Article

Virchows Archiv B

, Volume 35, Issue 1, pp 283-290

First online:

Emperipolesis of hematopoietic cells in myelocytic leukemia

Electron microscopic and phase contrast microscopic studies
  • Mikihiro ShamotoAffiliated withDepartment of Pathology, Fujita-Gakuen University School of Medicine

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Summary

In a case of blast crisis of chronic myelocytic leukemia, the blast cells contained several kinds of normal hematopoietic cells. The peroxidase reaction was strongly positive in the neutrophilic granules of the engulfed neutrophils. These engulfed cells appeared to be normal and the limiting membranes of the engulfing cells seemed to be intact. We speculated therefore that this phenomenon might be emperipolesis. In a case of chronic myelocytic leukemia and a case of acute myelocytic leukemia, some megakaryoblasts showed the same phenomenon. These megakaryoblasts did not phagocytize latex particles. The limiting membranes of the engulfing megakaryoblasts were stained with ruthenium red but those of the engulfed hematopoietic cells were not stained. By phase contrast microscopy, the engulfed cells were actively moving inside the megakaryoblasts and it was observed that the engulfed cells were actually living within the engulfing cells. These results demonstrated that this phenomenon was emperipolesis. Observations with an electron microscope and phase contrast microscope are indispensable for distinguishing emperipolesis from phagocytosis.

Key words

Emperipolesis Hematopoietic cell Myelocytic leukemia Blast cell Megakaryoblast