CT and FDG-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

The Utility of Conventional CT, CT Perfusion and Quantitative Diffusion-Weighted Imaging in Predicting the Risk Level of Gastrointestinal Stromal Tumors of the Stomach: A Prospective Comparison of Classical CT Features, CT Perfusion Values, Apparent Diffusion Coefficient and Intravoxel Incoherent Motion-Derived Parameters

Background: The role of advanced functional imaging techniques in prediction of pathological risk categories of gastrointestinal stromal tumors (GIST) is still unknown. The purpose of this study was to evaluate classical CT features, CT-perfusion and magnetic-resonance-diffusion-weighted-imaging (MR-DWI)-related parameters in predicting the metastatic risk of gastric GIST. Patients and methods: Sixty-two patients with histologically proven GIST who underwent CT perfusion and MR-DWI using multiple b-values were prospectively included. Morphological CT characteristics and CT-perfusion parameters of tumor were comparatively analyzed in the high-risk (HR) and low-risk (LR) GIST groups. Apparent diffusion coefficient (ADC) and intravoxel-incoherent-motion (IVIM)-related parameters were also analyzed in 45 and 34 patients, respectively. Results: Binary logistic regression analysis revealed that greater tumor diameter (p < 0.001), cystic structure (p < 0.001), irregular margins (p = 0.007), irregular shape (p < 0.001), disrupted mucosa (p < 0.001) and visible EFDV (p < 0.001), as well as less ADC value (p = 0.001) and shorter time-to-peak (p = 0.006), were significant predictors of HR GIST. Multivariate analysis extracted irregular shape (p = 0.006) and enlarged feeding or draining vessels (EFDV) (p = 0.017) as independent predictors of HR GIST (area under curve (AUC) of predicting model 0.869). Conclusion: Although certain classical CT imaging features remain most valuable, some functional imaging parameters may add the diagnostic value in preoperative prediction of HR gastric GIST

COVID-19-Associated Pulmonary Aspergillosis in Patients with Acute Leukemia: A Single-Center Study

Patients with coronavirus disease 19 (COVID-19) have increased susceptibility to secondary respiratory infections including invasive pulmonary aspergillosis (IPA). COVID-19-associated pulmonary aspergillosis (CAPA) is difficult to diagnose and can be associated with increased mortality especially in severe immunodeficiency such as hematological malignancies. Our study evaluates IPA in COVID-19 patients defined as COVID-19-CAPA among patients with acute leukemia (AL). A retrospective single-center study analyzed 46 patients with COVID-19 infection and acute leukemia, admitted to the Clinic for Haematology, Clinical Center of Serbia, Belgrade between the 2 April 2020 and 15 May 2021. During hospitalization, all participants were diagnosed with probable IPA according to the previous consensus definitions. Positive serology and galactomannan (GM) detection values in bronchoalveolar lavage (BAL) and serum were used as microbiological criteria. COVID-19 associated probable IPA was found in 22% (9/41) tested patients, where serum GM and IgM anti-Aspergillus antibodies were positive in 12% (5/41) and 10% (4/41) had positive serology for aspergillosis. One patient died while eight recovered during follow-up. Our study showed that COVID-19 might be a risk factor for IPA development in patients with AL. Early diagnosis and prompt treatment are required as reported mortality rates are high