The Importance of Early Detection and Minimally Invasive Treatment of Pseudoaneurysms Due to Chronic Pancreatitis: Case Report.

The occurrence of the pseudoaneurysm of visceral arteries in the field of chronic pancreatitis is a very rare complication that represents a life-threatening condition. The higher frequency of this complication is in the necrotic form of pancreatic inflammation, especially in patients with formed peripancreatic necrotic collections. The degradation of the arterial wall leads to bleeding and transforms these necrotic collections into a pseudoaneurysm. Urgent endovascular angioembolization is the first choice in the therapeutic approach as a valid minimally invasive solution with very satisfactory immediate and long-term outcomes. This successfully avoids open surgery, which is associated with a high mortality rate in these patients, especially in acute-on-chronic pancreatitis.

Impact of prolonged liver ischemia during intermittent Pringle maneuver on postoperative outcome following liver resection.

BACKGROUND: The aim of this study was to compare postoperative outcomes following liver resection between patients with prolonged cumulative ischemia time (CIT) which exceeded 60 min and patients with CIT less than 60 min. METHODS: Between March 2020 and October 2022, 164 consecutive patients underwent liver resection at the Unit for hepato-bilio-pancreatic surgery, University Clinic for Digestive Surgery in Belgrade, Serbia. Intermittent Pringle maneuver was routinely applied. Depending on CIT during transection, patients were divided into two groups: group 1 (CIT <60 min) included 101 patients, and group 2 (CIT ≥60 min) included 63 patients. RESULTS: Median operative time (210 vs. 400 min) and CIT (30 vs. 76 min) were longer in the Group 2 (p < 0.001). Intraoperative blood loss was higher in the Group 2 (150 vs 500 ml), p < 0.001. The perioperative transfusion rate was similar between the groups (p = 0.107). There was no difference in postoperative overall morbidity (50.5% vs. 58.7%, p = 0.337) and major morbidity (18.8 vs. 19%, p = 0.401). In-hospital mortality, 30-day mortality, and 90-day mortality were similar between the groups (p = 0.408; p = 0.408; p = 0.252, respectively). Non-anatomical liver resection was the only predictive factor of 90-day mortality identified by multivariate analysis (p = 0.047; Relative Risk = 0.179; 95% Confidence Interval 0.033-0.981). CONCLUSION: Intermittent Pringle maneuver with CIT exceeding 60 min is a safe method for bleeding control during liver resection with no impact on postoperative morbidity and mortality.

"Bezoar Egg"-A Rare Cause of Small Bowel Obstruction.

Small bowel obstruction is a frequent medical condition with various causes, the most common being postoperative adhesions, volvulus, intussusception, hernias, and tumors. A bezoar-induced blockage of the small intestine is a rare condition that accounts for approximately 4% of all small bowel obstruction cases. Herein, we present the case report of a 71-year-old patient with diffuse abdominal pain caused by a small bowel obstruction due to a calcified bezoar (bezoar egg) resulting from a post-radiation intestinal stricture. The patient underwent a small bowel excision with the extraction of the bezoar, after which a full recovery was made.

CT and 18FDG-PET/CT findings in progressive mediastinal idiopathic fibrosis as a benign mimicker of esophageal carcinoma: a case report.

Idiopathic mediastinal fibrosis, also called sclerosing or fibrosing mediastinitis, is a very rare and aggressive fibroinflammatory process characterized by fibrous tissue proliferation in the mediastinal region. Herein, we present a rare case of idiopathic mediastinal fibrosis presenting with esophageal obstruction, most likely associated with immunoglobulin G (IgG4)-related disease, affecting the posterior mediastinum with intrapulmonary infiltration. Computed tomography revealed a narrowed lumen and thickened wall of the distal esophagus surrounded by a necrotic mass with infiltration into the nearby structures, suggesting a locally advanced malignant process. Positron emission tomography revealed intense accumulation of 18F-fluorodeoxyglucose, indicating an active inflammatory component, which complicates further differential diagnosis of mediastinal masses. Thoracoscopic biopsy and immunohistochemical analysis confirmed a fibroinflammatory process with perivascular lymphoid cell infiltration that was cluster of differentiation (CD)3 (++) and CD20 (++), with massive numbers of IgG4-immunoreactive plasma cells. Although a benign condition, sclerosing mediastinitis is a close mimicker of esophageal carcinoma, which cannot be differentiated by computed tomography or positron emission tomography and must be considered in a differential diagnosis.

