Mesenteric lymph nodes seen at imaging: causes and significance

Calcified axillary lymph nodes in a case of de novo metastatic breast cancer

At the time of a mammogram, calcifications may be seen in axillary lymph nodes. Metastatic breast cancer is the most common malignant cause of calcifications in the axillary lymph nodes. Benign causes may include but are not limited to granulomatous disease, fat necrosis, gold deposits in rheumatoid arthritis patients, pigmentation from tattoos, and sarcoidosis. We present a case of a 37-year-old female with axillary lymph node calcifications due to metastatic breast cancer. Calcification morphology seen in the primary breast tumor and the axillary lymph nodes are nearly identical on mammogram, which is seldom seen. The similar morphology almost guarantees metastatic breast cancer, underscoring the importance of identifying the etiology of any calcifications present in axillary lymph nodes on mammography.

Is 10 cm ileal resection sufficient in locally advanced caecal cancer surgery?

BACKGROUND

There is no consensus as to how much ileal resection is sufficient when performing a right hemicolectomy for right colon cancers. Locally advanced caecal cancer has the highest incidence of peri-ileal lymph node metastasis. Therefore, this study investigated whether the 10 cm ileum resection suggested by the Japanese Society for Cancer of the Colon and Rectum is oncologically safe in stage II and III caecal cancer.

METHODS

The prospectively collected medical records of stage II and III caecal cancer patients who underwent a right hemicolectomy with at least D2 lymph node dissection were reviewed retrospectively. The patients were divided into two groups according to the length of proximal ileal resected: group 1 (≤10 cm) and group 2 (>10 cm). Factors contributing to the 5-year overall survival (OS) were analysed.

RESULTS

The study enrolled 89 patients with pathological stage II or III caecal cancer. The >10 cm group tended to be younger (P = 0.0938) with higher pathological N stages (P = 0.0899) than the ≤10 cm group. The 5-year OS did not differ between the two groups. No significant difference was found between the two groups according to stage. Age (HR = 1.06, 95% CI = 1.02-1.10, P = 0.0069) and N2 stage (HR = 5.38, 95% CI = 1.90-15.28, P = 0.0016) were significantly associated with OS in both uni- and multivariate analyses.

CONCLUSIONS

There was no OS benefit to resecting >10 cm of ileum in either stage II or III caecal cancer patients. Hence, we suggest that the '10 cm rule' is sufficient for stage II and III caecal cancer patients.

Update on acute appendicitis: Typical and untypical findings

Acute appendicitis is the most common indication for emergency abdominal surgery throughout the world and a common reason for consultation in emergency departments. In recent decades, diagnostic imaging has played a fundamental role in identifying acute appendicitis, helping to reduce the rate of blind laparotomies and hospital costs. Given the results of clinical trials supporting the use of antibiotic therapy over surgical treatment, radiologists need to know the diagnostic criteria for complicated acute appendicitis to be able to recommend the best treatment option. This review aims not only to define the diagnostic criteria for appendicitis in different imaging modalities (ultrasonography, computed tomography, and magnetic resonance imaging), but also to explain the diagnostic protocols, atypical presentations, and other conditions that can mimic appendicitis.

Abdominal Lymphadenopathies: Lymphoma, Brucellosis or Tuberculosis? Multidisciplinary Approach-Case Report and Review of the Literature

Abdominal pain represents a frequent symptom for referral to emergency departments and/or internal medicine outpatient setting. Similarly, fever, fatigue and weight loss are non-specific manifestations of disease. The present case describes the diagnostic process in a patient with abdominal pain and a palpable abdominal mass. Abdominal ultrasonography confirmed the presence of a mass in the mesogastrium. Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) scans oriented toward calcific lymphadenopathies with increased metabolism in the positron emission tomography-computed tomography (PET-CT) scan. Laboratory examinations were inconclusive, although serology for Brucella and the Quantiferon test were positive. After multidisciplinary discussion, the patient underwent surgical excision of the abdominal mass. Histological examination excluded malignancies and oriented toward brucellosis in a patient with latent tuberculosis. The patient was treated with rifampin 600 mg qd and doxycycline 100 mg bid for 6 weeks with resolution of the symptoms. In addition, rifampin was continued for a total of 6 months in order to treat latent tuberculosis. This case underlines the need for a multidisciplinary approach in the diagnostic approach to abdominal lymphadenopathies.

The diagnosis and management of suspected lymphoma in general practice

With rapid advancements in diagnosis and treatment of malignancies, the gap between generalists and subspecialists continues to widen, particularly in cancers like lymphoma where the spectrum of disease varies from indolent to rapidly progressive. Prior to establishing with a hematologist/oncologist, patients must be accurately and comprehensively diagnosed and managed for lymphoma in the generalist setting. In the following manuscript, we review the common clinical presentations in which should raise concern for lymphoma. We summarize the literature regarding the role of laboratory studies including complete blood count and peripheral blood flow cytometry, the recommendations for lymph node sampling, the role and selection of imaging modalities, and ideal patient monitoring for high-risk clinical syndromes that may be encountered in lymphoma.

Development of scalable lymphatic system in the 4D XCAT phantom: Application to quantitative evaluation of lymphoma PET segmentations

BACKGROUND

Digital anthropomorphic phantoms, such as the 4D extended cardiac-torso (XCAT) phantom, are actively used to develop, optimize, and evaluate a variety of imaging applications, allowing for realistic patient modeling and knowledge of ground truth. The XCAT phantom defines the activity and attenuation for a simulated patient, which includes a complete set of organs, muscle, bone, and soft tissue, while also accounting for cardiac and respiratory motion. However, the XCAT phantom does not currently include the lymphatic system, critical for evaluating medical imaging tasks such as sentinel node detection, node density measurement, and radiation dosimetry.

PURPOSE

In this study, we aimed to develop a scalable lymphatic system in the XCAT phantom, to facilitate improved research of the lymphatic system in medical imaging. Using this scalable lymphatic system, we modeled the lymph node conglomerate pathology that is characteristically observed in primary mediastinal B-cell lymphoma (PMBCL). As an extended application, we evaluated positron emission tomography (PET) image quantification of metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of these simulated lymphomas, though the phantoms may be applied to other imaging modalities and study design paradigms (e.g., image quality, detection).

METHODS

A template model for the lymphatic system was developed based on anatomical data from the Visible Human Project of the National Library of Medicine. The segmented nodes and vessels were fit with non-uniform rational basis spline surfaces, and multichannel large deformation diffeomorphic metric mapping was used to propagate the template to different XCAT anatomies. To model conglomerates observed in PMBCL, lymph nodes were enlarged, converged within the mediastinum, and tracer concentration was increased. We used the phantoms as inputs to a PET simulation tool, which generated images using ordered subsets expectation maximization reconstruction with 2-8 mm Gaussian filters. Fixed thresholding (FT) and gradient segmentation were used to determine MTV and TLG. Percent bias (%Bias) and coefficient of variation (COV) were computed as measures of accuracy and precision, respectively, for each MTV and TLG measurement.

