Role of contrast-enhanced endoscopic ultrasound in lymph nodes

Gastric cancer in 2022: Is there still a role for endoscopic ultrasound?

Gastric cancer (GC) represents the fourth leading cause of cancer death worldwide and many factors can influence its development (diet, geographic area, genetic, Helicobacter pylori or Epstein-Barr virus infections). High quality endoscopy represents the modality of choice for GC diagnosis. The correct morphologic classification during a high-resolution endoscopy is fundamental for oncologic diagnosis, staging and therapeutic decisions. Since its initial introduction in clinical practice the endoscopic ultrasound (EUS) has been considered a valuable tool for tumor (T-) and lymph nodes (N-) staging also in GC, in order to establish the best therapeutic strategy for the patient (e.g., upfront surgery vs neoadjuvant treatments). EUS tools as elastography, Doppler and contrast administration can improve diagnosis mainly in case of malignant lymph node evaluation. EUS has a marginal role in disease staging but has a fundamental role in case of a pre-endoscopic resection management and in the new era of endoscopic mucosal resection or submucosal dissection as minimally invasive surgery. Diagnosis and locoregional staging of GC with EUS are a method of inarguable value for the assessment of gastric wall involvement and presence of infiltrated paragastric lymph nodes. EUS can also have a role in disease restaging in those patients who have undergone neoadjuvant treatment. EUS can also have a role in the advanced phases of the disease, in facilitating palliative, minimally-invasive treatments, such as gastroenterostomy or biliary drainages. This review intends to discuss the modern role of EUS in GC topic.

Endoscopic ultrasound assessment and tissue acquisition of mediastinal and abdominal lymph nodes

The differential diagnosis between benign and malignant lymph nodes (LNs) has a fundamental role in the characterization and staging of malignant conditions, as well as in subsequent patients’ management. All imaging modalities (i.e. computed tomography and magnetic resonance imaging) rely mainly on size; endoscopic ultrasound (EUS) criteria based on B-mode evaluation and Doppler features fail to adequately characterize with high specificity LNs nature. The introduction of EUS-elastography and contrast-enhanced harmonic EUS are useful techniques to increase the diagnostic yield in identifying metastatic LNs, to identify which suspicious LN should require pathological characterization and, finally, to target tissue acquisition. EUS-guided tissue acquisition (EUS-TA) is increasingly being used for diagnosing lymphadenopathy whenever the characterization modifies patients’ subsequent management and when no superficial LN is accessible. Since target therapy are currently available (i.e. lung cancer, breast cancer), EUS-TA of malignant LNs could be required to identify tumor biology. In this field, both fine needle aspiration and biopsy needles are able to guarantee accurate results with almost perfect specificity and sub-optimal sensitivity. We finally propose a diagnostic algorithm based on most recent, high-level evidence for the diagnostic approach to suspected LNs assessment.

Mediastinal Masses in Contrast-Enhanced Ultrasound - Retrospective Analysis of 58 Cases

OBJECTIVES

To determine contrast enhancing features of mediastinal masses (ML) using transcutaneous contrast-enhanced ultrasound (CEUS).

METHODS

Retrospective analysis of n = 58 patients with histologically confirmed ML, which were examined in the period from October 2005 to February 2018 using transcutaneous B-mode ultrasound and CEUS. In n = 29 (50%) histological confirmation was performed by ultrasound guided core-needle biopsy. The lesions were evaluated using CEUS in regard to the enhancement pattern (hyper-, iso-, hypoenhancement, non-enhancement, homogenous, inhomogenous) compared to enhancement of the spleen as an in vivo reference.

