Contributions
Abstract: PB2079
Type: Publication Only
Background
Mature B-cell lymphomas of the mediastinum include primary mediastinal large B-cell Lymphoma (PMLBCL), classic Hodgkin Lymphoma (CHL), B-cell lymphoma unclassifiable, with features intermediate between diffuse large B-cell lymphoma and CHL (gray zone Lymphoma) and others. PMLBCL and mediastinal CHL, mostly nodular sclerosis (NS) share many clinicopathologic characteristics, however, therapeutic options and responses are quite different.
Aims
We aimed to find distinctive histolologic or immunohistochemical findings to better differentiate PMLBCL and CHL of the mediastinum.
Methods
A total of 32 cases of mediastinal B-cell lymphomas consisting of PMLBCL (N=16), CHL (N=13), and gray zone lymphoma (N=3) were collected from 6 university hospitals from Korea. Immunohistochemistry (IHC) for various cell lineage markers and EBV in situ hybridization were performed to confirm the diagnosis, and additionally, expression of P63, GATA3 and cyclinE was investigated.
Results
Most clinical features were overlapped between PMLBCL and CHL except more frequent disease progression and mortality in PMLBCL (p<0.05). In pathologic review, presence of epithelioid granuloma favored CHL (p=0.078), whereas fine reticulated fibrosis was unique for PMLBCL (p<0.001). By IHC, P63 was predominantly positive in PMLBCL (15/16) than CHL (2/11) with the highest diagnostic power (p<0.001). GATA3 was expressed in the majority of CHL (9/12) compared with PMLBCL (0/16) (p<0.001). Expression of cyclinE was rarely found in a minor population of PMLBCL.
Conclusion
Expression of P63 in the tumor cells, even focal, is the most helpful feature to distinguish PMLBCL from mediastinal CHL. Additional diagnostic markers include GATA3 in CHL and reticular fibrosis in PMLBCL
Session topic: 18. Non-Hodgkin & Hodgkin lymphoma - Biology
Keyword(s): Thymus, Pathology, lymphoma, Hodgkin's Lymphoma
Abstract: PB2079
Type: Publication Only
Background
Mature B-cell lymphomas of the mediastinum include primary mediastinal large B-cell Lymphoma (PMLBCL), classic Hodgkin Lymphoma (CHL), B-cell lymphoma unclassifiable, with features intermediate between diffuse large B-cell lymphoma and CHL (gray zone Lymphoma) and others. PMLBCL and mediastinal CHL, mostly nodular sclerosis (NS) share many clinicopathologic characteristics, however, therapeutic options and responses are quite different.
Aims
We aimed to find distinctive histolologic or immunohistochemical findings to better differentiate PMLBCL and CHL of the mediastinum.
Methods
A total of 32 cases of mediastinal B-cell lymphomas consisting of PMLBCL (N=16), CHL (N=13), and gray zone lymphoma (N=3) were collected from 6 university hospitals from Korea. Immunohistochemistry (IHC) for various cell lineage markers and EBV in situ hybridization were performed to confirm the diagnosis, and additionally, expression of P63, GATA3 and cyclinE was investigated.
Results
Most clinical features were overlapped between PMLBCL and CHL except more frequent disease progression and mortality in PMLBCL (p<0.05). In pathologic review, presence of epithelioid granuloma favored CHL (p=0.078), whereas fine reticulated fibrosis was unique for PMLBCL (p<0.001). By IHC, P63 was predominantly positive in PMLBCL (15/16) than CHL (2/11) with the highest diagnostic power (p<0.001). GATA3 was expressed in the majority of CHL (9/12) compared with PMLBCL (0/16) (p<0.001). Expression of cyclinE was rarely found in a minor population of PMLBCL.
Conclusion
Expression of P63 in the tumor cells, even focal, is the most helpful feature to distinguish PMLBCL from mediastinal CHL. Additional diagnostic markers include GATA3 in CHL and reticular fibrosis in PMLBCL
Session topic: 18. Non-Hodgkin & Hodgkin lymphoma - Biology
Keyword(s): Thymus, Pathology, lymphoma, Hodgkin's Lymphoma