RESULTS

Using the methodology described above, we introduced a scalable lymphatic system in the XCAT phantom, which allows for the radioactivity and attenuation ground truth to be generated in 116 ± 2.5 s using a 2.3 GHz processor. Within the Rhinoceros interface, lymph node anatomy and function were modified to create a cohort of 10 phantoms with lymph node conglomerates. Using the lymphoma phantoms to evaluate PET quantification of MTV, mean %Bias values were -9.3%, -41.3%, and 20.9%, while COV values were 4.08%, 7.6%, and 3.4% using 25% FT, 40% FT, and gradient segmentations, respectively. Comparatively for TLG, mean %Bias values were -27.4%, -45.8%, and -16.0%, while COV values were 1.9%, 5.7%, and 1.4%, for the 25% FT, 40% FT, and gradient segmentations, respectively.

CONCLUSIONS

In this work, we upgraded the XCAT phantom to include a lymphatic system, comprised of a network of 276 scalable lymph nodes and corresponding vessels. As an application, we created a cohort of phantoms with lymph node conglomerates to evaluate lymphoma quantification in PET imaging, which highlights an important application of this work.

Insights on the Gut-Mesentery-Lung Axis in Pulmonary Arterial Hypertension: A Poorly Investigated Crossroad

Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by the hyperproliferation of vascular cells, including smooth muscle and endothelial cells. Hyperproliferative cells eventually obstruct the lung vasculature, leading to irreversible lesions that collectively drive pulmonary pressure to life-threatening levels. Although the primary cause of PAH is not fully understood, several studies have indicated it results from chronic pulmonary inflammation, such as observed in response to pathogens' infection. Curiously, infection by the intravascular parasite Schistosoma mansoni recapitulates several aspects of the widespread pulmonary inflammation that leads to development of chronic PAH. Globally, >200 million people are currently infected by Schistosoma spp., with about 5% developing PAH (Sch-PAH) in response to the parasite egg-induced obliteration and remodeling of the lung vasculature. Before their settling into the lungs, Schistosoma eggs are released inside the mesenteric veins, where they either cross the intestinal wall and disturb the gut microbiome or migrate to other organs, including the lungs and liver, increasing pressure. Spontaneous or surgical liver bypass via collateral circulation alleviates the pressure in the portal system; however, it also allows the translocation of pathogens, toxins, and antigens into the lungs, ultimately causing PAH. This brief review provides an overview of the gut-mesentery-lung axis during PAH, with a particular focus on Sch-PAH, and attempts to delineate the mechanism by which pathogen translocation might contribute to the onset of chronic pulmonary vascular diseases.

Does contrast-enhanced computed tomography raise awareness in the diagnosis of the invisible side of celiac disease in adults?

PURPOSE

This study aimed to evaluate the diagnosis and determine major and minor criteria of celiac disease (CD) with the malabsorption patterns (MABP) in the small intestine and colon on computed tomography (CT) and additional CT findings.

METHODS

This retrospective study was conducted with 116 patients diagnosed with CD, 14 CD patients recovering with treatment, and 35 control patients with non-CD. All patients had CT examinations and histopathological diagnoses. The sensitivity, specificity, PPV, NPV, and accuracy values of each CT finding defined in the literature were statistically evaluated. According to the patient and control groups, the numerical values of the findings and the sensitivity and specificity values were measured according to this cut-off value. The distribution of CT findings according to pathological Marsh data was evaluated in CD patients.

RESULTS

Sensitivity and specificity were found to be higher in small bowel MABP findings, mesenteric hypervascularity, and increased SMV/aorta diameter. There was a numerically significant difference in MDCT findings between the control and pathological Marsh groups. In the ROC analysis performed in terms of the total numerical values of each MDCT finding observed between the groups, it was found that there were more than 7 MDCT findings, 100% sensitivity, and 92% specificity. The presence of four major and three minor criteria or three major and four minor criteria were considered significant.

CONCLUSIONS

Being aware of CT findings below the iceberg that may suggest CD in abdominal CT examinations performed in patients with atypical clinical and malabsorption findings or other nonspecific findings may prevent diagnostic delay and unnecessary procedures.

Ovarian cancer reporting lexicon for computed tomography (CT) and magnetic resonance (MR) imaging developed by the SAR Uterine and Ovarian Cancer Disease-Focused Panel and the ESUR Female Pelvic Imaging Working Group

OBJECTIVES

Imaging evaluation is an essential part of treatment planning for patients with ovarian cancer. Variation in the terminology used for describing ovarian cancer on computed tomography (CT) and magnetic resonance (MR) imaging can lead to ambiguity and inconsistency in clinical radiology reports. The aim of this collaborative project between Society of Abdominal Radiology (SAR) Uterine and Ovarian Cancer (UOC) Disease-focused Panel (DFP) and the European Society of Uroradiology (ESUR) Female Pelvic Imaging (FPI) Working Group was to develop an ovarian cancer reporting lexicon for CT and MR imaging.

METHODS

Twenty-one members of the SAR UOC DFP and ESUR FPI working group, one radiology clinical fellow, and two gynecologic oncology surgeons formed the Ovarian Cancer Reporting Lexicon Committee. Two attending radiologist members of the committee prepared a preliminary list of imaging terms that was sent as an online survey to 173 radiologists and gynecologic oncologic physicians, of whom 67 responded to the survey. The committee reviewed these responses to create a final consensus list of lexicon terms.

RESULTS

An ovarian cancer reporting lexicon was created for CT and MR Imaging. This consensus-based lexicon has 6 major categories of terms: general, adnexal lesion-specific, peritoneal carcinomatosis-specific, lymph node-specific, metastatic disease -specific, and fluid-specific.

CONCLUSIONS

This lexicon for CT and MR imaging evaluation of ovarian cancer patients has the capacity to improve the clarity and consistency of reporting disease sites seen on imaging.

KEY POINTS

• This reporting lexicon for CT and MR imaging provides a list of consensus-based, standardized terms and definitions for reporting sites of ovarian cancer on imaging at initial diagnosis or follow-up. • Use of standardized terms and morphologic imaging descriptors can help improve interdisciplinary communication of disease extent and facilitate optimal patient management. • The radiologists should identify and communicate areas of disease, including difficult to resect or potentially unresectable disease that may limit the ability to achieve optimal resection.

Clinicopathologic Features of Gynecologic Malignancies Presenting Clinically as Colonic Malignancies

OBJECTIVES

To systematically evaluate gynecologic malignancies (adnexal or uterine) causing gastrointestinal (GI) signs (eg, mass on colonoscopy) or symptoms (eg, bloody stools) clinically mimicking a GI primary malignancy.

METHODS

The archives of 2 institutions were retrospectively reviewed for gynecologic malignancies clinically manifesting as colonic lesions. For each case, available radiologic, endoscopic, and histologic findings were recorded.

