Emperipolesis

EMPERIPOLESIS 

● presence of an intact cell within the cytoplasm of another cell. 
● defined by as, "the active penetration of one cell by another which remains intact". 
● It differs from phagocytosis :- because the engulfed cell exists within another cell and remains viable, and can exit without any physiological and morphological changes in them. 
● Etiopathogenesis of emperipolesis is uncertain. 
● seen in 
1) hematolymphoid disorders e.g. myeloproliferative disorders, nonHodgkin's lymphoma, idiopathic myelofibrosis, myelodysplastic syndrome (MDS) 

2) Rosai-Dorfman disease. 

3) Autoimmune hepatitis.

4) megakaryocytic emperipolesis is seen in ---- MDS.
5) lymphocytes within Astrocytes (emperipolesis) in multiple sclerosis plaques and brain tumors.

6) Lymphocytic- emperipolesis----CHRONIC LYMPHOCYTIC LEUKEMIA.