MRI Tumor Regression Grade Combined with T2-Weighted Volumetry May Predict Histopathological Response in Locally Advanced Rectal Cancer following Neoadjuvant Chemoradiotherapy-A New Scoring System Proposal.

Modern studies focus on the discovery of innovative methods to improve the value of post-treatment magnetic resonance imaging (MRI) in the prediction of pathological responses to preoperative neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer (LARC). The aim of this study was to assess the potential benefits of combining magnetic resonance tumor regression grade (mrTRG) with T2-weighted volumetry in the prediction of pathological responses to nCRT in LARC. This was a cohort study conducted on patients with histopathologically confirmed LARC in a period from 2020 to 2022. After histopathological verification, all patients underwent initial MRI studies, while the follow-up MRI was performed after nCRT. Tumor characteristics, MRI estimated tumor regression grade (mrTRG) and tumor volumetry were evaluated both initially and at follow-up. All patients were classified into responders and non-responders according to pathological tumor regression grade (pTRG) and mrTRG. A total of 71 patients, mostly male (66.2%) were included in the study. The median tumor volume reduction rate was significantly higher in nCRT-responders compared to non-responders (79.9% vs. 63.3%) (p = 0.003). Based on ROC analysis, optimal cut-off value for tumor volume reduction rate was determined with an area under the curve (AUC) value of 0.724 (p = 0.003). Using the tumor volume reduction rate ≥75% with the addition of response to nCRT according to mrTRG, a new scoring system for prediction of pTRG to preoperative nCRT in LARC was developed. Diagnostic performance of prediction score was tested and the sensitivity, PPV, specificity, and NPV were 81.8%, 56.3%, 71.4%, and 89.7%, respectively. The combination of mrTRG and T2-weighted volumetry increases the MRI-based prediction of pTRG to preoperative nCRT in LARC. The proposed scoring system could aid in distinguishing responders to nCRT, as these patients could benefit from organ-preserving treatment and a "watch and wait" strategy.

The Role of MRI in the Diagnosis of Solid Pseudopapillary Neoplasm of the Pancreas and Its Mimickers: A Case-Based Review with Emphasis on Differential Diagnosis.

Solid pseudopapillary neoplasm (SPN) is rare pancreatic tumor occurring most commonly in young females. The typical imaging appearance of SPN is of well-defined, encapsulated, and large heterogeneous tumors, consisting of solid and cystic components due to various degrees of intralesional hemorrhage and necrosis. However, atypical imaging presentation in the form of small solid tumors or uniformly cystic lesions might also be seen, which can be explained by specific pathological characteristics. Other imaging features such as a round shape, the absence of main pancreatic duct dilatation, and slow growth, in combination with vague symptoms, favor the diagnosis of SPNs. Nevertheless, the radiological findings of SPN might overlap with other solid and cystic pancreatic neoplasms, such as neuroendocrine tumors, serous and mucinous neoplasms, and even small pancreatic adenocarcinomas. In addition, a few benign non-tumorous conditions including walled-of-necrosis, and intrapancreatic accessory spleen may also pose diagnostic dilemmas simulating SPNs on imaging studies. The aim of this manuscript is to provide a comprehensive overview of the typical and atypical imaging features of SPNs and to describe useful tips for differential diagnosis with its potential mimickers.

Directionally Sensitive Fractal Radiomics Compatible With Irregularly Shaped Magnetic Resonance Tumor Regions of Interest: Association With Osteosarcoma Chemoresistance.

