Guided example: stage the evidence

Stage one in case 1 shows bruising, an immature-cell flag, ANC 0.8 × 10^9/L, CBC-confirmed anemia and thrombocytopenia, and a smear-confirmed blast population (2 of 100 leukocytes counted). The preferred laboratory action is to preserve the remaining specimen immediately in parallel with the CBC and smear, communicate the finding to the qualified reviewer and clinician through the local urgent pathway, document that communication separately, and only then coordinate time-sensitive flow testing under accepted-specimen rules after contacting the receiving flow laboratory. The first result supports concern, not a final oncologic diagnosis.

Stage two adds a small abnormal precursor population by flow. Before that finding carries weight, the specimen must meet suitability and viability thresholds, acquisition must reach the local target-event count, and gating must isolate the population from debris and mature cells. A qualified second reviewer then compares the candidate cell against stated blast criteria — high nuclear-to-cytoplasmic ratio, fine open chromatin, one or two visible nucleoli, and scant agranular basophilic cytoplasm — against a look-alike such as a reactive lymphocyte, which instead shows condensed chromatin, no visible nucleoli, and more abundant cytoplasm. This increases the need for integrated evaluation, but it remains conditional on specimen quality, event count, gating, morphology, and the qualified diagnostic review. Report the observed laboratory finding using approved preliminary language rather than assigning a WHO or ICC category.

Stage three shifts to a newborn dried blood spot with pattern FS. Before the pattern can be trusted, remember that HPLC retention time and IEF band position can each be shared by more than one variant (co-elution or co-migration), so the screen result needs confirmation by a complementary separation method, with molecular testing when needed. Because no or minimal HbA appears, the beta-chain basis points toward HbSS, HbS/beta-zero thalassemia, or, less commonly, HbS with hereditary persistence of fetal hemoglobin (HPFH) — not a single confirmed genotype. Release the verified observation and the required follow-up pathway, not a genotype or family counseling message.