55 yrs female was previously operated due to ovarian mixed poorly dif. (G3) endometrioid- clear cell adenocarcinoma in the endometriosis background.  
At the staging laparotomy multiple peritoneal biopsies and lymph nodes were taken.  
HISTO: Incidentally found medium sized blastic cell infiltration in the sinuses and extranodaly.  
IH (SUM): LCA+; Vimentin+; CD123+; S100+/- (scattered); CD1a/Langerin(-); CD68; CD4(+/+++); CD56+; CD3/MPO/TdT/CD34/CD99(-); Bcl2+; Ki67 ~70%; HLA DR+; Lysozyme+; CD43+.  
BM: reactive changes in biopsy and ANY signs of abberant mono or blastic population is present.  
CLINICALLY: any signs of disease and skin erruptions.  
 
PROPOSAL: Blastic infiltration in the lymph nodes with immunophenotype compatible with AML M5 or blastic plasmacytoid dendritic cell tumor.  
QUESTION: admixture of other (histiocytic) line?  
 
OF NOTE 1: small reactive node near tumorous nodes with pigmented histiocytes in the sinuses display Langerin positivity in the absense CD1a (heavy pigmentation). The question about specificity of Langerin...  
OF NOTE 2: CD123+ (strong) DC2 cells are seen close to tumor mass (CD123+ faint).  
 
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