Figure 5: a) MKI of the poorly differentiated neuroblastoma, HE, 20X. Karyorrhexis are seen in poorly differentiated neuroblasitic cells. This case shows low MKI. b) MKI of the undifferentiated neuroblastoma, HE, 60X. Karyorrhexis are seen in undifferentiated neuroblastic cell. This case shows high MKI.