Fig. 1From: 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 outcomeA Case 4 colonoscopy picture. B Case 3 endoscopy picture. C Lymph node biopsy of case 2 shows diffuse infiltration of lymphoma cells which are all positive for CD20. D Small intestine biopsy of case 2 shows diffuse infiltration of atypical lymphocytes which are all CD20 positiveBack to article page