RESULTS

We identified 16 cases: 13 biopsies and 3 resections. The masses were localized in the rectosigmoid (14 cases [88%]), right (1 case [6%]), and transverse (1 case [6%]) colon. Gastrointestinal-type complaints included abdominal pain, weight loss, hematochezia, and obstruction; 1 case was asymptomatic and found during screening colonoscopy. Nine patients (56%) had no known prior gynecologic malignancy, and in only 2 of these patients was there some clinical suspicion of a noncolonic primary malignancy. Most cases (13 [81%]) were serous carcinoma, usually high-grade adnexal or primary peritoneal. Six cases (38%) directly extended into the colon, and 7 (44%) metastasized; route of spread was unclear in the others. Only 1 case (6%) showed mucosal involvement, and none showed desmoplasia or dirty necrosis. Four of the 13 serous carcinomas (31%) showed psammoma bodies.

CONCLUSIONS

Advanced gynecologic malignancies, most commonly serous carcinoma, can rarely manifest as GI lesions. Clues to noncolonic origin on biopsy include lack of colonic mucosal involvement/dysplasia, desmoplasia, or dirty necrosis.

Appendiceal involvement in pediatric inflammatory multisystem syndrome temporally associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2): a diagnostic challenge in the coronavirus disease (COVID) era

BACKGROUND

Many studies on pediatric inflammatory multisystem syndrome temporally associated with severe acute respiratory syndrome coronavirus 2 (PIMS-TS) have described abdominal findings as part of multisystem involvement, with limited descriptions of abdominal imaging findings specific to PIMS-TS.

OBJECTIVE

To perform a detailed evaluation of abdominal imaging findings in children with PIMS-TS.

MATERIALS AND METHODS

We performed a single-center retrospective study of children admitted to our institution between April 2020 and January 2021 who fulfilled Royal College of Paediatrics and Child Health criteria for PIMS-TS and who had cross-sectional abdominal imaging. We studied clinical data, abdominal imaging, laboratory markers, echocardiography findings, treatment and outcomes for these children. We also reviewed the literature on similar studies.

RESULTS

During the study period, 60 PIMS-TS cases were admitted, of whom 23 required abdominal imaging. Most (74%) were from a Black, Asian or minority ethnic background and they had an average age of 7 years (range 2-14 years). All children had fever and gastrointestinal symptoms on presentation with elevated C-reactive protein, D-dimer and fibrinogen. Most had lymphopenia, raised ferritin and hypoalbuminemia, with positive severe acute respiratory syndrome coronavirus 2 immunoglobulin G antibodies in 65%. Free fluid (78%), right iliac fossa mesenteric inflammation (52%), and significantly enlarged mesenteric lymph nodes (52%) were the most common imaging findings. Appendiceal inflammation (30%) and abnormal distal ileum and cecum/ascending colon wall thickening (35%) were also common. All children responded well to medical management alone, with no mortality.

CONCLUSION

In addition to free fluid, prominent lymphadenopathy, and inflammatory changes in the right iliac fossa, we found abnormal long-segment ileal thickening and appendicitis to be frequent findings. Recognition of appendiceal involvement as a component of the PIMS-TS spectrum should help clinicians avoid unnecessary surgical intervention as part of a multidisciplinary team approach.

Smart design approaches for orally administered lipophilic prodrugs to promote lymphatic transport

Challenges to effective delivery of drugs following oral administration has attracted growing interest over recent decades. Small molecule drugs (<1000 Da) are generally absorbed across the gastrointestinal tract into the portal blood and further transported to the systemic circulation via the liver. This can result in a significant reduction to the oral bioavailability of drugs that are metabolically labile and ultimately lead to ineffective exposure and treatment. Targeting drug delivery to the intestinal lymphatics is attracting increased attention as an alternative route of drug transportation providing multiple benefits. These include bypassing hepatic first-pass metabolism and selectively targeting disease reservoirs residing within the lymphatic system. The particular physicochemical requirements for drugs to be able to access the lymphatics after oral delivery include high lipophilicity (logP>5) and high long-chain triglyceride solubility (> 50 mg/g), properties required to enable drug association with the lipoprotein transport pathway. The majority of small molecule drugs, however, are not this lipophilic and therefore not substantially transported via the intestinal lymph. This has contributed to a growing body of investigation into prodrug approaches to deliver drugs to the lymphatic system by chemical manipulation. Optimised lipophilic prodrugs have the potential to increase lymphatic transport thereby improving oral pharmacokinetics via a reduction in first pass metabolism and may also target of disease-specific reservoirs within the lymphatics. This may provide advantages for current pharmacotherapy approaches for a wide array of pathological conditions, e.g. immune disease, cancer and metabolic disease, and also presents a promising approach for advanced vaccination strategies. In this review, specific emphasis is placed on medicinal chemistry strategies that have been successfully employed to design lipophilic prodrugs to deliberately enable lymphatic transport. Recent progress and opportunities in medicinal chemistry and drug delivery that enable new platforms for efficacious and safe delivery of drugs are critically evaluated.

Mastocytosis-A Review of Disease Spectrum with Imaging Correlation

Simple Summary

In this review will discuss the clinical presentation, pathophysiology, and role of imaging in detection and extent estimation of the systemic involvement of the disease, in addition to demonstration of appearance on varying imaging modalities. Familiarity with the potential imaging findings associated with mastocytosis can aid in early disease diagnosis and classification and accordingly can lead directing further work up and better management.

Abstract

Mastocytosis is a rare disorder due to the abnormal proliferation of clonal mast cells. Mast cells exist in most tissues, mature in situ from hematopoietic stem cells and develop unique characteristics of local effector cells. Mastocytosis develops by activation mutation of the KIT surface receptor which is involved in the proliferation of a number of cell lines such as mast cells, germ cells, melanocytes, and hematopoietic cells. It manifests as two main categories: cutaneous mastocytosis and systemic mastocytosis. Imaging can play an important role in detection and characterization of the disease manifestation, not only by radiography and bone scans, but also magnetic resonance imaging and computed tomography, which can be more sensitive in the assessment of distinctive disease patterns. Radiologists should be aware of various appearances of this disease to better facilitate diagnosis and patient management. Accordingly, this review will discuss the clinical presentation, pathophysiology, and role of imaging in detection and extent estimation of the systemic involvement of the disease, in addition to demonstration of appearance on varying imaging modalities. Familiarity with the potential imaging findings associated with mastocytosis can aid in early disease diagnosis and classification and accordingly can lead directing further work up and better management.

Could CT abdomen and PET/CT be helpful in early diagnosis of Whipple's disease? A case report

Whipple’s disease is a rare disease, which can be fatal if not treated. It is often diagnosed at a late stage because of the varied disease presentation and its rare incidence. Classic Whipple’s disease presents with arthralgia, abdominal pain, diarrhea and weight loss. CT abdomen may show mesenteric lymphadenopathy with hypodense centers. These CT findings along with clinical presentation should prompt early diagnosis of Whipple’s disease. We present a case of classic Whipple’s disease with interesting CT abdomen and PET scan findings.

