A rare case of extreme thrombocytosis in a paediatric chronic myeloid leukemia. A rare report

Abstract

We reported a case of chronic myeloid leukaemia (CML) with extreme thrombocytosis. We present an eight-year-old female pupil who presented with a history of upper abdominal discomfort and generalized body weakness of 3 months duration. There was no history of fever, loss of weight, night sweat or difficulty in breathing, but there was associated loss of appetite. There is no history of easy bleeding. Examination revealed mild hepatosplenomegaly. On investigation, she was  found to have extreme thrombocytosis (2,518.000/mm3) and leucocytosis with moderate anaemia, while the peripheral blood film shows leucocytosis, and peripheral film, (Markedly elevated with predominantly myeloid cells with complete spectrum with myelocyte and metamyelocyte peak. Also present were basophilis, esinophilis). She was investigated for both CML, and ET. BCR-ABL was found positive by reverse transcription PCR (RTPCR). She has been commenced on Imatinib. This degree of thrombocytosis is usually seen only in essential thrombocytosis. This review aimed to investigate the available published data on the clinical characteristics of paediatric CML in patients presenting with extreme thrombocytosis. We performed a systematic review of the PubMed, MEDLINE®, ScienceDirect, and Scopus databases for the published literature in the English language during the period 2000-2020 that reported extreme thrombocytosis as an initial presentation in laboratory-confirmed paediatric CML patients. The recognized list of cases and abstracts were evaluated for any additional articles of interest from reference lists and pooled with a case from our institution. In conclusion, every case of CML with extreme thrombocytosis can mimick Essential thrombocythaemia. Essential thrombocythaemia is a close differential diagnosis. Sometimes thrombocythaemia may be the only peripheral blood finding in the chronic phase of CML. Variant BCRABL transcripts may be associated with extreme thrombocytosis in CML. All patients with thrombocythaemia should be investigated for BCRABL translocation.