Pulmonary veno-occlusive disease in a pediatric hematopoietic stem cell transplant patient: a cautionary tale

Pulmonary Veno-occlusive Disease that Developed Following Hematopoietic Stem Cell Transplantation for Acute Myeloid Leukemia

We herein report a case of pulmonary veno-occlusive disease (PVOD) induced by allo-hematopoietic stem cell transplantation (HSCT) in a 48-year-old man who was diagnosed with acute myeloid leukemia. Five months after transplantation, he developed dyspnea and was diagnosed with pulmonary hypertension based on right heart catheterization. Although he received treatment with pulmonary vasodilators, diuretics, and corticosteroids, his pulmonary artery pressure did not decrease, and his pulmonary edema worsened. Based on the clinical course, hypoxemia, diffusion impairment, and computed tomography findings, the patient was diagnosed with HSCT-related PVOD. Critical attention should be paid to dyspnea after HSCT for the early diagnosis of PVOD.

Pulmonary Manifestations and Vascular Changes in Pediatric Transplantation-Associated Thrombotic Microangiopathy

Although transplant-associated thrombotic microangiopathy (TA-TMA) commonly complicates pediatric hematopoietic cellular therapy (HCT), pulmonary manifestations and histology of TA-TMA (pTA-TMA) are rarely reported, with scant data available on timing, risk factors, pathogenesis, and outcomes. Pulmonary hypertension (PH) and diffuse alveolar hemorrhage (DAH) are recognized manifestations of pTA-TMA. The objective of this study was to characterize the pathologic findings, outcomes, and coincident diagnoses preceding biopsy-proven pTA-TMA. In Institutional Review Board- approved retrospective studies, available lung tissue was reviewed at 2 institutions between January 2016 and August 2021 to include those with pulmonary vascular pathology. Histologic features of pTA-TMA were present in 10 children with prior respiratory decline after an allogeneic HCT (allo-HCT; n = 9) or autologous HCT (n = 1). Pathologic lesions included muscular medialization, microthrombi, and red cell fragments, in addition to perivasculitis and intimal arteritis. Parenchymal findings included diffuse alveolar damage, organizing pneumonia, and plasmocytic infiltrates. Six children were clinically diagnosed with TA-TMA, and all were treated with eculizumab, at a median of 2.5 days after clinical diagnosis (range, 0 to 11 days). Four were identified postmortem. Coincident pulmonary infection was confirmed in 8 of the 10 patients. Five allo-HCT recipients (56%) experienced graft-versus-host disease (GVHD; 4 acute, 1 chronic) prior to the onset of respiratory symptoms. Two patients (20%) had clinically recognized DAH, although 9 (90%) had evidence of DAH on histology. Although all 10 patients underwent echocardiography at the time of symptom onset and 9 had serial echocardiograms, only 2 patients had PH detected. Treatments varied and included sildenafil (n = 3), steroids (n = 1), and eculizumab (n = 6). One patient was alive at the time of this report; the remaining 9 died, at a median of 52 days after onset of respiratory symptoms (range 4 to 440 days) and a median of 126 days post-HCT (range, 13 to 947 days). pTA-TMA is a heterogeneous histologic disease characterized by arteriolar inflammation, microthrombi, and often DAH. pTA-TMA presented with respiratory decline with systemic TA-TMA in all patients. Clinicians should maintain a high degree of suspicion for DAH in patients with TA-TMA and pulmonary symptoms. Coincident rates of GVHD and pulmonary infections were high, whereas the rate of PH identified by echocardiography was 20%. Outcomes were poor despite early use of eculizumab and other therapies. Our data merit consideration of pTA-TMA in patients with acute respiratory decline in the setting of systemic TA-TMA, GVHD, and infection. Investigation of additional therapies for pTA-TMA is needed as well. © 2022 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Pulmonary veno-occlusive disease in childhood-a rare disease not to be missed

Pulmonary veno-occlusive disease (PVOD) is a rare disease leading to pulmonary hypertension and potentially death related to right heart failure and/or respiratory insufficiency. Clinical symptoms are heterogenous and nonspecific: fatigue, decreased exercise tolerance, shortness of breath on exertion, cough, dizziness, chest pain with exercise, palpitations, syncope, as well as nonspecific symptoms such as headache, poor appetite, pallor or perioral cyanosis. Mutations in the EIF2AK4 (eukaryotic translation initiation factor 2-alpha kinase 4) have been recently described, other risk factors include exposure to organic solvent and trichloroethylene, tobacco exposure and chemotherapy. Echocardiography helps to estimate right ventricular systemic pressure, but further diagnostic workup includes cardiac catheterization to confirm pulmonary hypertension and increased pulmonary vascular resistance. High-resolution computed tomography reveals typical findings: centrilobular ground-glass nodules or opacities, septal lines, thickened interlobular septa, mosaic perfusion, and lymphadenopathy. Histology remains the gold standard, but carries risks for the patient. Proper workup is essential in order to avoid incorrect diagnosis. Pulmonary hypertension targeted treatment has been used in patients with PVOD, however, experience is limited, vasodilatory effects on pulmonary vasculature may lead to deterioration of the patients and should be used with great caution. Lung transplantation is currently the only valid treatment option for patients with PVOD. With prolonged waiting time and progression of the disease mechanical support could be considered.

Pediatric oncologic emergencies: Clinical and imaging review for pediatricians

Children with cancer are at increased risk of life-threatening emergencies, either from the cancer itself or related to the cancer treatment. These conditions need to be assessed and treated as early as possible to minimize morbidity and mortality. Cardiothoracic emergencies encompass a variety of pathologies, including pericardial effusion and cardiac tamponade, massive hemoptysis, superior vena cava syndrome, pulmonary embolism, and pneumonia. Abdominal emergencies include bowel obstruction, intussusception, perforation, tumor rupture, intestinal graft-versus-host disease, acute pancreatitis, neutropenic colitis, and obstructive uropathy. Radiology plays a vital role in the diagnosis of these emergencies. We here review the clinical features and imaging in pediatric patients with oncologic emergencies, including a review of recently published studies. Key radiological images are presented to highlight the radiological approach to diagnosis. Pediatricians, pediatric surgeons, and pediatric radiologists need to work together to arrive at the correct diagnosis and to ensure prompt and appropriate treatment strategies.