Computed-tomography based scoring system predicts outcome for clinical lymph node-positive patients undergoing radical cystectomy

Purpose:

Contrast-enhanced CT scan is the standard staging modality for patients with bladder cancer undergoing radical cystectomy (RC). Involvement of lymph nodes (LN) determines prognosis of patients with bladder cancer. The detection of LN metastasis by CT scan is still insufficient. Therefore, we investigated various CT scan characteristics to predict lymph node ratio (LNR) and its impact on survival. Also, pre-operative CT scan characteristics might hold potential to risk stratify cN+ patients.

Materials and Methods:

We analyzed preoperative CT scans of patients undergoing RC in a tertiary high volume center. Retrospectively, local tumor stage and LN characteristics such as size, morphology (MLN) and number of loco-regional LN (NLN) were investigated and correlation to LNR and survival was analyzed. CT scan characteristics were used to develop a risk stratification using Kaplan-Maier and multivariate analysis.

Results:

764 cN0 and 166 cN+ patients with complete follow-up and imaging data were included in the study. Accuracy to detect LN metastasis and locally advanced tumor stage in CT scan was 72% and 62%. LN larger than 15mm in diameter were significantly associated with higher LNR (p=0.002). Increased NLN correlated with decreased CSS and OS (p=0.001: p=0.002). Furthermore, CT scan based scoring system precisely differentiates low-risk and high-risk profiles to predict oncological outcome (p <0.001).

Conclusion:

In our study, solely LN size >15mm significantly correlated with higher LNR. Identification of increased loco-regional LN was associated with worse survival. For the first time, precise risk stratification based on computed-tomography findings was developed to predict oncological outcome for clinical lymph node-positive patients undergoing RC.

Assessing Lymphatic Uptake of Lipids Using Magnetic Resonance Imaging: A Feasibility Study in Healthy Human Volunteers with Potential Application for Tracking Lymph Node Delivery of Drugs and Formulation Excipients

Dietary lipids and some pharmaceutical lipid excipients can facilitate the targeted delivery of drugs to the intestinal lymphatics. Here, the feasibility of magnetic resonance imaging (MRI) for imaging lipid uptake into the intestinal lymphatics was assessed, shedding light on which lymph nodes can be targeted using this approach. Three healthy male volunteers were scanned at 3.0 T at baseline, 120, 180, 240, and 300 min post high-fat meal. A sagittal multi-slice image was acquired using a diffusion-weighted whole-body imaging sequence with background suppression (DWIBS) (pre inversion TI = 260 ms). Changes in area, major, and minor axis length were compared at each time point. Apparent diffusion coefficient (ADC) was calculated (b = 0 and 600 s/mm²) across eight slices. An average of 22 nodes could be visualised across all time points. ADC increased at 120 and 180 min compared to the baseline in all three participants by an average of 9.2% and 6.8%, respectively. In two participants, mean node area and major axis lengths increased at 120 and 180 min relative to the baseline. In conclusion, the method described shows potential for repeated lymph node measurements and the tracking of lipid uptake into the lymphatics. Further studies should focus on methodology optimisation in a larger cohort.

Combining quantitative and qualitative magnetic resonance imaging features to differentiate anorectal malignant melanoma from low rectal cancer

BACKGROUND

Distinguishing anorectal malignant melanoma from low rectal cancer remains challenging because of the overlap of clinical symptoms and imaging findings. We aim to investigate whether combining quantitative and qualitative magnetic resonance imaging (MRI) features could differentiate anorectal malignant melanoma from low rectal cancer.

METHODS

Thirty-seven anorectal malignant melanoma and 98 low rectal cancer patients who underwent pre-operative rectal MRI from three hospitals were retrospectively enrolled. All patients were divided into the primary cohort (N = 84) and validation cohort (N = 51). Quantitative image analysis was performed on T1-weighted (T1WI), T2-weighted (T2WI), and contrast-enhanced T1-weighted imaging (CE-T1WI). The subjective qualitative MRI findings were evaluated by two radiologists in consensus. Multivariable analysis was performed using stepwise logistic regression. The discrimination performance was assessed by the area under the receiver operating characteristic curve (AUC) with a 95% confidence interval (CI).

RESULTS

The skewness derived from T2WI (T2WI-skewness) showed the best discrimination performance among the entire quantitative image features for differentiating anorectal malignant melanoma from low rectal cancer (primary cohort: AUC = 0.852, 95% CI 0.788-0.916; validation cohort: 0.730, 0.645-0.815). Multivariable analysis indicated that T2WI-skewness and the signal intensity of T1WI were independent factors, and incorporating both factors achieved good discrimination performance in two cohorts (primary cohort: AUC = 0.913, 95% CI 0.868-0.958; validation cohort: 0.902, 0.844-0.960).

CONCLUSIONS

Incorporating T2WI-skewness and the signal intensity of T1WI achieved good performance for differentiating anorectal malignant melanoma from low rectal cancer. The quantitative image analysis helps improve diagnostic accuracy.

Immunoglobulin G4-related systemic disease: mesenteric and peritoneal involvement with radiopathological correlation and differential diagnoses

Since its first introduction in 2003 by Kamisawa et al., IgG4-related disease has gained wide interest in the imaging community, and several manuscripts have been published regarding its imaging features. In addition to initial observations in the pancreaticobiliary system, it is now well known that the disease may involve every organ system in the body. There is not much information in the imaging literature about the involvement of mesentery, omentum, and peritoneum in this disease. This article aims to provide more information about the imaging findings of IgG4-related disease regarding these areas by making radiopathological correlations and discussing the possible differential diagnoses.

HIV Lymphadenopathy: Differential Diagnosis and Important Imaging Features

OBJECTIVE. The purpose of this article is to review important imaging and clinical features to help elucidate causes of lymphadenopathy in patients with HIV infection. CONCLUSION. HIV lymphadenopathy has various causes generally categorized as inflammatory or reactive, such as immune reconstitution syndrome; infectious, such as tuberculous and nontuberculous mycobacterial infections and HIV infection itself; and neoplastic, such as lymphoma, Kaposi sarcoma, and Castleman disease. It is important to consider patients' demographic characteristics, clinical presentations, CD4 lymphocyte counts, and radiologic features to identify likely causes of lymphadenopathy.

A rare case of abdominal tuberculosis

Abdominal tuberculosis (TB) is a rare condition in developed nations and can be challenging to diagnose. This report concerns a 45-year-old patient who presented with abdominal pain and fever and would undergo a lengthy hospital admission complicated by a previously undiagnosed HIV infection. Computed tomography imaging performed the day our patient presented to the emergency room revealed rather classic findings corresponding with abdominal tuberculosis However, diagnostic difficulty delayed the diagnosis and treatment. This case highlights radiologists' opportunity to raise clinical suspicion early in hospital care, especially in a rare disease process that can have poor outcomes.

Unravelling the Mysteries of the Mesentery

The mesentery and its folds tether the small bowel loops to the posterior abdominal wall. It transmits nerves, vessels, and lymph ensconced in a fatty sponge layer wrapped in a thin glistening peritoneum, from and to the small bowel. Not only does this flexible dynamic fatty apron house various localized primary benign and malignant lesions, it is often involved in and gives an indication of generalized or systemic diseases in the body. An understanding of the anatomy, components, and function of the mesentery helps to classify mesenteric abnormalities. This further allows for characterizing radiological patterns and appearances specific to certain disease entities. Recent reviews of mesenteric anatomy have kindled new interest in its function and clinical applications, heralding the possibility of revision of its role in diseases of the abdomen.

