Human pathology
-
Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, has been declared by the World Health Organization as an emerging public health problem of global importance and classified as a pandemic. SARS-CoV-2 infection can result in diverse, multiorgan pathology, the most significant being in the lungs (diffuse alveolar damage in its different phases, microthrombi, bronchopneumonia, necrotizing bronchiolitis, viral pneumonia), heart (lymphocytic myocarditis), kidney (acute tubular injury), central nervous system (microthrombi, ischemic necrosis, acute hemorrhagic infarction, congestion, and vascular edema), lymph nodes (hemophagocytosis and histiocytosis), bone marrow (hemophagocytosis), and vasculature (deep vein thrombosis). An understanding of the spectrum and frequency of histologic findings in COVID-19 is essential for gaining a better understanding of disease pathophysiology and its ongoing impact on public health. To this end, we conducted a systematic meta-analysis of histopathologic observations to date and review the reported findings.
-
A 65-year-old man was hospitalized owing to fever (38.6 °C) and dry cough since 4 days. He visited Wuhan 8 days ago. At admission, nasopharyngeal swab samples were taken, and polymerase chain reaction analysis confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA positivity. ⋯ Microthrombi were seen in the dilated pulmonary capillaries. Immunohistochemistry staining for SARS-CoV-2 N protein was negative. Taken together, the patient died of multiorgan failure although the SARS-CoV-2 infection was cleared already, implicating that for disease worsening, no active SARS-CoV-2 infection is required.
-
Renal cell carcinoma (RCC) with sarcomatoid changes and rhabdoid features has shown poor outcomes. Several immune checkpoint inhibitors including programmed cell death protein 1 (PD-1)/programmed death ligand-1 (PD-L1) inhibitors have been approved for the treatment of RCC. Combination therapy using PD-1/PD-L1 and indoleamine 2,3-dioxygenase 1 (IDO1) inhibitors has also been used to treat various malignancies. ⋯ PD-L1 expression and coexpression of PD-L1 and IDO1 were correlated with a high density of CD3+, CD4+, and CD8+ T cells. There was no significant difference in overall survival among the patients with PD-L1 and/or IDO1 expression, but PD-L1 expression and coexpression were related to poor progression-free survival. Our results suggest that combination therapy using the PD-1/PD-L1 inhibitor and IDO1 inhibitor may be effective for treating sarcomatoid/rhabdoid RCC.
-
Immune checkpoint inhibitors are a major breakthrough in the field of oncology. Targets for approved immune checkpoint inhibitors are cytotoxic T-lymphocytes-associated antigen 4 (CTLA-4) and programmed cell death receptor 1/ programmed cell death ligand 1 (PD-1/PD-L1). Five patients (four males and one female) were treated with immune checkpoint inhibitors for advanced melanoma (stage III). ⋯ Sarcoid-like granulomatous inflammation is an adverse event in patients treated with immune checkpoint therapy such as Ipilimumab and Nivolumab. It can present as enlarged lymph nodes in PET/CT imaging suspicious for malignancy. FNA can serve as a minimally invasive tool to investigate the underlying cause of lymphadenopathy in this subset of patients.
-
Childhood pulmonary Langerhans cell histiocytosis (PLCH) is a rare disease. Its pulmonary histopathology, according to comprehensive clinical-radiological findings and BRAFV600E mutation status, has not yet been thoroughly documented. From the 167 childhood PLCH cases entered in the French National Histiocytosis Registry (1983-2016), we retrieved lung biopsies from a consecutive retrospective series of 17 patients, diagnosed when they were 2 weeks to 16 years old (median, 9.4 years), and report the clinical and histopathological findings herein. ⋯ BRAFV600E mutation was detected in 4 of 12 samples tested, notably in the 3 with unusual features. In conclusion, childhood PLCH mostly shares the common histology features already described in adult PLCH, regardless of age. Because smoking is considered the major trigger in PLCH pathogenesis, the findings based on this series suggest other inducers of bronchiolar LC recruitment, especially in very young patients.