Intravascular large B-cell lymphoma appearance on dual-energy computed tomography: a case report.

BACKGROUND: Intravascular large B-cell lymphoma (IVLBCL) is the proliferation of neoplastic B lymphocytes in the vascular space. Since conventional computed tomography (CT) shows nonspecific findings, differentiation between IVLBCL and other lung diseases, such as diffuse interstitial lung disease, is difficult. CASE PRESENTATION: A 73-year-old man presented with dyspnea and hypoxemia. Laboratory findings showed an increased lactate dehydrogenase level of 1690 U/L (normal: 130-235 U/L) and soluble interleukin-2 receptor level of 1140 U/mL (normal: 157-474U/mL). Dual-energy CT iodine mapping showed a significant symmetrical decrease in iodine distribution in the upper lungs, suggesting an unusual distribution of pulmonary hypoperfusion. Therefore, IVLBCL was suspected. A random skin biopsy confirmed the diagnosis of IVLBCL. Due to the severity of the disease, lung biopsy was averted. After admission to the hospital, high-dose methotrexate was administered for central nervous system involvement, due to findings of suspected intracranial infiltration on a brain magnetic resonance imaging and elevated cell counts on lumbar puncture. Subsequently, oxygen demand improved, and rituximab along with cyclophosphamide, doxorubicin, vincristine, and prednisone was added to the patient's regime. Eventually, oxygen administration was terminated, the patient's general condition improved, and the patient was discharged after 47 days of hospitalization. CONCLUSIONS: Since the diagnosis of IVLBCL depends on whether it is possible to suspect IVLBCL, the finding of decreased iodine perfusion demonstrated on dual-energy CT is considered important information for diagnosis. An immediate diagnosis of IVLBCL is needed to avoid rapid disease progression and introduce early treatment for a favorable prognosis. In this case, unique pulmonary hypoperfusion demonstrated by dual-energy CT promoted early diagnosis of IVLBCL.

Impaired cell-cell communication and axon guidance because of pulmonary hypoperfusion during postnatal alveolar development.

BACKGROUND: Pulmonary hypoperfusion is common in children with congenital heart diseases (CHDs) or pulmonary hypertension (PH) and causes adult pulmonary dysplasia. Systematic reviews have shown that some children with CHDs or PH have mitigated clinical outcomes with COVID-19. Understanding the effects of pulmonary hypoperfusion on postnatal alveolar development may aid in the development of methods to improve the pulmonary function of children with CHDs or PH and improve their care during the COVID-19 pandemic, which is characterized by cytokine storm and persistent inflammation. METHODS AND RESULTS: We created a neonatal pulmonary hypoperfusion model through pulmonary artery banding (PAB) surgery at postnatal day 1 (P1). Alveolar dysplasia was confirmed by gross and histological examination at P21. Transcriptomic analysis of pulmonary tissues at P7(alveolar stage 2) and P14(alveolar stage 4) revealed that the postnatal alveolar development track had been changed due to pulmonary hypoperfusion. Under the condition of pulmonary hypoperfusion, the cell-cell communication and axon guidance, which both determine the final number of alveoli, were lost; instead, there was hyperactive cell cycle activity. The transcriptomic results were further confirmed by the examination of axon guidance and cell cycle markers. Because axon guidance controls inflammation and immune cell activation, the loss of axon guidance may explain the lack of severe COVID-19 cases among children with CHDs or PH accompanied by pulmonary hypoperfusion. CONCLUSIONS: This study suggested that promoting cell-cell communication or supplementation with guidance molecules may treat pulmonary hypoperfusion-induced alveolar dysplasia, and that COVID-19 is less likely to cause a cytokine storm in children with CHD or PH accompanied by pulmonary hypoperfusion.