Describe morphology, protect specimens, and avoid premature classification

Before interpreting a flagged result, complete the preanalytic checks defined by the local procedure: match patient and specimen identification; confirm specimen type, collection time, transport or storage history, and acceptance status; inspect for clot, hemolysis, inadequate volume, or delay; verify analyzer quality-control status and flag context; and assess smear preparation and stain quality. Correlate with prior results when that comparison is available. A compromised specimen does not erase an urgent concern; it changes the documented suitability and routing decision.

Describe cell size, chromatin, nucleoli, cytoplasm, granules, and any Auer rods rather than forcing a lineage call. An abnormal promyelocyte-rich field with dense granules, irregular folded or bilobed nuclei, and multiple or bundled Auer rods is an urgent concern for acute promyelocytic leukemia, or APL; less-granular forms may also occur. Morphology alone does not confirm APL. Suspected APL calls for urgent local escalation, coagulation assessment, and rapid testing for PML::RARA, the defining fusion of APL, through the appropriate laboratory pathway.

Allocate before fixation or specimen exhaustion according to the local volume, stability, transport, and routing rules. Preparing a slide preserves morphology but does not retain viable cells. Before allocating, check specimen type, anticoagulant, available volume, stability window, viability when required, and transport conditions for the receiving method. Flow cytometry and conventional cytogenetics generally need suitable viable, unfixed cells; the specimen, medium, timing, and transport requirements are method- and laboratory-specific. FISH and molecular testing may have different validated specimen requirements. Do not promise every study from every tube: document what was sent, what remains, suitability limitations, and any receiving-laboratory instructions. FISH or molecular testing complements rather than replaces conventional karyotyping in the initial workup.

Recognition, preanalytic disposition, and communication are the bench scope here. A manual blast percentage, flow panel selection, specimen-stability limits, critical-result thresholds, an AML or APL diagnosis, and treatment decisions require validated local procedures and the integrated diagnostic process. WHO fifth edition and International Consensus Classification, or ICC, use integrated morphology and genetics and differ in some classification conventions; no detailed WHO/ICC diagnostic threshold is supplied here. Use the named classification system in the final integrated interpretation. Do not independently classify acute leukemia from a morphology field or a single ancillary result.