RESULTS

N = 53 (91.4%) of ML were malignant (m) (lymphoma n = 36, metastasis n = 11, thymoma n = 2, teratoma n = 1, sarcoma n = 2, seminoma n = 1). In n = 5 (8.6%) cases there was a benign (b) histology (thyroid tissue n = 2, thymus residue n = 1, ganglioneurinoma n = 1, scar tissue: n = 1). In ultrasound, n = 53 (91.4%; (48 = m, 5 = b)) were hypoechoic, n = 5 (8.6%, (5 = m,0 = b)) hyperechoic. In CEUS, n = 35 lesions presented an arterial isoenhancement (60.3%; 33 = m, 2 = b). An arterial hypoenhancement had n = 21 (36.2%, (20 = m,1 = b)), and no enhancement showed n = 2 (3.5%, (0 = m, 2 = b) of the ML. A parenchymal isoenhancement was observed in n = 1 (1.7%, (1 = m, 0 = b)), a hypoenhancement in n = 54 (93.1%; 51 = m, 3 = b) of the patients and almost no enhancement in n = 3 ML (5.2%, (1 = m, 2 = b).) The enhancement was homogeneous in n = 26 (44.8%, (25 = m,1 = b)) cases, in n = 31 (53.5%, (28 = m,3 = b)) inhomogeneous and n = 1 (1.7%) benign lesion was exclusively cystic.

CONCLUSION

In CEUS, mediastinal tumor formations showed variable arterial enhancement, followed by parenchymal hypoenhancement (wash-out).

Do we need contrast agents for EUS?

We recently introduced a series of articles that dealt with controversies in EUS. In Part I, the authors discussed which clinical information is necessary prior to EUS and whether other imaging modalities are required before embarking on EUS examinations. Part II focuses on technical details and controversies about the use of EUS in special situations. In this article, important practical issues regarding the application of contrast-enhanced EUS in various clinical settings are raised and controversially discussed from different points of view.

shRNA-interfering LSD1 inhibits proliferation and invasion of gastric cancer cells via VEGF-C/PI3K/AKT signaling pathway

BACKGROUND

Histone Lysine Specific Demethylase 1 (LSD1) is the first histone demethylase to be discovered, which regulates various biological functions by making lysine of histone H3K4, H3K9 and non-histone substrates demethylated. Abnormal regulation of LSD1 is closely related to the occurrence and development of gastric cancer. The change of LSD1 expression level plays an important role in the proliferation and metastasis of gastric cancer cells. The study of its function and mechanism may provide a theoretical basis for early diagnosis and targeted therapy of gastric cancer.

AIM

To investigate the effect of downregulation of lysine-specific demethylase 1 (LSD1) expression on proliferation and invasion of gastric cancer cells and the possible regulatory mechanisms of the VEGF-C/PI3K/AKT signaling pathway.

METHODS

The LSD1-specific short hairpin RNA (shRNA) interference plasmid was transiently transfected, and expression of LSD1 was downregulated. The cell proliferation ability of LSD1 was observed by CCK-8 assay after downregulating expression of LSD1. Transwell invasion assay was used to observe the change of cell invasion ability after downregulating expression of LSD1. Expression of phosphorylated phosphoinositide 3-kinase (p-PI3K), PI3K, p-AKT, AKT, vascular endothelial growth factor receptor (VEGFR)-3, matrix metalloproteinase (MMP)-2 and MMP-9 in each group was detected by Western blotting.

RESULTS

The cell proliferation ability of transiently transfected LSD1-shRNA interference plasmid group was significantly lower than that of the control group (P < 0.05). Transwell invasion assay showed that the number of cells across the membrane of the LSD1-shRNA transfection group (238.451 ± 5.216) was significantly lower than that of the control group (49.268 ± 6.984) (P < 0.01). Western blotting showed that expression level of VEGF-C, p-PI3K, PI3K, p-AKT, AKT, VEGFR-3, MMP-2 and MMP-9 in the LSD1-shRNA group was significantly lower than that in the control group (P < 0.05).

CONCLUSION

Downregulation of LSD1 expression inhibits metastatic potential of gastric cancer cells, and VEGF-C-mediated activation of PI3K/AKT signaling pathway, which may be an important mechanism for inhibiting lymph node metastasis in gastric cancer cells.

[Capabilities of contrast-enhanced ultrasound for preoperative assessment of regional lymphatic basin in patients with early oral cavity squamous cell cancer]

This review paper describes the possibilities of visualization of regional lymph nodes using contrast-enhanced ultrasound. Discussed is the experience of contrast-enhanced ultrasound implication for differential diagnosis of regional metastases of squamous cell carcinoma of the oral mucosa. The basics of the technique of contrast-enhanced ultrasound examination of the neck lymphatic basin are described.

