Cup-like blasts in acute myeloid leukemia.

Area of Science:

• Hematology
• Oncology
• Cytopathology

Background:

• Acute myeloid leukemia (AML) is a heterogeneous clonal hematopoietic stem cell malignancy.
• Morphological variants of AML blasts can influence diagnosis and prognosis.
• Cup-like blasts (CLB) represent a rare cytological pattern in AML.

Purpose of the Study:

• To report a case of AML with normal karyotype and cup-like blasts (CLB).
• To illustrate the characteristic morphology of CLBs using Pappenheim staining and transmission electron microscopy (TEM).
• To explore the association between CLB morphology and specific molecular aberrations in AML.

Main Methods:

• Case report of an AML patient.
• Morphological analysis of peripheral blood smears stained with Pappenheim.
• Transmission electron microscopy (TEM) for ultrastructural examination of blasts.
• Immunophenotyping for CD34 expression.
• Correlation with molecular genetic testing (NPM1 and FLT3-ITD).

Main Results:

• The patient presented with AML and a normal karyotype.
• Pappenheim-stained smears revealed characteristic cup-like morphology of the blasts.
• TEM confirmed an invaginated nuclear pocket compressing chromatin in CLBs.
• Cup-like blasts typically showed negative CD34 expression.
• A close relationship was observed between CLB-AML and NPM1 and/or FLT3-ITD mutations.

Conclusions:

• Cup-like blasts (CLB) are a distinct cytological feature in a subset of AML patients with normal karyotype.
• The characteristic ultrastructure of CLBs is visualized by TEM.
• CLB morphology is associated with specific molecular alterations (NPM1/FLT3-ITD), potentially impacting AML classification and treatment strategies.