Introduction
ZNF384 (zinc finger protein 384) re-arrangements are recently
recognized cytogenetic abnormalities that occur in as many as 48% of
mixed-phenotype acute leukaemia (MPAL), B/myeloid and 4% of B-cell
precursor acute lymphoblastic leukaemia (BCP-ALL)1.
Several fusion partners of ZNF384 have been described, the most
common being TCF3, but also EP300, ESWR1, TAF15, CREBBP,
ARID1B, SYNRG and BMP2K 1–3 We report a
challenging case with TCF3-ZNF384 rearrangement that initially
presented as BCP-ALL but showed the emergence of a large myeloid blast
subset following one week of high-dose steroid therapy.