A Curious Case of Atypical Acute Promyelocytic Leukaemia in a 4-Year Boy

A 4-year boy presented with a history of fever, bruises, frequent transfusions, and left eye proptosis for 1 month. His baseline bone marrow biopsy and immunophenotyping by flow cytometry were consistent with acute promyelocytic leukaemia (APL), but bone marrow cytogenetics were consistent with variant translocation, a non-classical translocation involving chromosome 15 but with different fusion partners than t(15; 17). He initially did not respond to the high-risk APL induction protocol. Later, he was given a high-risk AML induction protocol, to which he responded, but due to financial constraints, the family could not opt for a curative haplo-identical bone marrow transplant, and eventually, the child died. This is the first case of APL with such a variant translocation documented in Pakistan. It is important to document such cases to gather their data, discuss the effectiveness of attempted treatments, and analyse subsequent responses.