prohemocyte prohaemocyte blast cell hematopoietic precursor cell FBbt:00005062 CL:0000385 HSC An immature hemocyte. It is highly basophilic, with a round to polygonal morphology and measures approximately 4 to 6 micrometers in diameter (Shrestha and Gateff, 1982). The nucleus is rich in nucleoli and is surrounded by a thin band of ribosome-rich cytoplasm (Shrestha and Gateff, 1982). In the larva, these cells can be found in the lymph gland primary lobe, or in circulation (Lanot et al., 2001). fly_anatomy.ontology polygonal cell Pr somatic precursor cell mesodermal derivative