Expression of programmed death-1 (CD279) in primary cutaneous B-cell lymphomas with correlation to lymphoma entities and biological behaviour

Abstract

A higher number of PD-1-expressing cells was found in indolent PCMZL and PCFCL than in high-malignant DLBCL-LT. The PD-1-positive cells represented not only TFH , but also other activated T cells as a part of the tumour microenvironment. The tumour cells in all investigated types of PCBCL did not show aberrant PD-1 expression.

Expression of programmed death‐1 in cutaneous extranodal natural killer/T‐cell lymphoma and its effect on clinical findings and biological behaviour

“…Mitteldorf et al . investigated the presence of PD‐1‐positive lymphocytes in various entities of primary cutaneous B‐cell lymphoma and correlated these with survival outcomes.…”

“…PD‐1 is also expressed in angioimmunoblastic T‐cell lymphoma (AITL), CD4‐positive small/medium pleomorphic T‐cell lymphoma (SM‐TCL) and B‐cell small lymphocytic lymphoma . Higher PD‐1 levels have been associated with favourable outcomes in nodal follicular lymphoma and primary cutaneous B‐cell lymphoma, but have also been associated with poorer prognoses in many solid tumours …”

Pathologic Diagnosis of Cutaneous Lymphomas

“…The tumor cells themselves were negative for PD-1. 34,104 Moreover, clusters of CD123-positive plasmocytoid dendritic cells have been described, which are found in only a minority of PCFCL and are absent in PCDLBCL-LT. 105 Distinction of PC-FCL from secondary cutaneous infiltrates of nodal follicular lymphoma, which often show expression of bcl-2, requires staging. Secondary cutaneous involvement of mantle cell lymphoma has to be considered in the differential diagnosis.…”

“…109,110 PD-1 expression is significantly lower in PCDLBCL-LT than in PCMZL and PCFCL. 34,104 The tumor cells are predominantly negative for PD-1, but in some cases an expression of PD-1 in the tumor cells can be observed. 34,104 There may be detection of heavy chain rearrangement by PCR.…”

Cutaneous CD4 + small–medium T‐cell Lymphoma

“…frequently in Sézary syndrome and also rarely in mycosis fungoides, as well as in other lymphoma types [32,34], and a complete T FH -cell phenotype has been observed in some cases of Sézary syndrome [35]. In short, cases positive for PD-1 alone do not show sufficient evidence of T FH -cell differentiation, and a T FH -cell phenotype can be observed in well-known cutaneous lymphomas, thus questioning the validity of a "primary cutaneous T FH -cell lymphoma" as a distinct entity.…”