55 yrs old male with lateral LINGUAL radix tumor and head and neck lymphadenopathy ("indurated salivary gland zone") one-sided ipsilaterally.  
Consultation case: original diagnosis NK/T NHL?  
No signs of acute leukaemia or blastemia in PB/flow.  
 
HISTO: "blastoid" and "histiocytoid" diffuse infiltration with reniform ovoid nuclei, eosinophilic cytoplasm. Focal BINARY pattern with clustered large eosinophilic cells (more positive CD1a and Langerin).  
IH FULL: HLA DR+; CD4+; Lysozyme+; CD56+; S100+; CD11c+; LCA+(silpnas); Pax5+ (silpnas); CD1a+/-; Langerin(-/+); Bcl6+; CD3/CD7/CD5/CD2/GranzymB/TIA1/Perforin/CD8/CD30(-); CD20/CD79a(-); CD138/CD38/Mum1(-); Ig kappa/lambda/IgM/IgD/IgA(-); CD68/CD123/CD163/CD14(-); MPO/CD117/CD34/Bcl2/TdT(-); CD23/CD21/CD35(-); EBER/HHV8(-); Ki67 prolif. index high 95%.  
 
Molecs: IgH and IgK clonal; BRAF no mutations in Ex15; NO DEFINITE AML mutations;  
SNP array: COMPLEX HYPERDIPLOID KARYOTYPE: +5, +8, +21 TRISOMIES, 7q, 12q, 9p DELETIONS ir 17q DUPLICATION.  
NOTE: NOT TYPICAL FOR AML/MDS or ALL. Despite HYPERDIPLOIDY, trisomies not typical for ALL. 7q deletion TYPICAL for AML, but, one specific ALL aberration was detected too: CDKN2AB homozygous deletion(9p del). GRAPH IS APPENDED BELOW.  
 
E-microscopy: NO definite Birbecks.  
Bone marrow: reactive follicular hyperplasia, no AML signs (will be appended afterwards).  
 
DIAGNOSTIC VERSION 1 WAS (at first look): Myeloid sarcoma (mono-differenctiation), but S100+ CD68/CD163(-) and B clone, no AML elsewhere, local not-life-threatening process.  
so DIAGNOSTIC VERSION 2 IS: Aggressive histiocytic tumor, probably Langerhans or indetermined cell sarcoma.  
DIAGNOSTIC VERSION 3: Combination of both above.  
 
ThankYou2018.  
 
NOTABENE: our similar published case with dr.Alex: APPENDED BELLOW: Unique composite hematolymphoid tumor consisting of a pro-T lymphoblastic lymphoma and an indeterminate dendritic cell tumor: evidence for divergent common progenitor cell differentiation.  
Buser L, Bihl M, Rufle A, Mickys U, Tavoriene I, Griskevicius L, Tzankov A.  
Pathobiology. 2014;81(4):199-205. doi: 10.1159/000365396. PMID: 25228298