A Case of Mistaken Identity: When All Mimics AML

Area of Science:

• Hematology
• Oncology
• Molecular Biology

Background:

• Acute lymphoblastic leukaemia (B-ALL) with specific gene fusions (SYNRG::ZNF384, P2RY8::CRLF2) presents unique treatment challenges.
• Allogeneic transplantation is a curative option for B-ALL, but relapse or secondary malignancies can occur.

Purpose of the Study:

• To report a rare case of secondary acute myeloid leukaemia (AML M0) in a patient previously treated for B-ALL.
• To discuss the diagnostic complexities and molecular underpinnings of leukaemic transformation.

Main Methods:

• Case report of a 39-year-old male patient.
• Diagnostic evaluation included immunophenotyping and molecular analysis of bone marrow aspirates.
• Treatment involved standard B-ALL protocols, allogeneic transplantation, and subsequent AML therapy.

Main Results:

• The patient achieved complete remission of B-ALL after allogeneic transplantation.
• Twenty-five months post-transplant, the patient developed pancytopenia with bone marrow findings consistent with AML M0.
• The P2RY8::CRLF2 fusion gene was detected in the AML M0 phase, but no clear molecular evidence of a leukaemic lineage switch was identified.

Conclusions:

• This case underscores the diagnostic difficulties in differentiating leukaemic relapse from secondary malignancies.
• The persistence of a B-ALL-associated fusion gene in AML M0 highlights the complex biology of leukaemic evolution.
• Treatment with azacitidine and venetoclax was initiated for the secondary AML M0.