Elastography of the Pancreas, Current View

Ultrasound elastography (USE) of the pancreas allows pancreatic tissue stiffness assessment by virtual palpation. Two main types of USE are used. For the pancreas strain elastography applying by endoscopic ultrasound has been established for the characterisation of small solid pancreatic lesions (SPL). In larger SPL >30 mm the results are less convincing mainly due to the heterogenicity of the lesions but also by concomitant changes of the surrounding pancreatic parenchyma. The current role of shear wave elastography has to be determined. This article reviews the current use of elastography of the pancreas.

Review of Dancing Parasites in Lymphatic Filariasis

Lymphatic filariasis is an infection transmitted by blood-sucking mosquitoes with filarial nematodes of the species Wuchereria bancrofti, Brugia malayi und B. timori . It is prevalent in tropical countries throughout the world, with more than 60 million people infected and more than 1 billion living in areas with the risk of transmission. Worm larvae with a length of less than 1 mm are transmitted by mosquitoes, develop in human lymphatic tissue to adult worms with a length of 7-10 cm, live in the human body for up to 10 years and produce millions of microfilariae, which can be transmitted further by mosquitoes. The adult worms can be easily observed by ultrasonography because of their size and fast movements (the so-called "filarial dance sign"), which can be differentiated from other movements (e. g., blood in venous vessels) by their characteristic movement profile in pulsed-wave Doppler mode. Therapeutic options include (combinations of) ivermectin, albendazole, diethylcarbamazine and doxycycline. The latter depletes endosymbiotic Wolbachia bacteria from the worms and thus sterilizes and later kills the adult worms (macrofilaricidal or adulticidal effect).

Lysyl oxidase and hypoxia-inducible factor 1α: biomarkers of gastric cancer

BACKGROUND

Gastric cancer (GC) is one of the main causes of cancer mortality worldwide. Recent studies on tumor microenvironments have shown that tumor metabolism exerts a vital role in cancer progression.

AIM

To investigate whether lysyl oxidase (LOX) and hypoxia-inducible factor 1α (HIF1α) are prognostic and predictive biomarkers in GC.

METHODS

A total of 80 tissue and blood samples were collected from 140 patients admitted to our hospital between August 2008 and March 2012. Immunohistochemical staining was performed to measure the expression of LOX and HIF1α in tumor and adjacent tissues collected from patients with GC. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis was used to detect the mRNA expression levels of LOX and HIF1α in patients with GC. In addition, single-factor analysis was applied to analyze the relationship between LOX, HIF1α and prognosis of GC.

RESULTS

Immunohistochemical staining suggested that the expression levels of LOX and HIF1α increased in tumor tissues from patients with GC. QRT-PCR analysis indicated that mRNA expression of LOX and HIF1α was also upregulated in tumor tissues, which was in accordance with the above results. We also detected expression of these two genes in blood samples. The expression level of LOX and HIF1α was higher in patients with GC than in healthy controls. Additional analysis showed that the expression level of LOX and HIF1α was related to the clinicopathological characteristics of GC. Expression of LOX and HIF1α increased with the number of lymph node metastases, deeper infiltration depth and later tumor–node–metastasis stages. Single-factor analysis showed that high expression of LOX and HIF1α led to poor prognosis of patients with GC.

CONCLUSION

LOX and HIF1α can be used as prognostic and predictive biomarkers for GC.

Contrast-enhanced endoscopic ultrasound for the differential diagnosis between benign and malignant lymph nodes: a meta-analysis

