Transplant-associated thrombotic microangiopathy (TA-TMA) is an under-recognized yet potentially devastating complication of hematopoietic stem cell transplantation which had increased awareness in recent years. This report summarizes territory-wide experience of paediatric TA-TMA in the Hong Kong Children’s Hospital from 1 April 2019 to 31 March 2021. Total six patients were identified among 73 transplants performed. Median duration of onset was 2.5 months post-HSCT. Three patients died while all 3 survivors suffered from stage 2 to 5 chronic kidney disease despite administration of eculizumab. To conclude, recognition and diagnosis of TA-TMA is challenging. Clinical utility of complement blockage with eculizumab is limited.

Primitive myxoid mesenchymal tumour of infancy (PMMTI) a rare and aggressive soft tissue tumour driven by alteration in the BCOR gene. Localised disease may be cured by surgical resection but metastatic disease often displays suboptimal chemotherapy response. Here we report the course of a patient with widely metastatic PMMTI, where durable disease control was achieved with the combination of apatinib, a VEGFR inhibitor, and chemotherapy with irinotecan/temozolomide.