Abstract
Congenital leukaemia (CL) is an exceptionally uncommon hematologic malignancy originating intrauterine and is typically associated with an unfavourable prognosis. The present case is a seven-day-old Malay baby girl who presented with mild fever and hepatosplenomegaly. She was initially treated as neonatal sepsis however subsequent investigations with bone marrow, trephine biopsy and immunophenotyping were consistent with B acute lymphoblastic leukaemia. The peripheral blood smear showed the presence of 90% blast cells. Cytogenetically, she harboured an unusual complex karyotype, 46,XX,der(5) t(5;15)(p15;q15),del(7)(q33q35)/47,idem,+2.ish t(5;15)(wcp15+)+22(wcp22+). This rare case with extremely atypical cytogenetic findings is being brought to light since the patient responded favourably to the standard chemotherapy Interfant 06 protocol, during which she obtained many episodes of remission, and she still survives after three years of treatment. Despite that, she carries del(7), which is normally associated with adverse outcomes in myeloid disorders, but not in lymphoid disorders; the existence of t(5;15)(p15;q15) could be the element that contributes to her fortunate outcome. Although trisomy 22 is identified as a clonal abnormality, its significance in her case and lymphoid disorders remains unknown and requires further investigation.