The diagnosis of BPDCN is based on the immunophenotypic diagnostic triad of CD123, CD4, and CD56
, as well as other markers.
However, PNETs express neuroendocrine markers, such as synaptophysin, chromogranin A, and CD56
, and do not react with anti-RCC antibodies.
In order to investigate the expressions of the CD56
and MyoG genes in each group, the tissues were scrutinized through the application of the real-time PCR method.
immunostain and in situ hybridization for Epstein-Barr virus were negative.
However, it is now known to be derived from the recently recognized subtype of dendritic cells named plasmacytoid dendritic cells (PDC) which are characterized by expression of CD4, CD56
, and more PDC-specific markers such as CD123 and CD303.
Accumulated plasma cells in the bone marrow of patients with MM are identified by surface membrane antigens, such as CD38, CD138, CD56
, CD117, and CD33.
Immunohistochemistry showed that Synaptophysin and CD56
were positive in the solid tumor areas and negative in the tubulo-glandular tumor foci (Figure 3); Chromogranin was positive in rare tumor cells, CDX2 was focally positive.
The lymphoma cells are positive for CD3, CD8, CD56
(Figure 1, C and D), and MATK in most cases, but negative for CD4, CD30, and often CD5.
The tumor showed diffuse, strong, cytoplasmic and membranous CD56
, nuclear Fli-1 positivity.
In the immunohistochemical analysis, the tumor cells were positive for LCA, CD3, CD7, CD8, and CD56
, and negative for CD20, CD5, CD4, CD79a, CD10, CD99, and CK.
Flow cytometric immunophenotype (FCI) comprised P1 cells with large forward scatter, expressing CD2/CD7, CD38, CD56
, CD159a, CD161, and human leukocyte antigen-D related but negative for CD34, TDT, CD45, surface CD3, CDd5 CD138, CD19, and CD20, which indicated extranodal NKTCL.