biopsy.

MR findings of focal eosinophilic liver disease using gadoxetic acid

PURPOSE

The purpose of this study was to describe magnetic resonance (MR) findings of focal eosinophilic liver disease using gadoxetic acid (Gd-EOB-DTPA).

MATERIALS AND METHODS

Nineteen patients (M:F=14:5; age range, 26-66 years; mean age, 50 years) with 35 focal eosinophilic liver lesions were included after reviewing the medical records of 482 patients who underwent Gd-EOB-DTPA-enhanced MR imaging (MRI) on a 3.0-T unit between April 2008 and June 2009. The diagnosis of focal eosinophilic liver disease was established by means of percutaneous liver biopsy or surgery and consistent clinical findings. Two radiologists retrospectively reviewed MR images with consensus. Margin, shape and distribution of the lesions were analyzed. We also evaluated signal intensity of focal hepatic lesions on T(1)- and T(2)-weighted images and patterns of enhancement in dynamic contrast study.

RESULTS

The mean diameter of the lesions was 1.7 cm (range, 0.7-6.1 cm). Most of the focal eosinophilic liver lesions [n=31/35 (88.6%)] had poorly defined margins. They were usually isointense or slightly hypointense [n=34/35 (97.2%)] on T(1)-weighted images and hyperintense [n=32/35 (91.4%)] on T(2)-weighted images. Dynamic study showed enhancement (rim or homogeneous) on the arterial phase [n=21/35 (60%)] and hypointensity on the late venous phase [n=31/35 (88.6%)]. All the lesions were hypointense on the hepatobiliary phase images.

CONCLUSION

Focal eosinophilic liver lesions tend to be hyperintense on the arterial phase and hypointense on the late venous phase during dynamic study of Gd-EOB-DTPA-enhanced MRI. Although these findings mimic other focal hepatic lesions, poorly defined margins of the lesions and peripheral eosinophilia might help distinguish focal eosinophilic liver disease from other hepatic lesions.

Focal eosinophilic necrosis on superparamagnetic iron oxide-enhanced MRI

OBJECTIVE

The purpose of our study was to evaluate the usefulness of superparamagnetic iron oxide (SPIO)-enhanced MRI for distinguishing focal eosinophilic necrosis (FEN) from hepatic metastasis.

MATERIALS AND METHODS

Forty-one cases of FEN in 41 patients and 40 hepatic metastases in 40 patients were analyzed on unenhanced and SPIO-enhanced T2-weighted MRI retrospectively. Depending on the extent of the remaining hyperintense area on SPIO-enhanced T2-weighted images compared with the unenhanced images, the lesions were classified into four categories--category 1, less than 25%; category 2, 25-49%; category 3, 50-75%; and category 4, more than 75%--by two independent readers. Contrast-to-noise ratio (CNR) was measured using the same region of interest on unenhanced and SPIO-enhanced T2-weighted images. In three pathologic specimens of FEN, the number of Kupffer cells was compared with that of background hepatic parenchyma.

RESULTS

All metastases were classified as category 4, whereas FEN showed various distributions overall (category 1, 45.2%; category 2, 24.6%; category 3, 13.4%; category 4, 17.1%). FEN showed a decrease in CNR (from 7.9 +/- 5.8 to 6.1 +/- 5.6, p < 0.05), and metastases showed an increase in CNR (from 33.7 +/- 27.0 to 55.0 +/- 44.3, p < 0.05) after SPIO administration. In biopsy specimens, FEN had many more Kupffer cells (174.7 +/- 120.3 cells/high-power field [hpf]) than background hepatic parenchyma (23.7 +/- 9.8 cells/hpf). When using signal loss categories 1, 2, or 3 or CNR decrease, the accuracy of SPIO enhancement was 88.3%.

CONCLUSION

Unlike hepatic metastases, most of the cases of FEN showed a reduction in the extent of hyperintense area or a decrease in CNR after SPIO administration on the T2-weighted images. Therefore, SPIO-enhanced T2-weighted MRI can help to differentially diagnose FEN from metastases.

