Clinical characteristics that distinguish eosinophilic organ infiltration from metastatic nodule development in cancer patients with eosinophilia

Simple Pulmonary Eosinophilia Mimicking Lung Metastases on 18 F-FDG PET/CT

ABSTRACT

A 72-year-old man with pancreatic tail cancer underwent distal pancreatectomy and splenectomy 1 year ago. Routine postoperative follow-up CT detected multiple pulmonary nodules. 18 F-FDG PET/CT showed multiple FDG-avid nodules in the bilateral lungs, which highly suggested the possibility of lung metastases of pancreatic cancer. Finally, the bronchoalveolar lavage fluid and pathology confirmed the diagnosis of simple pulmonary eosinophilia.

Absolute eosinophil count may be an optimal peripheral blood marker to identify the risk of immune-related adverse events in advanced malignant tumors treated with PD-1/PD-L1 inhibitors: a retrospective analysis

Background

This study aimed to investigate the predictive values of serum biomarkers including absolute eosinophil count (AEC), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) with respect to immune-related adverse events (irAEs) during anti-PD-1/PD-L1 inhibitor treatment in patients with advanced malignant tumors.

Methods

We retrospectively analyzed 95 patients with advanced cancer who were treated with anti-PD-1/PD-L1 inhibitors from January 1, 2017, to May 1, 2020, in our cancer center. We then analyzed associations between irAEs and anti-PD-1/PD-L1 inhibitor responses and evaluated the predictive values of serum biomarkers with respect to the risk of irAEs.

Results

The incidence of irAEs was 55.8%. There were no statistically significant differences between the irAEs and no-irAEs groups in an objective response rate (ORR) or disease control rate (DCR). However, landmark analysis showed that the irAEs group had better survival after 120 days following the initiation of anti-PD-1/PD-L1 inhibitor treatment, compared with the no-irAEs group. The incidences of irAEs were greater in the high-AEC and low-NLR groups than in the low-AEC and high-NLR groups. Univariate logistic analysis showed that low NLR, ECOG performance status (0–1), and high AEC were risk factors for irAEs. Multivariate logistic analysis showed that high AEC and good ECOG performance status were independent predictors for irAEs.

Conclusions

irAEs may be associated with a survival benefit. Baseline AEC is a strong predictor of irAEs in patients undergoing treatment with anti-PD-1/PD-L1 inhibitors.

Eosinophilic Disorders of the Gastrointestinal Tract and Associated Abdominal Viscera: Imaging Findings and Diagnosis

Eosinophilic gastrointestinal disorders (EGIDs) are inflammatory conditions of the gastrointestinal tract that are characterized by tissue eosinophilia and end-organ dysfunction or damage. Primary EGIDs are associated with atopy and other allergic conditions, whereas secondary EGIDs are associated with underlying systemic diseases or hypereosinophilic syndrome. Within the spectrum of EGIDs, eosinophilic esophagitis is the most prevalent. Eosinophilic gastroenteritis and eosinophilic colitis are relatively uncommon. Eosinophilic infiltration of the liver, biliary tree, and/or pancreas also can occur and mimic other inflammatory and malignant conditions. Although endoscopic evaluation is the method of choice for eosinophilic esophagitis, radiologic evaluation of the esophagus plays an important role in the assessment of disease severity. CT and MR enterography are the modalities of choice for demonstrating specific forms of eosinophilic gastroenteritis. CT and MRI are important in the detection of abdominal visceral involvement in EGIDs. Diagnosis is often challenging and relies on symptoms, imaging findings, histologic confirmation of tissue eosinophilia, and correlation with peripheral eosinophilia. Imaging is crucial for identifying characteristic organ-specific findings, although imaging findings are not specific. When promptly treated, EGIDs usually have a benign clinical course. However, a delayed diagnosis and associated surgical interventions have been associated with morbidity. Therefore, a radiologist's knowledge of the imaging findings of EGIDs in the appropriate clinical settings may aid in early diagnosis and thereby improve patient care. An overview of the clinical features and imaging findings of EGIDs and the eosinophilic disorders of associated abdominal viscera is provided. Online supplemental material is available for this article. ^©RSNA, 2022.

Focal eosinophilic infiltration of the liver, benign or malignant?

Focal eosinophilic infiltration (FEI) of the liver shares imaging characteristics with malignant hepatic lesions but should be suspected when concomitantly observing eosinophilia. While in itself benign, the cause of FEI should be sought and treated.