BACKGROUND: Computational analysis of routinely acquired MRI has potential to improve the tumor chemoresistance prediction and to provide decision support in precision medicine, which may extend patient survival. Most radiomic analytical methods are compatible only with rectangular regions of interest (ROIs) and irregular tumor shape is therefore an important limitation. Furthermore, the currently used analytical methods are not directionally sensitive. PURPOSE: To implement a tumor analysis that is directionally sensitive and compatible with irregularly shaped ROIs. STUDY TYPE: Retrospective. SUBJECTS: A total of 54 patients with histopathologic diagnosis of primary osteosarcoma on tubular long bones and with prechemotherapy MRI. FIELD STRENGTH/SEQUENCE: A 1.5 T, T2-weighted-short-tau-inversion-recovery-fast-spin-echo. ASSESSMENT: A model to explore associations with osteosarcoma chemo-responsiveness included MRI data obtained before OsteoSa MAP neoadjuvant cytotoxic chemotherapy. Osteosarcoma morphology was analyzed in the MRI data by calculation of the nondirectional two-dimensional (2D) and directional and nondirectional one-dimensional (1D) Higuchi dimensions (Dh). MAP chemotherapy response was assessed by histopathological necrosis. STATISTICAL TESTS: The area under the receiver operating characteristic (ROC) curve (AUC) evaluated the association of the calculated features with the actual chemoresponsiveness, using tumor histopathological necrosis (95%) as the endpoint. Least absolute shrinkage and selection operator (LASSO) machine learning and multivariable regression were used for feature selection. Significance was set at <0.05. RESULTS: The nondirectional 1D Dh reached an AUC of 0.88 in association with the 95% tumor necrosis, while the directional 1D analysis along 180 radial lines significantly improved this association according to the Hanley/McNeil test, reaching an AUC of 0.95. The model defined by variable selection using LASSO reached an AUC of 0.98. The directional analysis showed an optimal predictive range between 90° and 97° and revealed structural osteosarcoma anisotropy manifested by its directionally dependent textural properties. DATA CONCLUSION: Directionally sensitive radiomics had superior predictive performance in comparison to the standard nondirectional image analysis algorithms with AUCs reaching 0.95 and full compatibility with irregularly shaped ROIs. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 1.

Hepatocellular Carcinoma Presenting Simultaneously with Echinococcal Cyst Mimicking a Single Liver Lesion in a Non-Cirrhotic Patient: A Case Report and Review of the Literature.

A coexistance of liver cystic echinococcosis (CE) and hepatocellular carcinoma (HCC) is very rare. HCC is the leading cause of cancer-related mortality worldwide, while CE is a globally endemic zoonosis caused by the cestode tapeworm Echinococcus granulosus. The association between these two diseases is still not well-defined. A preoperative diagnosis may be challenging, especially if HCC and CE present as a single lesion and if atypical imaging features are present. Herein, we present a case of the patient that was initially diagnosed as an extensive necrotic tumor in the left liver lobe and highly suspicious of being HCC associated with peritumoral hematoma. Left hemihepatectomy was performed, and the histopathological findings showed the collision of two lesions: a hydatid cyst and HCC.

Imaging Spectrum of Intrahepatic Mass-Forming Cholangiocarcinoma and Its Mimickers: How to Differentiate Them Using MRI.

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary hepatic malignancy, with mass-forming growth pattern being the most common. The typical imaging appearance of mass-forming ICC (mICC) consists of irregular ring enhancement in the arterial phase followed by the progressive central enhancement on portal venous and delayed phases. However, atypical imaging presentation in the form of hypervascular mICC might also be seen, which can be attributed to distinct pathological characteristics. Ancillary imaging features such as lobular shape, capsular retraction, segmental biliary dilatation, and vascular encasement favor the diagnosis of mICC. Nevertheless, these radiological findings may also be present in certain benign conditions such as focal confluent fibrosis, sclerosing hemangioma, organizing hepatic abscess, or the pseudosolid form of hydatid disease. In addition, a few malignant lesions including primary liver lymphoma, hemangioendothelioma, solitary hypovascular liver metastases, and atypical forms of hepatocellular carcinoma (HCC), such as scirrhous HCC, infiltrative HCC, and poorly differentiated HCC, may also pose a diagnostic dilemma by simulating mICC in imaging studies. Diffusion-weighted imaging and the use of hepatobiliary contrast agents might be helpful for differential diagnosis in certain cases. The aim of this manuscript is to provide a comprehensive overview of mICC imaging features and to describe useful tips for differential diagnosis with its potential mimickers.

An overview of hepatocellular carcinoma with atypical enhancement pattern: spectrum of magnetic resonance imaging findings with pathologic correlation.