Hepatic Visceral Larva Migrans ofToxocara canis: CT and Sonographic Findings

OBJECTIVE

The aim of this study was to describe the CT and sonographic findings of hepatic visceral larva migrans of Toxocara canis.

MATERIALS AND METHODS

Fifty-four patients (44 men, 10 women; age range, 30-80 years; mean age, 53 years) with serologically confirmed visceral larva migrans of Toxocara canis underwent evaluation of the liver with CT (n = 25), sonography (n = 48), or both. Two radiologists used consensus for retrospective evaluation of CT and sonographic findings. Correlation between the presence and severity of hepatic abnormalities on images and the degree of peripheral eosinophilia was assessed.

RESULTS

Seventeen (68%) of 25 patients who underwent CT had single or multiple ill-defined, oval or elongated, small, low-attenuating lesions in the liver. Eighteen (38%) of 48 patients who underwent sonography had single or multiple small, poorly defined, oval or elongated, hypoechoic scattered focal lesions in the liver. In the 19 patients who underwent both CT and sonography, the two techniques had no significant difference in rate of detection of hepatic lesions (p = 0.375, McNemar test). The lesion numbers on CT and sonography showed excellent linear correlation (r = 0.844, p = 0.001) by Pearson's correlation test. An independent samples t test showed that eosinophil count and percentage in the peripheral blood were significantly higher in patients with hepatic lesions on CT and sonography than in patients without lesions.

CONCLUSION

CT and sonographic findings of hepatic visceral larva migrans of T. canis are multiple, ill-defined, oval or elongated, small, nodular lesions scattered in the liver parenchyma. The presence of hepatic lesions on images was associated with higher peripheral eosinophil count and percentage.

Multiple hepatic nodules: rare manifestation of clonorchiasis

A 38-year-old man was admitted due to intermittent right upper quadrant pain for 1 month. Leukocytosis with marked eosionphilia and elevated serum alkaline phosphatase were noted. Stool examinations revealed no parasites or ova. Ultrasonography and computed tomography disclosed multiple hepatic tumors. Biopsy of the hepatic tumor was performed due to non-conclusive imaging studies and revealed eosinophil infiltration in portal areas only. Endoscopic retrograde cholangiography showed mild dilatation with irregularity of bilateral intrahepatic ducts, compatible with chronic cholangitis. Bile was aspirated and biliary lavage with normal saline was performed during endoscopy-guided biliary cannulation. Microscopic examination of the aspirate showed the characteristic ova of Clonorchis sinensis. The patient received Praziquantel therapy for 1 day. Abdominal pain reduced in intensity gradually. Eosinophilia and multiple hepatic lesions resolved after adequate treatment of Clonorchis sinensis. The rare manifestation of multiple hepatic tumors in Clonorchis sinensis should be differentiated from other primary or metastatic neoplasms, while biliary lavage for parasite ova is a valuable diagnostic tool when stool examination is negative.

Contrast-enhancing hepatic eosinophilic abscess during the hepatic arterial phase: a mimic of hepatocellular carcinoma

OBJECTIVE

Our objective was to review CT, MR, angiographic, and sonographic images obtained in patients with histopathologically proven contrast-enhancing hepatic eosinophilic abscesses during the hepatic arterial phase.

CONCLUSION

On CT, MR, and angiographic images, eosinophilic abscess in the liver can show contrast enhancement during the hepatic arterial phase. If patients have peripheral hypereosinophilia or are at low risk for hepatocellular carcinoma or hepatic metastasis, those with small arterial-enhancing hepatic nodules need further preoperative evaluation, such as a sonographically guided biopsy.

Eosinophilic Hepatic Necrosis

OBJECTIVE

To compare the findings of magnetic resonance (MR) imaging with those of computed tomography (CT) of focal liver lesions related to peripheral eosinophilia.

