Childhood and Adolescent Relapsed/Refractory Aggressive B-Cell Lymphomas With t(8;14) and BCL2 Expression, Burkitt Lymphoma Versus Diffuse Large B-Cell Lymphoma: A Diagnostic Challenge.

We present 2 diagnostically challenging cases of pediatric/adolescent relapsed/refractory aggressive mature B-cell non-Hodgkin lymphoma (B-NHL) within the spectrum of Burkitt lymphoma and diffuse large B-cell lymphoma and illustrate the different therapeutic regimens that are employed for pediatric and adult cancer centers. Both cases displayed varying-sized lymphoma cells with occasional single prominent nucleoli and heterogeneous BCL2 expression. Cytogenetics revealed complex karyotypes with t(8:14)(q24.2;q32) and IGH::MYC rearrangement by FISH. Next generation sequencing revealed deleterious TP53 and MYC mutations. We concluded that both could be diagnosed as "DLBCL-NOS with MYC rearrangement" using the current pathologic classifications, 2022 International Consensus Classification (ICC) and World Health Organization Classifications of Haematolymphoid Tumors (WHO-HAEM5). This report illustrates diagnostic challenges and treatment dilemmas that may be encountered, particularly for adolescent and young adults (AYA).

Diagnostic Performance of Six Rapid Antigen Tests for SARS-CoV-2.

Microbiological diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been a challenge. Although real-time reverse transcription PCR (RT-PCR) represents the gold standard method, strategies that allow rapid and simple diagnosis are necessary for the early identification of cases. In this study, we evaluated the diagnostic performance of six different commercial rapid antigen tests (Coronavirus antigen [Ag] rapid test cassette [Healgen Scientific, Houston, TX, USA], COVID-19 Ag FIA [Vircell, SD Biosensor Inc., Gyeonggi-do, Republic of Korea], Clinitest rapid COVID-19 antigen test [Siemens, Healthineers, Erlangen, Germany], SARS-CoV-2 rapid antigen test [SD Biosensor; Roche Diagnostics, Basel, Switzerland], Panbio COVID-19 Ag rapid test device [Abbott, Chicago, IL, USA], and SARS-CoV-2 test [MonLab, Barcelona, Spain]) in 130 nasopharyngeal swab samples tested previously by RT-PCR. The overall sensitivity of the rapid tests ranged from 65% to 79%, and the specificity was 100% for all of them. The sensitivity was higher for those samples with RT-PCR cycle threshold (CT) values below 25 and those from patients presenting within the first week of symptoms. The Siemens test showed the highest sensitivity for patients with high viral loads while the Vircell test performed better than the rest for CT values of ≥25. IMPORTANCE The rapid detection of people infected with SARS-CoV-2 is essential for a correct and effective control of the disease it causes. This process must be sensitive, fast, and simple, and it must be possible to carry out in any type of health center. Rapid antigen tests are the answer to this need. Knowing its ability to detect the virus in different stages of the disease is essential for a correct diagnosis, which is why this study has been carried out to evaluate the sensitivity and specificity of 6 different antigens tests in nasopharyngeal smear samples.

Changes in the gut microbiota and risk of colonization by multidrug-resistant bacteria, infection, and death in critical care patients.

OBJECTIVES: This study aimed to investigate whethehr the diversity and composition of the intestinal microbiota determines the risk of multidrug-resistant organism (MDRO) acquisition, infection, and mortality in patients admitted to a liver intensive care unit (ICU). METHODS: This prospective study included patients admitted to a 12-bed ICU between July and December 2018. Rectal swabs to detect MDRO intestinal colonization were obtained at ICU admission and weekly thereafter during the ICU stay. The 16S rRNA gene sequencing was performed on 138 rectal swabs from 62 patients. We evaluated the potential association between gut microbiota composition and diversity and the risk of MDRO colonization, infection, and hospital mortality. RESULTS: Of the patients studied, 19 of 62 (30.65%) presented with MDRO colonization at admission, 16 (25.81%) were colonized during their stay, and 27 (43.55%) were not colonized; 45 of 62 patients (72.58%) developed an infection, and mortality was 29.03% (18 of 62). Higher bacterial diversity and abundance of Bacillales Family XI incertae sedis and Prevotella families were associated with a lower risk of colonization by MDRO, infection, and death (linear discriminant analysis effect size score >4), whereas the Enterococcaceae family was associated with an increased risk of infection and death (linear discriminant analysis effect size score >4). The LASSO regression and multivariate analysis identified Family XI incertae sedis to be associated with a lower risk of infection (OR: 0.997; 95% CI, 0.996-0.999; p = 0.001) and microbial evenness index to be associated with lower mortality risk (OR: 0.68; 95% CI, 0.49-0.95; p = 0.02). DISCUSSION: Microbial diversity and abundance of certain bacterial taxa could have prognostic value in patients admitted to a critical care unit. Larger perspective studies should address the value of these markers in clinical practice.

Low-Grade Ductal Carcinoma In Situ.

OBJECTIVES: We aimed to determine the interobserver reproducibility in diagnosing low-grade ductal carcinoma in situ (DCIS). We also aimed to compare the interobserver variability using a proposed two-tiered grading system as opposed to the current three-tiered system. METHODS: Three expert breast pathologists and one junior pathologist identified low-grade DCIS from a set of 300 DCIS slides. Months later, participants were asked to grade the 300 cases using the standard three-tiered system. RESULTS: Using the two-tiered system, interobserver agreement among breast pathologists was considered moderate (κ = 0.575). The agreement was similar (κ = 0.532) with the junior pathologist included. Using the three-tiered system, pathologists' agreement was poor (κ = 0.235). CONCLUSIONS: Pathologists' reproducibility on diagnosing low-grade DCIS showed moderate agreement. Experience does not seem to influence reproducibility. Our proposed two-tiered system of low vs nonlow grade, where the intermediate grade is grouped in the nonlow category has shown improved concordance.