BACKGROUND: In the setting of cirrhotic liver, the diagnosis of hepatocellular carcinoma (HCC) is straightforward when typical imaging findings consisting of arterial hypervascularity followed by portal-venous washout are present in nodules larger than 1 cm. However, due to the complexity of hepatocarcinogenesis, not all HCCs present with typical vascular behaviour. Atypical forms such as hypervascular HCC without washout, isovascular or even hypovascular HCC can pose diagnostic dilemmas. In such cases, it is important to consider also the appearance of the nodules on diffusion-weighted imaging and hepatobiliary phase. In this regard, diffusion restriction and hypointensity on hepatobiliary phase are suggestive of malignancy. If both findings are present in hypervascular lesion without washout, or even in iso- or hypovascular lesion in cirrhotic liver, HCC should be considered. Moreover, other ancillary imaging findings such as the presence of the capsule, fat content, signal intensity on T2-weighted image favour the diagnosis of HCC. Another form of atypical HCCs are lesions which show hyperintensity on hepatobiliary phase. Therefore, the aim of the present study was to provide an overview of HCCs with atypical enhancement pattern, and focus on their magnetic resonance imaging (MRI) features. CONCLUSIONS: In order to correctly characterize atypical HCC lesions in cirrhotic liver it is important to consider not only vascular behaviour of the nodule, but also ancillary MRI features, such as diffusion restriction, hepatobiliary phase hypointensity, and T2-weighted hyperintensity. Fat content, corona enhancement, mosaic architecture are other MRI feautures which favour the diagnosis of HCC even in the absence of typical vascular profile.

The role of quantitative diffusion-weighted imaging in characterization of hypovascular liver lesions: A prospective comparison of intravoxel incoherent motion derived parameters and apparent diffusion coefficient.

BACKGROUND: The utility of intravoxel incoherent motion (IVIM) related parameters in differentiation of hypovascular liver lesions is still unknown. PURPOSE: The purpose of this study was to evaluate the value of IVIM related parameters in comparison to apparent diffusion coefficient (ADC) for differentiation among intrahepatic mass-forming cholangiocarcinoma (IMC), and hypovascular liver metastases (HLM). METHODS: Seventy-four prospectively enrolled patients (21 IMC, and 53 HLM) underwent 1.5T magnetic resonance examination with IVIM diffusion-weighted imaging using seven b values (0-800 s/mm2). Two independent readers performed quantitative analysis of IVIM-related parameters and ADC. Interobserver reliability was tested using a intraclass correlation coefficient. ADC, true diffusion coefficient (D), perfusion-related diffusion coefficient (D*), and perfusion fraction (ƒ) were compared among the lesions using Kruskal-Wallis H test. The diagnostic accuracy of each parameter was assessed by receiver operating characteristic (ROC) curve analysis. RESULTS: The interobserver agreement was good for ADC (0.802), and excellent for D, D*, and ƒ (0.911, 0.927, and 0.942, respectively). ADC, and D values were significantly different among IMC and HLM (both p < 0.05), while there was no significant difference among these lesions for ƒ and D* (p = 0.101, and p = 0.612, respectively). ROC analysis showed higher diagnostic performance of D in comparison to ADC (AUC = 0.879 vs 0.821). CONCLUSION: IVIM-derived parameters in particular D, in addition to ADC, could help in differentiation between most common hypovascular malignant liver lesions, intrahepatic mass-forming cholangiocarcinoma and hypovascular liver metastases.

Comparison of Preoperative Evaluation with the Pathological Report in Intraductal Papillary Mucinous Neoplasms: A Single-Center Experience.

The key to the successful management of pancreatic cystic neoplasm (PCN), among which intraductal papillary mucinous neoplasm (IPMN) is the one with the highest risk of advanced neoplasia in resected patients, is a careful combination of clinical, radiological, and histopathological findings. This study aims to perform the comparison of a preoperative evaluation with pathological reports in IPMN and further, to evaluate and compare the diagnostic performance of European evidence-based guidelines on pancreatic cystic neoplasms (EEBGPCN) and Fukuoka Consensus guidelines (FCG). We analyzed 106 consecutive patients diagnosed with different types of PCN, among whom 68 had IPMN diagnosis, at the Clinical Center of Serbia. All the patients diagnosed with IPMNs were stratified concerning the presence of the absolute and relative indications according to EEBGPCN and high-risk stigmata and worrisome features according to FCG. Final histopathology revealed that IPMNs patients were further divided into malignant (50 patients) and benign (18 patients) groups, according to the pathological findings. The preoperative prediction of malignancy according to EEBGPCN criteria was higher than 70% with high sensitivity of at least one absolute or relative indication for resection. The diagnostic performance of FCG was shown as comparable to EEBGPCN. Nevertheless, the value of false-positive rate for surgical resection showed that in some cases, overtreating patients or treating them too early cannot be prevented. A multidisciplinary approach is essential to adequately select patients for the resection considering at the same time both the risks of surgery and malignancy.

