Metachronous renal Ewing sarcoma/primitive neuroectodermal tumour in a survivor of Burkitt lymphoma.

We present a case of a 14-year-old girl who was diagnosed with Burkitt lymphoma in 2014. She was managed with chemotherapy and remained in remission for 3 years. On her surveillance imaging in 2017, a left-sided renal neoplastic mass was incidentally discovered. She underwent nephrectomy and pathology of the resected specimen revealed small cell tumour of the kidney with features favouring renal Ewing sarcoma/primitive neuroectodermal tumour. Molecular genetic analysis by fluorescence in situ hybridisation was performed which showed translocation of 22q12, thereby confirming the diagnosis. This is a rare secondary malignancy and an unusual association. This case highlights the importance and diagnostic dilemmas of rare secondary tumours in patients with such haematological malignancies and discusses its possible pathogenetic aspects.