Comparison of temporal evolution of computed tomography imaging features in COVID-19 and influenza infections in a multicenter cohort study.

Purpose: To compare temporal evolution of imaging features of coronavirus disease 2019 (COVID-19) and influenza in computed tomography and evaluate their predictive value for distinction. Methods: In this retrospective, multicenter study 179 CT examinations of 52 COVID-19 and 44 influenza critically ill patients were included. Lung involvement, main pattern (ground glass opacity, crazy paving, consolidation) and additional lung and chest findings were evaluated by two independent observers. Additional findings and clinical data were compared patient-wise. A decision tree analysis was performed to identify imaging features with predictive value in distinguishing both entities. Results: In contrast to influenza patients, lung involvement remains high in COVID-19 patients > 14 days after the diagnosis. The predominant pattern in COVID-19 evolves from ground glass at the beginning to consolidation in later disease. In influenza there is more consolidation at the beginning and overall less ground glass opacity (p = 0.002). Decision tree analysis yielded the following: Earlier in disease course, pleural effusion is a typical feature of influenza (p = 0.007) whereas ground glass opacities indicate COVID-19 (p = 0.04). In later disease, particularly more lung involvement (p < 0.001), but also less pleural (p = 0.005) and pericardial (p = 0.003) effusion favor COVID-19 over influenza. Regardless of time point, less lung involvement (p < 0.001), tree-in-bud (p = 0.002) and pericardial effusion (p = 0.01) make influenza more likely than COVID-19. Conclusions: This study identified differences in temporal evolution of imaging features between COVID-19 and influenza. These findings may help to distinguish both diseases in critically ill patients when laboratory findings are delayed or inconclusive.

Indeterminate dendritic cell tumor in the pancreas.

Indeterminate dendritic cell tumor (IDCT) is an extremely rare hematologic neoplastic disorder with proliferation of indeterminate dendritic cells. In the vast majority of cases, IDCTs are restricted to the skin or lymph nodes. To our knowledge, we report the first case of IDCT in the pancreas. Due to the rarity of extracutaneous IDCT, guidelines or treatment recommendations addressing their management are missing. We performed a review of literature to compare our experience to the management of other extracutaneous IDCT. Histopathological examination confirms the diagnosis of IDCT in electron microscopy and/or immunohistochemistry. Specific features are the lack of Birbeck granules and the nonreaction to Langerin antibodies. Concerning the aftercare of extracutaneous IDCT, we recommend a dermatological examination to rule out an additional cutaneous manifestation as well as annual blood examinations due to the association between IDCT and hematologic malignancies.

No difference in radiolucent lines after TKA: a matched-pair analysis of the classic implant and its evolutional design.

PURPOSE: Total knee arthroplasty (TKA) designs evolve continuously to improve patient outcomes. However, incidences of radiolucent lines (RLL) in the latest TKA system have recently been reported, raising concerns. The purpose of the current study was to compare radiographic outcomes of this new TKA implant to its predecessor design. METHODS: A group of 100 patients undergoing TKA using the newer design (Attune) was matched by age and gender to 191 patients with the classic design (LCS). All patients underwent computer-navigated primary TKA by the same surgeon using the same technique. Radiographs were taken before discharge, and 2 and 12 months postoperatively. Radiographic analysis was performed independently by three assessors, using the Modern Knee Society Radiographic Evaluation System and Methodology (MKSRES). RESULTS: At 12 months postoperatively, the incidence of RLL did not statistically differ between the two implants (14%, n = 14 Attune vs. 8% n = 17 LCS, n.s.). The posterior femoral flange was most commonly affected (12%; n = 12 Attune vs. 7.9%; n = 15 LCS, n.s.) followed by the anterior flange (1%; n = 1 Attune vs. 3.1%; n = 6 LCS, n.s.). The tibial baseplate was only affected in 1% (n = 1) of the Attune and 2.6% (n = 5) of the LCS (n.s.). CONCLUSION: At 12 months follow-up we found no significant difference in RLL between the two implants. Both Attune and LCS TKA systems showed RLL predominantly at the posterior femoral flange. The reasons for the RLL remain a matter of speculation; however, shortcomings in surgical and cementing techniques seem to be more important than implant-related factors. LEVEL OF EVIDENCE: III.