Imaging of appendicitis: Tips and tricks

Acute appendicitis is one of the most common surgical emergencies worldwide. Over the past 30 years, imaging has become central to the diagnosis of appendicitis, reducing both negative appendicectomy rate and healthcare expenses. Appendicitis can be challenging in many ways for radiologists with various clinical presentations, complications and differential diagnoses. The aim of this review is to present a step-by-step reasoning with key findings, tips and tricks leading to the diagnosis of appendicitis and its complications. The first steps are with the use of the appropriate imaging modality (US, CT and MRI) to locate the appendix in abdominal cavity and to identify the features of appendicitis and its complications through specific imaging signs. The next steps are to eliminate an unusual morphology of the appendix that may simulate acute appendicitis and to recognize an unusual imaging presentation of appendicitis. Then, to corroborate the diagnosis of appendicitis, the last step is to rule out any differential diagnoses mainly from the genitourinary and gastrointestinal tracts. Following these steps can help to accurately diagnose appendicitis and its complications.

Visual PET/CT scoring of mesenteric fdg uptake to differentiate between tuberculous peritonitis and peritoneal carcinomatosis

PURPOSE

We aimed to differentiate tuberculous peritonitis (TBP) from peritoneal carcinomatosis (PC) using a visual positron-emission tomography/computed tomography (PET/CT) scoring system based on mesenteric fluorodeoxyglucose (FDG) uptake.

METHODS

PET/CT scans from 31 patients with TBP and 92 patients with PC were retrospectively reviewed. A visual PET/CT scoring system for mesenteric FDG uptake was used according to the following characteristics: FDG uptake intensity (low = 0, moderate = 1, high = 2), FDG uptake deposits (uniform = 0, irregular = 1, ascitic = 2), FDG uptake focality (diffuse = 0, segmental = 1, focal = 2), nodularity on the corresponding CT (nonnodular = 0, micronodular = 1, macronodular = 2) and mesenteric lymphadenopathy (absent = 0, lymphadenopathy without FDG uptake = 1, lymphadenopathy with FDG uptake = 2). The FDG uptake intensity, deposits, focality, nodularity and mesenteric lymphadenopathy scores between TBP and PC were compared using chi-square tests. The diagnostic performance of this scoring system for differentiating TBP from PC was analyzed using a receiver operating characteristic (ROC) curve. P < 0.05 was considered statistically significant.

RESULTS

Twenty-four patients with TBP (77.4%) and 56 patients with PC (60.9%) had mesenteric FDG uptake (P = 0.095) and were included for evaluation with the visual PET/CT scoring system. PC lesions scored higher than TBP lesions in FDG uptake deposits (P < 0.001), focality (P < 0.001) and nodularity (P < 0.001). No significant differences were observed between PC and TBP lesions in FDG uptake intensity (P = 0.396) and lymphadenopathy (P = 0.074). The total score that combined deposits, focality and nodularity had significant value for differentiating TBP from PC (area under the curve (AUC) = 0.869, P < 0.001), and a cutoff > 1 had a sensitivity (the accuracy for diagnosis of PC) of 80.4% and a specificity (the accuracy for diagnosis of TBP) of 75.0%.

CONCLUSION

A visual PET/CT scoring system based on mesenteric FDG uptake performed well in differentiating between TBP and PC.

Clinical significance of regional lymph node enlargement in patients with EGC within the expanded criteria for ESD

BACKGROUND

Lymph node (LN) metastasis is negligible in early gastric cancer (EGC) within expanded criteria for endoscopic submucosal dissection (ESD). However, regional lymph nodes in abdominal CT scans are sometimes enlarged in patients with EGC within the expanded criteria for endoscopic submucosal dissection (ESD). In this study, we investigated the clinical significance of regional lymph node enlargement on abdominal CT scan in patients with EGC within the expanded criteria for ESD.

METHODS

From December 2010 to April 2015, among 301 patients with EGC within the ESD expanded criteria, 47 patients with regional lymph node enlargement shown by abdominal CT scan were prospectively enrolled. We performed surgical resection or periodic follow-up with abdominal CT scans and upper endoscopy every 6 months to evaluate whether the enlarged lymph nodes are due to metastasis or a reactive change.

RESULTS

The mean age of the 47 patients (38 males, 9 female) was 64.8 years. The enlarged lymph nodes were usually single (26/47, 44.6%) and sized as follows: 11 nodes were ≤ 5 mm, 19 were 6-10 mm, and 17 were ≥ 10 mm. Four of the 47 patients initially underwent surgical resection, and 8 patients underwent surgical resection after ESD. However, there was no lymph node metastasis in surgical specimens. Thirty-five patients received ESD and periodically followed up at a median duration of 56 months (IQR: 44-59 month). The enlarged lymph node disappeared in 12 of 35 patients, decreased in 9 patients and remained the same size in 13 patients, and increased in 1 patient.

CONCLUSION

Regional lymph node enlargement on abdominal CT scan in patients within expanded criteria for ESD of ECG may be not due to metastasis but a reactive change.

Imaging in discriminating intestinal tuberculosis and Crohn's disease: past, present and the future

Introduction: Intestinal tuberculosis (ITB) and Crohn's disease (CD) have similar clinical presentation, but require different treatment approaches. Despite advances in various endoscopic, imaging, microbiological, and histological techniques, the differentiation of these two entities is often difficult. Newer radiological and image acquisition modalities have now become indispensable tools for evaluation of these two diseases.Areas covered: This review summarizes the currently available literature on various radiological investigations to differentiate ITB from CD. This review also enumerates the newer modalities in image acquisition techniques and their potential role for differentiating these two diseases. At present abdominal computed tomography (CT) scan is used as a first line investigation for differentiating ITB from CD. Magnetic resonance imaging (MRI) is preferred in pediatric patients and for follow-up studies.Expert opinion: Role of newer modalities like contrast enhanced abdominal ultrasound, perfusion CT, advanced MRI and positron emission tomography (PET) is evolving and requires further exploration. Till further robust studies are available, differentiation between ITB and CD requires use of a combination of clinical, endoscopic, serological, histological, and radiological parameters rather than relying on a single test.

[Imaging of gastrointestinal inflammation : Characteristic patterns and signs]

CLINICAL PROBLEM

Pathological conditions of the gastrointestinal tract can result from various disorders, including inflammatory, infectious, neoplastic, and ischemic diseases.

RADIOLOGICAL STANDARD PROCEDURES

Cross-sectional imaging techniques have largely replaced many of the conventional fluoroscopic examinations, such as small bowel follow-through and double-contrast barium enema. The former allow for time-efficient, accurate, and minimally invasive diagnostics. Therefore, they have become important diagnostic tools for the evaluation of inflammatory diseases of the gastrointestinal tract. The distension of the intestinal lumen with orally administered neutral contrast media improves not only the evaluation of the intraluminal aspect, but also of the cross-sectional appearance. Furthermore, with cross-sectional imaging techniques, the additional assessment of the extraintestinal structures and organs is also possible.