Hepatic Eosinophilic Abscess Associated with Sigmoid Colon Cancer

The clinical course of hepatic eosinophilic abscess (HEA) induced by malignant tumors is not well-known; however, it is considered to be a benign hepatic lesion. HEA is difficult to diagnose by imaging alone and a pathological examination is generally needed, particularly in patients with malignant tumors, because the radiological findings can be similar to those of metastasis. We report a case of multiple HEAs with eosinophilia and sigmoid colon cancer that was difficult to diagnose without a pathological examination. After the resection of the sigmoid colon cancer, the patient's eosinophilia was quickly ameliorated and the HEAs disappeared within 6 months.

CT and MRI findings in focal eosinophilic infiltration of the liver

OBJECTIVES

To investigate the findings of computed tomography (CT) and magnetic resonance imaging (MRI) of focal eosinophilic infiltration (FEI) of the liver.

METHODS

A retrospective study including 29 patients with confirmed FEI of the liver was performed. We evaluated the lesions' number, distribution, size, shape, margin, attenuation or signal intensity characteristics, the enhancement pattern, and some special features. Spearman correlation analysis was used to analyze the correlation between the number of lesions and the eosinophil counts in peripheral blood.

RESULTS

In all, 108 lesions were detected in 29 cases, including two cases with single lesion and the remaining 27 cases with multiple lesions. The mean size of all lesions was 34 mm (range, from 3 to 61 mm). 95 (88%) lesions were located in subcapsular parenchyma or surrounding the portal vein. Most (66%) subcapsular lesions were wedge shaped and all lesions surrounding portal vein were round shaped. However, the hepatic parenchymal lesions were irregular or round shaped. All lesions showed ill-defined margins. On pre-contrast CT images, the lesions showed slightly low attenuation or iso-attenuating. On T1-weighted and T2-weighted images, the lesions were slightly iso-/hypointense and hyperintense, respectively. A total of 23 (79.3%) cases were gradually enhanced. Branches of portal vein went through the lesions in all cases; 12 had 'stripe sign' and 16 had 'halo ring sign.' Spearman analysis indicated a significant correlation between the number of lesions and the increased eosinophils in peripheral blood (r = 0.627, p = 0.0003).

CONCLUSIONS

Special CT and MRI features and increased eosinophils may strongly suggest the diagnosis of FEI of the liver.

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.

Eosinophilic Liver Disease Mimicking Hepatic Metastases

In rare cases of hypereosinophilic syndrome, nodular lesions of liver due to infiltration of eosinophilic granulocytes has been described. In such cases, a computed tomography of the abdomen could mimic a metastasizing disease while a spontaneous regression of the lesions can be expected. We will present such a case and discuss how this misdiagnosis can be avoided.

A Rare Right Ventricular Involvement of Eosinophilic Granulomatosis Demonstrated by Cardiac MRI

BACKGROUND

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare systemic vasculitis with a prevalence rate of seven per million. Cardiac involvement was reported in 20-50%, yet with improved diagnostic methods, the frequency of cardiac involvement is expected to be even higher. It can result in significant morbidity and mortality, accounting for about 50% of death. Cardiac magnetic resonance (CMR) imaging is used to evaluate the myocardium, valves, coronary arteries, pericardium, also to assess cardiac structure and function. Perfusion study allows tissue characterisation with a suggestive pattern of late gadolinium enhancement.

CASE REPORT

We report a rare case of EGPA in a 54-year-old male patient who presented with fever, sore throat and dizziness. Echocardiography showed a filling defect at the apex of the right ventricle (RV). CMR findings suggested the diagnosis of EGPA by demonstrating an impressive lesion at RV apex with the typical 3-layer appearance and thrombus formation. Post-gadolinium subendocardial hyperenhancement suggested focal involvement at the inferolateral wall of the left ventricle. Computed Tomography (CT) was done to rule out calcific or soft plaques of the coronary arteries, small vessel vasculitis and small aneurysm. CT scan showed a low-attenuation lesion at the inner wall of the right ventricle. In the lungs, bilateral interstitial changes and bilateral cystic bronchiectases were found. Under appropriate treatment, the patient improved clinically.

CONCLUSIONS

It is of crucial importance to perform full cardiac imaging that includes CMR even in asymptomatic patients with suspected EGPA, since early identification of cardiac involvement may allow to apply appropriate therapy and full recovery of the patient.