Primary Hematopoietic and Lymphoid Tissue ›› Bone Marrow ›› Normal

Immature B-cell (Later Hematogone)*

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Microscopic Features:
  • 2-4x larger than a mature RBC (variable size given their variable stage of maturation)
  • High nuclear to cytoplasmic ratio
  • Round Nucleus with immature chromatin (not clumped)
  • Nucleoli are present (specially on less mature stages) but less prominent than blasts
  • Cytoplasm is scant, light blue and lacks granules
  • Usually it is morphologically indistinguishable from a Lymphoblast
Normal % blood-PB, marrow-BM, lymphoid tissue-LN:
  • PB: None
  • BM: Scattered
  • LN: None
May Resemble: Differential Diagnoses:

If in blood or increased numbers in bone marrow:
Maybe increased in newborns (not to be confused with acute leukemia)
May be seen in recovering bone marrows (e.g. post-treatment)
Acute Leukemia

Classic Immunophenotype:
  • CD19+
  • CD10+
  • CD20+/-
  • CD34-
  • TdT-
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  • These are immature B-cells that are usually morphologically indistinguishable from lymphoblasts. Hematogones are a immunophenotypically diverse group of immature B-cells (Earlier forms have less mature markers such as CD34 and TdT while the more mature forms lack CD34 and TdT and partially express CD20) See the B-cell Maturation Diagram for more details

Content Editors/Website Administrators:
Hooman H. Rashidi, MD; John C. Nguyen, MD