METHODICAL INNOVATIONS AND ASSESSMENT

With the ongoing development of scanner and software technology, pathologic conditions of the gastrointestinal wall can be characterized in more detail by both computed tomography and magnetic resonance imaging. A structured approach, based on the analysis of typical radiological signs and patterns, combined with the evaluation of extraintestinal findings may help to assign the observed imaging findings to specific disease groups.

RECOMMENDATIONS

This article summarizes common signs and typical patterns frequently seen in inflammatory conditions of the gastrointestinal tract. A systematic approach for structured analysis of specific and nonspecific imaging features and common pitfalls may aid in the interpretation and help to narrow the spectrum of potential differential diagnoses.

Evaluation of Mesenteric Lymph Nodes in a Pediatric Population with Mesenteric Lymphadenitis Using Superb Microvascular Imaging

Background

This study aimed to evaluate superb microvascular imaging (SMI) as an adjunctive imaging method to evaluate mesenteric lymph nodes in children with mesenteric lymphadenitis compared with healthy children.

Material/Methods

A retrospective study compared children with mesenteric lymphadenitis (n=27) and healthy children (n=30). Lymph node size was determined using grayscale ultrasonography and parameters of lymph node vascularity were compared using color Doppler flow imaging (CDFI) and SMI. The diagnostic performance of ultrasound (US), US combined with SMI, and US combined with CDFI were compared.

Results

Lymph nodes from children with mesenteric lymphadenitis (n=77) and normal lymph nodes (n=84) were evaluated by SMI, which showed that the least diameter of lymph nodes in cases of mesenteric lymphadenitis was 0.58±0.15 mm and of normal mesenteric lymph nodes was 0.47±0.08 mm (p<0.001). SMI identified 92.6% of abnormal mesenteric lymph nodes while CDFI detected 85.2%. US combined with SMI had the highest sensitivity (81.5%), and specificity (78.9%) compared with US alone (sensitivity, 63.0%; specificity, 64.9%), and compared with US combined with CDFI (sensitivity, 74.1%; specificity, 75.4%). US combined with SMI and US combined with CDFI achieved the same specificity (76.7%), which was higher than that of US alone (66.7%).

Conclusions

SMI was superior to color Doppler flow imaging in evaluating the microvasculature in lymphadenopathy in mesenteric lymphadenitis. SMI may be used as an adjunct to grayscale ultrasonography to assist in identifying mesenteric lymphadenopathy in pediatric patients.

The hepatoduodenal ligament revisited: cross-sectional imaging spectrum of non-neoplastic conditions

INTRODUCTION

The hepatoduodenal ligament is frequently involved by conditions affecting the portal triad and surrounding structures, including a vast array of non-neoplastic conditions. Due its unique location between the retroperitoneum and the peritoneal space, the hepatoduodenal ligament is also targeted by inflammatory conditions involving the retroperitoneum and the liver. Finally, the presence of lymphatics and of the biliary tracts makes the hepatoduodenal ligament a route of spread for a variety of infections. The purpose of this pictorial essay is twofold: to review the cross-sectional radiological anatomy and variants of the structures within the hepatoduodenal ligament, and to illustrate the non-neoplastic conditions that may arise within the hepatoduodenal ligament.

CONCLUSION

Familiarity with these specific entities and their cross-sectional imaging findings is fundamental for a more accurate diagnosis.

Mesenteric Tuberculosis Masquerading as Carcinoid Tumor on Conventional Imaging and DOTANOC Positron Emission Tomography/Computed Tomography: Uncommon Presentation of a Common Disease

Carcinoid tumor of the mesentery has a classical imaging morphology. A specific diagnosis can often be provided on the basis of clinical history, elevated serum neuroendocrine markers, and uptake on somatostatin receptor-based radiotracer studies. Although a number of inflammatory and neoplastic conditions may mimic carcinoid tumor on many of these modalities, uptake on ⁶⁸Ga-DOTANOC positron emission tomography/computed tomography (PET/CT) is considered specific. We report a case of a 28-year-old male presenting with a mesenteric mass along with elevated serum neuroendocrine markers and uptake on DOTANOC PET/CT, all suggestive of carcinoid tumor. However, the histopathologic examination after surgical resection revealed necrotizing granulomas consistent with tuberculosis (TB). This case highlights the great masquerader that TB can be and stresses the importance of keeping a high index of suspicion for TB, especially in endemic areas.

HIV-related Malignancies and Mimics: Imaging Findings and Management

The risk of developing malignancy is higher in patients with human immunodeficiency virus (HIV) infection than in non-HIV-infected patients. Several factors including immunosuppression, viral coinfection, and high-risk lifestyle choices lead to higher rates of cancer in the HIV-infected population. A subset of HIV-related malignancies are considered to be acquired immunodeficiency syndrome (AIDS)-defining malignancies, as their presence confirms the diagnosis of AIDS in an HIV-infected patient. The introduction of highly active antiretroviral therapy (HAART) has led to a significant drop in the rate of AIDS-defining malignancies, including Kaposi sarcoma, non-Hodgkin lymphoma, and invasive cervical carcinoma. However, non-AIDS-defining malignancies (eg, Hodgkin lymphoma, lung cancer, hepatocellular carcinoma, and head and neck cancers) now account for an increasing number of cancer cases diagnosed in HIV-infected patients. Although the number has decreased, AIDS-defining malignancies account for 15%-19% of all deaths in HIV-infected patients in the post-HAART era. Most HIV-related malignancies in HIV-infected patients manifest at an earlier age with a more aggressive course than that of non-HIV-related malignancies. Understanding common HIV-related malignancies and their specific imaging features is crucial for making an accurate and early diagnosis, which impacts management. Owing to the weakened immune system of HIV-infected patients, other entities such as various infections, particularly opportunistic infections, are prevalent in these patients. These processes can have confounding clinical and imaging manifestations that mimic malignancy. This article reviews the most common AIDS-defining and non-AIDS-defining malignancies, the role of imaging in their diagnosis, and the imaging mimics of malignancies in HIV-infected patients. ^©RSNA, 2018.