METHODS

For 12 patients with peripheral eosinophilia (>7%) examined with hepatic MR imaging and CT, 52 focal hepatic lesions larger than 0.5 cm, including 31 lesions simultaneously found on the 2 imaging modalities, were subjected to a comparative analysis of their imaging features.

RESULTS

The total number of lesions distinguished from background liver was 39 (75%) on MR imaging and 44 (85%) on CT scans. On arterial phase images of 10 patients with comparable data, homogeneously hyperintense lesions were demonstrated more frequently (P = 0.006) on MR imaging (16 [50%] of 32 lesions) than on CT scans (4 [13%] of 32 lesions). Only 7 (22%) of the 32 hypoattenuating lesions on portal phase CT were depicted as hypointense lesions on portal phase MR images in 12 patients. On delayed phase images in 8 patients, the number of hyperintense lesions on MR images (9 [56%] of 16) was greater (P = 0.077) than that seen on the CT scans (4 [25%] of 16).

CONCLUSIONS

For many focal hepatic lesions related to peripheral eosinophilia, dynamic MR imaging more easily demonstrates lesional enhancement on arterial and delayed phases than CT scans. Because of the higher degree of lesional enhancement of MR imaging compared with CT, the lesion-to-liver contrast may not be sufficient to distinguish the lesion from the background liver, resulting in decreased sensitivity of portal phase dynamic MR imaging.

MRI Findings of Focal Eosinophilic Liver Diseases

OBJECTIVE

The purpose of this study was to describe the MRI findings of focal eosinophilic infiltration and eosinophilic abscess of the liver.

CONCLUSION

MRI shows characteristic findings of focal eosinophilic liver disease that can be helpful in differentiating lesions of focal eosinophilic liver disease from other focal liver lesions. In addition, eosinophilic abscess and focal eosinophilic infiltration showed different MRI findings from each other.

Focal Eosinophilic Necrosis Versus Metastasis in the Liver: The Usefulness of Two-Phase Dynamic CT

OBJECTIVE

The purpose of our study was to evaluate the usefulness of dual-phase dynamic CT in the differentiation of focal eosinophilic necrosis of the liver and metastasis.

CONCLUSION

Undetected isoattenuating lesions on arterial phase images that have an indistinct margin, a nonspherical shape, and a homogenous enhancement pattern on portal venous phase images suggest focal eosinophilic necrosis rather than metastasis. Two-phase dynamic CT was found to be useful at differentiating focal eosinophilic necrosis from metastasis.

MR Findings in Eosinophilic Infiltration of the Liver

OBJECTIVE

This study describes the findings of magnetic resonance imaging (MRI) of focal eosinophilic infiltration of the liver.

METHODS

Contrast-enhanced MR images of 8 patients with focal hepatic eosinophilic infiltration were reviewed retrospectively. We evaluated the signal intensity of focal lesions in T1-weighted and T2-weighted images and the pattern of enhancement in a dynamic contrast study.

RESULTS

A total 22 focal hepatic lesions were observed; the lesions were isointense (55%) or hypointense (45%) on T1-weighted images and isointense (14%) or hyperintense (86%) on T2-weighted images. The arterial phase of the contrast study revealed 11 hyperintense lesions (50%). During the portal and delayed phases, 18 (82%) and 17 lesions (77%) were hyperintense, respectively.

CONCLUSION

The focal eosinophilic infiltrations showed homogeneous enhancement in the portal and delayed phases in the dynamic contrast MR study. These findings should help to distinguish focal eosinophilic infiltration, especially from metastasis in patients with malignancy.

Concurrent Focal Hepatic and Splenic Lesions

Although medical literature and differential diagnoses discussions tend to be organ specific, systemic diseases more commonly manifest with multi-organ involvement. Detection of dual organ involvement combined with clinical history narrows the differential to provide a more specific diagnosis. Two organs closely linked are the liver and the spleen. Many processes affect both of these organs through their common denominator, the reticuloendothelial system (RES). This pictorial essay reviews the wide spectrum of benign and malignant pathologies to be considered when computed tomography (CT) demonstrates concurrent focal disease in the liver and spleen.