Low-grade fibromyxoid sarcoma of the liver: A case report.

BACKGROUND: Low grade fibromyxoid sarcoma (LGFMS) is a rare and benign mesenchymal tumor with indolent course, most commonly found in young or middle-aged men. The majority of the LGFMSs are located in the trunk and deep soft tissue of the lower extremities. They appear as well circumscribed, although not encapsulated, which often leads to incomplete surgical resection. Despite their seemingly benign appearance, these tumors have aggressive behavior with high metastatic and recurrence rates. Accurate histopathologic examination of the specimen and its immunohistochemical analysis are mandatory for a precise diagnosis. CASE SUMMARY: We report a case of a 38 year-old-man who presented with jaundice and upper abdominal discomfort. Multi-detector computed tomography and magnetic resonance imaging showed a large left liver tumor mass, extending to the hepatoduodenal ligament. Left hepatectomy was performed with resection and reconstruction of hepatic artery and preservation of middle hepatic vein. Histopathologic examination confirmed the tumor being a low-grade fibromyxoid sarcoma. Three and a half years after surgery, the patient died after being diagnosed with spine metastasis. CONCLUSION: Due to poor response to all modalities of adjuvant treatment, we consider that the focus of treatment should be on surgery as the only option for curing the disease.

Pearls and pitfalls in magnetic resonance imaging of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the most common primary hepatic malignancy, which usually arises in cirrhotic liver. When the typical enhancement pattern, consisting of late arterial hyperenhancement followed by washout, is present in nodules larger than 1 cm, HCC can be confidently diagnosed without the need for tissue biopsy. Nevertheless, HCC can display an atypical enhancement pattern, either as iso or hypovascular lesion, or hypervascular lesion without washout. Not only the enhancement pattern of HCC could be atypical, but also a variety of histological types of HCC, such as steatotic, scirrhous, fibrolamellar, or combined hepatocellular-cholangiocellular carcinoma could raise diagnostic dilemmas. In addition, distinct morphological types of HCC or different growth pattern can occur. Awareness of these atypical and rare HCC presentations on magnetic resonance imaging is important for accurate differentiation from other focal liver lesions and timely diagnosis, which allows optimal treatment of patients.

The Time to and Type of Pancreatic Cancer Recurrence after Surgical Resection: Is Prediction Possible?

RATIONALE AND OBJECTIVES: To evaluate factors predicting pancreatic cancer recurrence, and to determine the most common appearance of tumor relapse. MATERIALS AND METHODS: Ninety patients with recurrent pancreatic cancer were retrospectively included in the study. 74.4% had pancreatic head tumors (group 1) and 25.6% pancreatic body and/or tail tumor (group 2). The tumor localization, operative technique, TNM stage, the R-status, tumor grade, lymphovascular, and perineural invasion were recorded. Location of local tumor recurrence, lymph node recurrence, or organ metastases were analyzed on the basis of follow-up CT imaging. RESULTS: Mean recurrence time was 17.4 ± 13.2 months. The most common recurrence type was local recurrence (84.4%), followed by lymph node (15.5%), liver (14.4%), and lung metastasis (6.7%). The predominant site of local recurrence in pancreatic head tumors was close to superior mesenteric artery, common hepatic artery, and/or celiac artery (57.4%), followed by area defined by portal vein, inferior vena cava, CA or superior mesenteric artery (31.2%). Patients with pancreatic body and/or tail carcinoma had higher incidence (p = 0.003) of metastatic disease comparing to pancreatic head tumors, while resection margin was the most common type of local tumor recurrence, seen in 46.7% cases versus 8.2% of patients with pancreatic head tumors (p < 0.001). CONCLUSION: The most common recurrence type in patients with resected pancreatic carcinoma was local recurrence along cardinal arteries. The localization of primary tumor influences the type of tumor relapse and site of local recurrence.