Lipophilic activated ester prodrug approach for drug delivery to the intestinal lymphatic system

The intestinal lymphatic system plays an important role in the pathophysiology of multiple diseases including lymphomas, cancer metastasis, autoimmune diseases, and human immunodeficiency virus (HIV) infection. It is thus an important compartment for delivery of drugs in order to treat diseases associated with the lymphatic system. Lipophilic prodrug approaches have been used in the past to take advantage of the intestinal lymphatic transport processes to deliver drugs to the intestinal lymphatics. Most of the approaches previously adopted were based on very bulky prodrug moieties such as those mimicking triglycerides (TG). We now report a study in which a lipophilic prodrug approach was used to efficiently deliver bexarotene (BEX) and retinoic acid (RA) to the intestinal lymphatic system using activated ester prodrugs. A range of carboxylic ester prodrugs of BEX were designed and synthesised and all of the esters showed improved association with chylomicrons, which indicated an improved potential for delivery to the intestinal lymphatic system. The conversion rate of the prodrugs to BEX was the main determinant in delivery of BEX to the intestinal lymphatics, and activated ester prodrugs were prepared to enhance the conversion rate. As a result, an 4-(hydroxymethyl)-1,3-dioxol-2-one ester prodrug of BEX was able to increase the exposure of the mesenteric lymph nodes (MLNs) to BEX 17-fold compared to when BEX itself was administered. The activated ester prodrug approach was also applied to another drug, RA, where the exposure of the MLNs was increased 2.4-fold through the application of a similar cyclic activated prodrug. Synergism between BEX and RA was also demonstrated in vitro by cell growth inhibition assays using lymphoma cell lines. In conclusion, the activated ester prodrug approach results in efficient delivery of drugs to the intestinal lymphatic system, which could benefit patients affected by a large number of pathological conditions.

JOURNAL CLUB: Primary Anorectal Melanoma: MRI Findings and Clinicopathologic Correlations

OBJECTIVE

The purpose of this study is to evaluate the MRI features of primary anorectal malignant melanoma and to correlate these features with its clinical and pathologic characteristics.

MATERIALS AND METHODS

The medical records of 12 patients (five men and seven women; mean age [± SD], 60.8 ± 10.0 years) with pathologically proven primary anorectal melanoma were retrospectively reviewed. MRI findings were analyzed to determine the shape, size, distance from the anal verge, presence of perirectal or anal infiltration, signal intensity on T1- and T2-weighted images, presence of diffusion restriction, contrast enhancement pattern of the lesion, presence of lymphadenopathy, and occurrence of bowel obstruction. Subsequent follow-up data for the patients were recorded.

RESULTS

The most common presentation was hematochezia (41.7% of patients). Common findings on MRI included a large intraluminal polypoid mass (75.0% of lesions) with little perirectal or anal infiltration (100.0%), T1 hyperintensity (66.7%), high T2 signal intensity (54.5%) or mixed T2 signal intensity (45.5%), restricted diffusion (100.0%), and hyper-enhancement (100.0%). The mean length, width, and depth of these masses were 3.5, 2.9, and 2.3 cm, respectively. The mean distance from the anal verge was 1.8 cm. Lymphadenopathy was frequently identified (75.0% of cases), with lymph nodes larger than 2 cm noted in 28.5% of cases and most commonly involving the perirectal area (77.8% of cases). No colonic obstructions were observed. The mean patient follow-up was 32.7 months. A total of 25.0% of patients died as a result of disease progression.

CONCLUSION

The possibility of the presence of anorectal melanoma should be considered for patients with a bulky intraluminal polypoid mass in the anorectum without colonic obstruction, with the mass showing T1 hyperintensity, high or mixed signal T2 intensity, hyperenhancement, minimal perirectal or anal infiltration, and lymphadenopathy.

A Neglected Issue in Ulcerative Colitis: Mesenteric Lymph Nodes

Data evaluating the presence and characteristics of mesenteric lymph nodes (LNs) in patients with ulcerative colitis (UC) are scarce. The aim of this study is to determine the presence and characteristics of LNs in UC. The LN characteristics in computed tomography (CT), including LN dimension and attenuation, were evaluated retrospectively in 100 patients with UC (61 active and 39 inactive cases). Clinical characteristics and laboratory parameters, including CBC, biochemical analysis, erythrocyte sedimentation rate (ESR), and C reactive protein (CRP) were also compared. Mesenteric LNs were evident in all patients with UC. The attenuation and dimension of mesenteric LNs did not differ between active and inactive patients with UC. No correlation was found among patients with UC in terms of LN dimension, attenuation, ESR, CRP, leucocyte, and albumin (all with p > 0.05). The current study suggested that inflammation results in the development of mesenteric LN in UC, similar to Crohn’s disease and other inflammatory disorders.

Clinical Significance of Lymph Node Metastasis in the Mesentery of the Terminal Ileum in Patients With Right-sided Colon Tumors at Different Locations

BACKGROUND

There are limited reports on peri-ileal lymph node metastasis in patients with right-sided colon cancer, and little is known about their clinical significance.

OBJECTIVE

This study aimed to examine the role of tumor location in the prevalence and clinical significance of peri-ileal lymph node metastasis in patients with right-sided colon cancer.

DESIGN

This is a retrospective study from a prospective cohort database.

SETTINGS

The study was conducted at a tertiary referral hospital.

PATIENTS

Patients with right-sided colon cancer treated with radical surgery in a hospital between May 2006 and September 2016 were included.

MAIN OUTCOME MEASURES

The frequency of peri-ileal lymph node metastasis in the study cohort and the role of tumor location and the clinical characteristics of patients with peri-ileal lymph node metastasis were determined.

RESULTS

We examined 752 cases with right-sided colon cancer including 82 cecal, 554 ascending colon, and 116 hepatic flexure cancer. Twenty patients (2.7%) had peri-ileal lymph node metastasis. The incidence of metastasis to peri-ileal lymph nodes was 7.3% (6/82) in patients with cecal cancer, 2.2% (12/554) in patients with ascending colon cancer, and 1.7% (2/116) in patients with hepatic flexure cancer. Three patients had stage III cancer and 17 had stage IV. All 3 patients with positive peri-ileal lymph nodes and stage III cancer had cecal tumors. In contrast, all patients with ascending colon or hepatic flexure cancer and positive peri-ileal lymph nodes had stage IV cancer.

LIMITATIONS

The results were limited by the retrospective design of the study and the small number of patients with peri-ileal lymph node metastasis.

CONCLUSIONS

Peri-ileal lymph node metastasis was rare even in right-sided colon cancer and occurred mainly in stage IV. However, it occurred in some patients with locally advanced cecal cancer. These results suggest that optimal resection of the mesentery of the terminal ileum might have clinical benefit, especially in curative surgery for cecal cancer. See Video Abstract at http://links.lww.com/DCR/A556.

No Prophylactic Antibiotic Use for Young Children's Intussusception with Low-risk Infection after Successful Air Enema Reduction

The Chinese government has issued the policy of promulgating the clinical use of antibacterial drugs since 2011. Prophylactic antibiotic use is a challenging problem among young children with intussusception after successful air enema reduction. There were limited data regarding the clinical value of prophylactic antibiotics for intussusception with low-risk infections. A retrospective non-randomized comparative study was conducted among 188 young children with intussusception after successful air enema reduction between January 1, 2011 and December 30, 2013. Among these children, 51 received prophylactic antibiotics and 137 did not receive antibiotics. Our results showed that there were no significant differences in age, gender, weight, admission period, reduction interval, axillary temperature, leukocytes, neutrophils, lymphocytes, monocytes, mesenteric lymph nodes and complications between groups (P > 0.05). The national policy had significantly improved clinical use of antibiotic for young children with low-risk intussusception (OR < 0.001, P < 0.001). Inpatients days were longer for children used antibiotics than those who did not (median, 27.0 hours vs 21.0 hours, P = 0.003). Prophylactic antibiotics appeared to be of little value after the successful air enema reduction of intussusception in young children with low-risk infection. Policy intervention is effective for antibiotic use in China.