Focal eosinophilic infiltration of the liver mimicking hepatocellular carcinoma

Focal eosinophilic infiltration is a rare disease entity that in patients with malignancies may mimic malignant hepatic nodules. We describe two cases in which focal eosinophilic infiltration of the liver, as well as primary liver cancer, occurred. In these patients, imaging findings similar to those observed in hepatocellular carcinoma (HCC) were noted: Enhancement at dynamic magnetic resonance (MR) imaging substantially increased perfusion at computed tomography during hepatic arteriography (CTHA) and a perfusion defect at computed tomography during arterial portography (CTAP).

Focal eosinophilic necrosis of the liver in patients with underlying gastric or colorectal cancer: CT differentiation from metastasis

OBJECTIVE

To determine the helical CT findings which help differentiate between focal eosinophilic necrosis (FEN) of the liver and metastasis in patients with underlying gastric or colorectal cancer.

MATERIALS AND METHODS

In 21 patients with underlying gastric and colorectal cancer examined during a recent 18-month period, the presence of FEN (n=90) was proven at CT. The diagnosis was verified by biopsy in eight patients and by the transient nature of the findings related to peripheral eosinophilia (>10%) in the remainder. For comparison, 20 consecutive patients with pathologically proven hepatic metastasis from gastric or colorectal cancer (n=158) were selected. Single-phase helical CT images (7-mm collimation, pitch 1:1) were independently analyzed in a random order by two blinded readers. The parameters evaluated included the margin (depicted border, fuzzy), shape (spherical, non-spherical), attenuation (subtle hypoattenuation, hypoattenuation), and the presence or absence of rim enhancement.

RESULTS

FEN far more frequently showed a fuzzy margin (81%, 84%), subtle hypoattenuation (89%, 91%), and a non-spherical shape (84% for both readers) than metastasis, for which the respective findings were 6%, 22%; 20%, 39%; and 15%, 23%. Rim enhancement was seldom found in FEN (0%, 2%), but was recognized by both readers in 40% of metastases. For all parameters, the results were statistically significant (p < .01), and showed that both readers correctly differentiated FEN from metastasis in 78% of the patients (32/41). Interobserver agreement was, in addition, excellent (kappa = 0.66).

CONCLUSION

When focal hepatic lesions with a fuzzy margin, non-spherical shape and subtle hypoattenuation without rim enhancement are found, the possibility of FEN should be considered even in patients with underlying gastrointestinal malignancy.

Hypereosinophilic syndrome: CT findings in patients with hepatic lobar or segmental involvement

OBJECTIVE

The purpose of this study was to describe the CT findings of hepatic hypereosinophilic syndrome in which hepatic lobes or segments were involved.

MATERIALS AND METHODS

Seven patients with hypereosinophilic syndrome with hepatic lobar or segmental involvement were included in our study. In all seven, diagnosis was based on liver biopsy and the results of corticosteroid treatment. CT findings were retrospectively reviewed by three radiologists, who reached a consensus. Biopsy specimens were examined, with special reference to portal and periportal inflammation.

RESULTS

CT demonstrated well-defined, homogeneous or heterogeneous low attenuation with a straight margin limited to a hepatic lobe (n = 2), segments (n = 3), or subsegments (n = 2), particularly during the portal phase. Where there was subsegmental involvement, lesions were multiple, ovoid or wedge-shaped, and showed low attenuation. In two patients with lobar or segmental involvement, segmental portal vein narrowing was observed. Histopathologic examination disclosed eosinophilic infiltration in the periportal area, sinusoids and central veins, as well as portal phlebitis.

CONCLUSION

Hypereosinophilic syndrome may involve the presence of hepatic lobar, segmental, or subsegmental low-attenuated lesions, as seen on CT images. Their presence may be related to damage of the liver parenchyma and to portal phlebitis.