Background  The differential diagnosis between benign and malignant lymph nodes (LNs) is crucial for patient management and clinical outcome. The use of contrast-enhanced endoscopic ultrasound (EUS) has been evaluated in several studies with diverse results. The aim of this meta-analysis was to evaluate the pooled diagnostic accuracy of contrast-enhanced EUS (CE-EUS) and contrast-enhanced harmonic EUS (CH-EUS) in this setting. Methods  A systematic electronic search was performed, including all original papers dealing with assessment of the nature of the LNs using CE-EUS or CH-EUS. A meta-analysis was performed to obtain pooled sensitivity, specificity, positive and negative likelihood ratio, and diagnostic odds ratio. The Summary Receiver Operating Characteristic (ROC) Curve method was used to calculate the area under the curve. Statistical analysis was carried out using Meta-Disc V.1.4, Stata V.12.0 and Review Manager V.5.2. Results  Among 210 pertinent studies, four (336 patients) were included in the analysis. The pooled sensitivity was 82.1 % (75.1 - 87.7 %) and pooled specificity was 90.7 % (85.9 - 94.3 %) with significant heterogeneity found in sensitivity; the positive-likelihood ratio (LR) was 7.77 (5.09 - 11.85) and the negative-LR was 0.15 (0.05 - 0.46); the pooled diagnostic odds ratio (DOR) was 54 (15 - 190). Subgroup analysis including studies performed using CH-EUS (two studies, 177 LNs) showed a pooled sensitivity of 87.7 % (77.0 - 93.9 %) and a pooled specificity of 91.8 % (84.5 % - 96.4 %) with no significant heterogeneity; the pooled positive-LR was 9.51 (4.95 - 18.28) and the pooled negative-LR was 0.14 (0.06 - 0.35); pooled DOR was 68.42 (15.5 - 301.4). Conclusions  From these data, CE-EUS is not recommended due to inadequate sensitivity. On the other hand, CH-EUS studies showed optimal accuracy (pooled sensitivity 87.7 % and specificity 91.8 %), comparable to elastography and even EUS-guided fine needle aspiration (EUS-FNA), suggesting a role in the diagnostic algorithm.

Predictive Factors for Inaccurate Diagnosis of Swollen Lymph Nodes in Endoscopic Ultrasound-Guided Fine Needle Aspiration

Background/Aims

This study aimed to identify the predictive factors for inaccurate endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) diagnosis of swollen lymph nodes without rapid on-site cytopathological evaluation.

Methods

Eighty-three consecutive patients who underwent EUS-FNA for abdominal or mediastinal lymph nodes from January 2008 to June 2017 were included from a prospectively maintained EUS-FNA database and retrospectively reviewed. The sensitivity, specificity, and accuracy of EUS-FNA for the detection of neoplastic diseases were calculated. Candidate factors for inaccurate diagnosis (lymph node size and location, needle type, puncture route, number of passes, and causative disease) were evaluated by comparison between accurately diagnosed cases and others.

Results

The final diagnosis of the punctured lymph node was classified as neoplastic (65 cases: a metastatic lymph node, malignant lymphoma, or Crow-Fukase syndrome) or non-neoplastic (18 cases: a reactive node or amyloidosis). The sensitivity, specificity, and accuracy were 83%, 94%, and 86%, respectively. On multivariate analyses, small size of the lymph node was the sole predictive factor for inaccurate EUS-FNA diagnosis with a significant difference (odds ratios, 19.8; 95% confidence intervals, 3.15–124; p=0.0015).

Conclusions

The lymph node size of <16 mm was the only independent factor associated with inaccurate EUS-FNA diagnosis of swollen lymph nodes.

Ultrasound findings in autoimmune hepatitis

Ultrasound findings in autoimmune hepatitis (AIH) have not been reported systematically so far. The use of reliable and accurate noninvasive methods for determining fibrosis stage is important in evaluation of treatment efficacy and fibrosis regression in AIH. Imaging plays an important role in detection of complications and ruling out other possible causes of chronic liver diseases. Ultrasound elastography cut-off values in AIH patients are not the same as those in patients with chronic viral hepatitis or non-alcoholic fatty liver disease. AIH is characterized by wide fluctuations in inflammatory activity. Here we report on current knowledge of ultrasound findings in AIH.

Serous pancreatic neoplasia, data and review

AIM

To describe the imaging features of serous neoplasms of the pancreas using ultrasound, endoscopic ultrasound, computed tomography and magnetic resonance imaging.

METHODS

This multicenter international collaboration enhances a literature review to date, reporting features of 287 histologically confirmed cases of serous pancreatic cystic neoplasms (SPNs).

RESULTS

Female predominance is seen with most SPNs presenting asymptomatically in the 5^th through 7^th decade. Mean lesion size was 38.7 mm, 98% were single, 44.2% cystic, 46% mixed cystic and solid, and 94% hypoechoic on B-mode ultrasound. Vascular patterns and contrast-enhancement profiles are described as hypervascular and hyperenhancing.

CONCLUSION

The described ultrasound features can aid differentiation of SPN from other neoplastic lesions under most circumstances.