Contributions
Abstract: PB1791
Type: Publication Only
Background
Primary mediastinal large B-cell lymphoma (PMBCL) is derived from a thymic B-cell and commonly presents as a bulky lesion in anterior-superior mediastinum. Extramediastinal lesions is an extremely rare situation and require differential diagnostics with diffuse large B-cell lymphoma (DLBCL).
Aims
To evaluate clinical features and treatment efficacy in patients with PMBCL with extramediastinal lesion.
Methods
From 2007 to 2018 years, 157 patients were diagnosed with PMBCL (according to WHO criteria) in National Research Center for Hematology Ministry of Health, Moscow, Russian Federation. Extramediastinal involvement was detected in 16 patients, 3 of them were at different stages of pregnancy. The median age of patients was 27 (23-69) years.
8/16 patients underwent molecular analysis for determination of gene overexpression JAK2, TRAF1, MAL, PDL1, PDL2. In all 8/8 of cases, overexpression of 2 or more genes was determined, which allowed confirming and in some cases to revise diagnosis in favour of PMBCL.
Results
In 69% of cases, nonlymphoid extramediastinal lesions below diaphragm were verified, which involved internal organs. In 31% of cases, there were multiple involvements of organs. The most frequently were noted involvement of kidney - 4/16 of cases, ovarian - 3/16 of cases, pancreas - 3/16 of cases and bone marrow - 3/16 of cases (confirmed by the molecular study). Gastric involvement was revealed very rarely - 1/16 of cases, an involvement of bones - 1/16 of cases, soft tissues involvement - 1/16 of cases. In 15 from 16 cases, an isolated extramediastinal lesion was combined with involvement of antero-superior mediastinum and only in one from 16 patients was revealed isolated thoracic soft tissues involvement (without involvement of mediastinal structures).
Conclusion
in 15/16 of PMBCL cases extramediastinal lesions were revealed in addition to anterior-superior mediastinum involvement. In 1 of 16 cases, thoracic soft tissue involvement was not accompanied by presence of a tumour in mediastinum. This clinical feature required an additional molecular study that allowed to diagnose primary mediastinal large B-cell lymphoma. Thus, in case of mediastinal tumour and presence of extramediastinal lesions in young patients differential diagnosis between primary mediastinal large B-cell lymphoma and advanced stage diffuse large B-cell lymphoma with extramediastinal lesion should be performed.
Session topic: 21. Aggressive Non-Hodgkin lymphoma - Clinical
Keyword(s): Extranodal lymphoma
Abstract: PB1791
Type: Publication Only
Background
Primary mediastinal large B-cell lymphoma (PMBCL) is derived from a thymic B-cell and commonly presents as a bulky lesion in anterior-superior mediastinum. Extramediastinal lesions is an extremely rare situation and require differential diagnostics with diffuse large B-cell lymphoma (DLBCL).
Aims
To evaluate clinical features and treatment efficacy in patients with PMBCL with extramediastinal lesion.
Methods
From 2007 to 2018 years, 157 patients were diagnosed with PMBCL (according to WHO criteria) in National Research Center for Hematology Ministry of Health, Moscow, Russian Federation. Extramediastinal involvement was detected in 16 patients, 3 of them were at different stages of pregnancy. The median age of patients was 27 (23-69) years.
8/16 patients underwent molecular analysis for determination of gene overexpression JAK2, TRAF1, MAL, PDL1, PDL2. In all 8/8 of cases, overexpression of 2 or more genes was determined, which allowed confirming and in some cases to revise diagnosis in favour of PMBCL.
Results
In 69% of cases, nonlymphoid extramediastinal lesions below diaphragm were verified, which involved internal organs. In 31% of cases, there were multiple involvements of organs. The most frequently were noted involvement of kidney - 4/16 of cases, ovarian - 3/16 of cases, pancreas - 3/16 of cases and bone marrow - 3/16 of cases (confirmed by the molecular study). Gastric involvement was revealed very rarely - 1/16 of cases, an involvement of bones - 1/16 of cases, soft tissues involvement - 1/16 of cases. In 15 from 16 cases, an isolated extramediastinal lesion was combined with involvement of antero-superior mediastinum and only in one from 16 patients was revealed isolated thoracic soft tissues involvement (without involvement of mediastinal structures).
Conclusion
in 15/16 of PMBCL cases extramediastinal lesions were revealed in addition to anterior-superior mediastinum involvement. In 1 of 16 cases, thoracic soft tissue involvement was not accompanied by presence of a tumour in mediastinum. This clinical feature required an additional molecular study that allowed to diagnose primary mediastinal large B-cell lymphoma. Thus, in case of mediastinal tumour and presence of extramediastinal lesions in young patients differential diagnosis between primary mediastinal large B-cell lymphoma and advanced stage diffuse large B-cell lymphoma with extramediastinal lesion should be performed.
Session topic: 21. Aggressive Non-Hodgkin lymphoma - Clinical
Keyword(s): Extranodal lymphoma