AKT · Haematology/Marrow failure & white cellslow yield

Pancytopenia & aplastic anaemia

Reduction of all three cell lines — marrow failure (aplastic), infiltration, or peripheral destruction

Overview

A reduction in all three blood cell lines (anaemia + neutropenia + thrombocytopenia). The causes group into reduced production (aplastic anaemia, marrow infiltration by leukaemia/myeloma/metastasis/fibrosis, B12/folate deficiency, drugs/chemo/radiation) and increased peripheral destruction/pooling (hypersplenism, severe autoimmune disease). Aplastic anaemia is a hypocellular ('empty') marrow with pancytopenia and no blasts — bone marrow examination is the key step.

Recognise

Combined consequences: anaemia (fatigue/pallor), neutropenia (infections/fever), thrombocytopenia (bruising/bleeding/petechiae)
Aplastic anaemia: pancytopenia with a HYPOCELLULAR marrow and NO abnormal cells/blasts; causes — idiopathic/autoimmune, drugs, viruses, radiation, inherited (Fanconi anaemia)
Clues to the cause: blasts (leukaemia), tear-drop cells/leucoerythroblastic (marrow infiltration/fibrosis), macrocytosis (B12/folate, myelodysplasia), splenomegaly (hypersplenism)

Red flags

Neutropenic sepsis or serious bleeding from severe pancytopenia → emergencies
New pancytopenia → urgent haematology + bone marrow (don't miss acute leukaemia/aplastic anaemia)

Differentials & how to tell them apart

Acute leukaemiablasts on film/marrow — pancytopenia with marrow replacement

Myelodysplastic syndromedysplastic cytopenias in older adults, macrocytosis, risk of AML transformation

Hypersplenism / B12-folate deficiencyperipheral pooling/destruction or megaloblastic — treatable, marrow not 'empty' of cause

Investigations

FBC + blood FILM + reticulocytes; B12/folate; BONE MARROW aspirate and trephine (the key test — cellularity, blasts, infiltration, fibrosis); drug/exposure history; virology; autoimmune screen; cytogenetics for myelodysplasia/leukaemia.

Management

Bone marrow to find the cause + supportive care; aplastic anaemia → immunosuppression/transplant

1Confirm pancytopenia on FBC/film and arrange urgent haematology + BONE MARROW (aspirate and trephine) to find the cause — aplastic (hypocellular, no blasts), infiltrative (blasts/fibrosis), or megaloblastic. Provide supportive care.Gate: Treat neutropenic sepsis and serious bleeding as emergencies; new unexplained pancytopenia must not be dismissed — exclude acute leukaemia.
2Treat the cause (replace B12/folate, treat malignancy, stop the drug); aplastic anaemia → immunosuppression (ATG + ciclosporin) or stem-cell transplant.

Supportive care: transfusion, treat neutropenic sepsis, stop the culprit drug — manage cytopenia consequences while diagnosing

Treat the underlying cause — B12/folate replacement, treat leukaemia/myeloma, manage hypersplenism

Aplastic anaemia: immunosuppression (ATG + ciclosporin) or stem-cell transplant — transplant for younger/severe disease; remove causative drug

Growth factors in selected cases — e.g. G-CSF; specialist-directed

Key points

Pancytopenia (anaemia + neutropenia + thrombocytopenia) → urgent BONE MARROW to find the cause: aplastic (hypocellular, NO blasts), infiltration (leukaemia/myeloma/mets/fibrosis — blasts/tear-drops), or megaloblastic (B12/folate). Supportive care + treat the cause; aplastic → immunosuppression/transplant. Don't miss leukaemia.

Monitor & prognosis

Counts, sepsis/bleeding, marrow response to treatment.

Depends on the cause; severe aplastic anaemia good with transplant/immunosuppression.

Source: BSH aplastic anaemia; cross-ref acute leukaemia