Anitschkow myocytes or cardiac histiocytes in human hearts.

The caterpillar chromatin pattern of the nucleus in longitudinal section and owl-eye appearance in transverse section characterize the Anitschkow cell of Aschoff bodies in rheumatic heart disease. Determining whether it is of muscle origin or cardiac histiocyte has been a source of controversy for many years. In a study of fetal and neonatal hearts from humans, vesicular nuclei often displaying the Anitschkow chromatin pattern were the predominant cell type in the myocardium. Because a similar pattern was also observed in two cell types related to laryngeal cartilage and the neighbouring fibrous tissue in a six week old neonate, it was concluded that the Anitschkow chromatin pattern probably indicates cellular immaturity rather than any specific cell type.