Observer variation in the assessment of the histopathologic diagnosis of acute appendicitis

Clinical Proteomics for Solid Organ Tissues

The evaluation of biopsied solid organ tissue has long relied on visual examination using a microscope. Immunohistochemistry is critical in this process, labeling and detecting cell lineage markers and therapeutic targets. However, while the practice of immunohistochemistry has reshaped diagnostic pathology and facilitated improvements in cancer treatment, it has also been subject to pervasive challenges with respect to standardization and reproducibility. Efforts are ongoing to improve immunohistochemistry, but for some applications, the benefit of such initiatives could be impeded by its reliance on monospecific antibody-protein reagents and limited multiplexing capacity. This perspective surveys the relevant challenges facing traditional immunohistochemistry and describes how mass spectrometry, particularly liquid chromatography-tandem mass spectrometry, could help alleviate problems. In particular, targeted mass spectrometry assays could facilitate measurements of individual proteins or analyte panels, using internal standards for more robust quantification and improved interlaboratory reproducibility. Meanwhile, untargeted mass spectrometry, showcased to date clinically in the form of amyloid typing, is inherently multiplexed, facilitating the detection and crude quantification of 100s to 1000s of proteins in a single analysis. Further, data-independent acquisition has yet to be applied in clinical practice, but offers particular strengths that could appeal to clinical users. Finally, we discuss the guidance that is needed to facilitate broader utilization in clinical environments and achieve standardization.

Concordancia entre los hallazgos quirúrgicos e histopatológicos en pacientes con apendicitis aguda en un hospital de tercer nivel de Bogotá, Colombia

Introducción. Los hallazgos quirúrgicos actuales dictan el tratamiento postoperatorio de los pacientes con apendicitis aguda; sin embargo, esto se basa únicamente en el juicio del cirujano durante la apendicectomía. Este estudio tuvo como objetivo determinar la confiabilidad entre evaluadores entre cirujanos y patólogos en un hospital de tercer nivel. Métodos. Estudio transversal retrospectivo realizado entre octubre de 2015 y octubre de 2016 en el Hospital Central Militar de Bogotá. Se incluyeron pacientes que se sometieron a apendicectomía debido a sospecha de apendicitis aguda y tenían histopatología con sus respectivos hallazgos quirúrgicos. Nuestro objetivo fue determinar el acuerdo entre el informe quirúrgico y el de patología. Resultados. Durante el período de estudio, identificamos a 418 pacientes que se sometieron a apendicectomía. Los cirujanos evaluaron 32 (7,77%) apéndices como negativos, 78 (18,93%) como inflamados, 110 (26,7%) como supurativos, 137 (33,25%) gangrenosos y 55 (13,35%) como perforados. La mayor concordancia se observó en pacientes con apendicitis supurativa (82/110; 74.5%). En general, Kappa indicó un acuerdo poco equitativo entre el patólogo y los cirujanos (Kappa = 0.2950, ​​IC 95% 0.2384-035.17, p <0.0001). Conclusión. Hay una pobre concordancia entre los hallazgos quirúrgicos y patológicos en nuestro estudio, similar a los documentos médicos anteriores. Como mensaje, los cirujanos y el patólogo deben revisar la definición de los criterios clínicos e histopatológicos para describir mejor los hallazgos y llegar a un mejor acuerdo.  

Acute appendicitis: modern understanding of pathogenesis, diagnosis, and management

Acute appendicitis is one of the most common abdominal emergencies worldwide. The cause remains poorly understood, with few advances in the past few decades. To obtain a confident preoperative diagnosis is still a challenge, since the possibility of appendicitis must be entertained in any patient presenting with an acute abdomen. Although biomarkers and imaging are valuable adjuncts to history and examination, their limitations mean that clinical assessment is still the mainstay of diagnosis. A clinical classification is used to stratify management based on simple (non-perforated) and complex (gangrenous or perforated) inflammation, although many patients remain with an equivocal diagnosis, which is one of the most challenging dilemmas. An observed divide in disease course suggests that some cases of simple appendicitis might be self-limiting or respond to antibiotics alone, whereas another type often seems to perforate before the patient reaches hospital. Although the mortality rate is low, postoperative complications are common in complex disease. We discuss existing knowledge in pathogenesis, modern diagnosis, and evolving strategies in management that are leading to stratified care for patients.

‘Cure’ as the gold standard for likelihood ratio assessment: theoretical considerations

A gold standard is necessary to assess the validity of homeopathic symptoms. The gold standard is 'cure', but this is difficult to define, and depends on consensus. The likelihood ratio (LR) method will give valid results only if the gold standard is reliable. False positives (patients incorrectly classified as cured) weaken results of LR investigation. Weakening the standard to enlarge the research population will seriously bias the results. The same gold standard should be used in LR assessment of all symptoms.