Stromal cells in primary myelofibrosis: ultrastructural observations

The bone marrows of five patients with primary myelofibrosis at different stages of the disease have been studied. In the myelofibrotic bone marrow, associated with "reticulum cells", two other cell types have been identified, namely fibroblast-like and myofibroblast-like reticulum cells, as well as a spectrum of transitional forms. Our findings suggest that reticulum cells may represent a reserve stromal cell pool (i.e. primitive reticulum cells) able to modulate themselves and to transform differently according to functional requirements. Some suggestions regarding the functional significance of fibroblast-like and myofibroblast-like reticulum cells in primary myelofibrosis are suggested.