A pediatric case series of catastrophic gastrointestinal complications of posttransplant lymphoproliferative disease with increasing incidence, high association with coronavirus disease 2019, higher mortality, and a plea for early endoscopy to prevent late fatal outcome

BACKGROUND: Posttransplant lymphoproliferative disorder is one of the most severe complications after transplantation, caused by uncontrolled proliferation of Epstein–Barr virus-positive B-cells in the setting of chronic immunosuppression. As one of the biggest transplant centers worldwide, we observed a potential increase in the number of patients with posttransplant lymphoproliferative disorder presenting with gastrointestinal symptoms in 1 year, during the coronavirus disease 2019 pandemic. There is limited information about dysregulation of the immune system following coronavirus disease 2019 infection, which may lead to Epstein–Barr virus reactivation in Epstein–Barr virus-positive B-cells and development of posttransplant lymphoproliferative disorder. Furthermore, there is no consensus in literature on a modality that can help in early diagnosis of posttransplant lymphoproliferative disorder with nonspecific gastrointestinal presentations before late and fatal complications occur. CASE PRESENTATION: Our case series includes five Iranian (Persian) patients, three female (2, 2.5, and 5 years old) and two male (2 and 2.5 years old), who developed gastrointestinal posttransplant lymphoproliferative disorder after liver transplantation. All of our patients were on a similar immunosuppressant regimen and had similar Epstein–Barr virus serologic status (seronegative at time of transplantation but seropositive at time of posttransplant lymphoproliferative disorder diagnosis). Four patients had either a positive coronavirus disease 2019 polymerase chain reaction test or exposure within the family. Although all of our patients presented with nonspecific gastrointestinal symptoms, four patients developed late posttransplant lymphoproliferative disorder complications such as bowel perforation and obstruction. All five patients with gastrointestinal posttransplant lymphoproliferative disorder received chemotherapy, but only two survived and currently are continuing the therapy. In one of the surviving patients, prompt endoscopic investigation resulted in early diagnosis of posttransplant lymphoproliferative disorder and a better outcome. CONCLUSION: Since 80% of our patients had exposure to coronavirus, a potential relationship might be suggested between the two. Furthermore, as we witnessed in one case, urgent endoscopic investigation in immunocompromised patients presenting with gastrointestinal symptoms can improve the clinical outcomes and therefore should be considered for early diagnosis of posttransplant lymphoproliferative disorder. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13256-023-04123-5.