Acute small intestinal inflammation results in persistent lymphatic alterations

Inflammatory bowel disease (IBD) has a complex pathophysiology with limited treatments. Structural and functional changes in the intestinal lymphatic system have been associated with the disease, with increased risk of IBD occurrence linked to a history of acute intestinal injury. To examine the potential role of the lymphatic system in inflammation recurrence, we evaluated morphological and functional changes in mouse mucosal and mesenteric lymphatic vessels, and within the mesenteric lymph nodes during acute ileitis caused by a 7-day treatment with dextran sodium sulfate (DSS). We monitored whether the changes persisted during a 14-day recovery period and determined their potential consequences on dendritic cell (DC) trafficking between the mucosa and lymphoid tissues. DSS administration was associated with marked lymphatic abnormalities and dysfunctions exemplified by lymphangiectasia and lymphangiogenesis in the ileal mucosa and mesentery, increased mesenteric lymphatic vessel leakage, and lymphadenopathy. Lymphangiogenesis and lymphadenopathy were still evident after recovery from intestinal inflammation and correlated with higher numbers of DCs in mucosal and lymphatic tissues. Specifically, a deficit in CD103⁺ DCs observed during acute DSS in the lamina propria was reversed and further enhanced during recovery. We concluded that an acute intestinal insult caused alterations of the mesenteric lymphatic system, including lymphangiogenesis, which persisted after resolution of inflammation. These morphological and functional changes could compromise DC function and movement, increasing susceptibility to further gastrointestinal disease. Elucidation of the changes in mesenteric and intestinal lymphatic function should offer key insights for new therapeutic strategies in gastrointestinal disorders such as IBD. NEW & NOTEWORTHY Lymphatic integrity plays a critical role in small intestinal homeostasis. Acute intestinal insult in a mouse model of acute ileitis causes morphological and functional changes in mesenteric and intestinal lymphatic vessels. While some of the changes significantly regressed during inflammation resolution, others persisted, including lymphangiogenesis and altered dendritic cell function and movement, potentially increasing susceptibility to the recurrence of gastrointestinal inflammation.

Metastatic spread of solid subtype lung adenocarcinoma to the small intestine with anemia and melena: A case report

RATIONALE

Metastasis to the small intestine from a primary lung cancer is rare, and is associated with a poor prognosis. Early diagnosis of small intestine metastasis is difficult because of the low incidence of clinically apparent symptoms.

PATIENT CONCERNS

Clinical data and treatment of a 59-year-old man with small intestine metastasis from primary solid subtype lung adenocarcinoma are summarized.

DIAGNOSES

A man who was previously diagnosed with stage IIIA (T3N2M0) lung adenocarcinoma (solid subtype) came to our hospital for postoperative radiotherapy. Laboratory tests indicated anemia and melena. The patient was initially believed to have digestive ulcer and was treated with omeprazole, which proved to be ineffective. We conducted an abdominal computed tomography (CT) contrast scan and discovered a mass in the small intestine mass. Further positron emission tomography-computed tomography (PET-CT) imaging indicated the small intestine mass with fluorodeoxyglucose uptake.

INTERVENTIONS

The patient underwent an enterectomy and anastomosis. Pathological analysis confirmed the diagnosis of small intestinal metastasis from lung cancer with concomitant mesenteric lymph node metastasis.

OUTCOMES

One month after the operation, hemoglobin levels became normal, and the patient had good quality of life. However, 3 months after the operation, the patient suffered from anemia again. An abdominal CT scan indicated a new small intestine mass. Progression continued rapidly, and the patient died of hemorrhagic shock 5.5 months after the resection of the small intestine mass.

LESSONS

Although uncommon, if lung cancer patients present with anemia and melena, enteric metastasis should be part of the differential diagnosis. Abdominal CT scans and PET-CT are effective for early diagnosis. The prognosis of metastatic spread of solid subtype lung adenocarcinoma to the small intestine with mesenteric lymph node metastasis is poor. Subgroups of patients benefitting from metastasectomy and more effective systemic therapy need to be further investigated.

Mesenteric lymphadenitis as a presenting feature of Whipple's disease

Detecting Whipple’s disease, a “great imitator”, requires a high index of suspicion so that antimicrobial treatment can be initiated in a timely manner; a missed diagnosis can be fatal. Although an uncommon cause, Whipple’s disease must be considered in adults with mesenteric lymphadenitis. We report the case of a 39-year-old African American man who presented with chronic joint pain, chronic weight loss, and acute onset epigastric pain. Contrast-enhanced computed tomography of the abdomen and pelvis showed extensive mesenteric lymphadenopathy. A diagnosis of Whipple’s disease was made based upon demonstration of PAS-positive macrophages in the mesenteric lymph node and duodenal biopsies. Antimicrobial therapy resulted in weight gain and resolution of abdominal pain and arthralgia at six months follow-up.

Whipple’s disease can be fatal without antibacterial therapy and it always needs to be considered in individuals presenting with any combination of abdominal pain, weight loss, and diarrhea in the background of nonspecific arthritis or arthralgia. Whipple’s disease must also be considered in adults presenting with mesenteric lymphadenitis. Review of CT scans may be helpful, as Whipple’s disease characteristically causes low attenuation mesenteric lymphadenopathy.

Magnetic resonance enterography in pediatric celiac disease

OBJECTIVE

To assess if magnetic resonance enterography is capable of showing evidence/extent of disease in pediatric patients with biopsy-proven celiac disease by comparing with a control group, and to correlate the magnetic resonance enterography findings with anti-endomysial antibody level, which is an indicator of gluten-free dietary compliance.

METHODS

Thirty-one pediatric patients (mean age 11.7±3.1 years) with biopsy-proven celiac disease and 40 pediatric patients as a control group were recruited in the study. The magnetic resonance enterography images of both patients with celiac disease and those of the control group were evaluated by two pediatric radiologists in a blinded manner for the mucosal pattern, presence of wall thickening, luminal distention of the small bowel, and extra-intestinal findings. Patient charts were reviewed to note clinical features and laboratory findings. The histopathologic review of the duodenal biopsies was re-conducted.

RESULTS

The mean duration of the disease was 5.6±1.8 years (range: 3-7.2 years). In 24 (77%) of the patients, anti-endomysial antibody levels were elevated (mean 119.2±66.6RU/mL). Magnetic resonance enterography revealed normal fold pattern in all the patients. Ten (32%) patients had enlarged mesenteric lymph nodes.

CONCLUSION

Although a majority of the patients had elevated anti-endomysial antibody levels indicating poor dietary compliance, magnetic resonance enterography did not show any mucosal abnormality associated with the inability of magnetic resonance enterography to detect mild/early changes of celiac disease in children. Therefore, it may not be useful for the follow-up of pediatric celiac disease.