|
| Genetic alteration | Frequency |
|
| BCL6 gene | |
| (1) Rearrangement | Rare in PTLD |
| (2) SHM | 50% of PTLD |
| c-Myc gene rearrangement | 100% PT-BL |
| BCL2 gene | |
| (1) Rearrangement | Very rare in PTLD |
| (2) Amplification | A proportion of PTLD |
| P53 gene mutation/deletion | Small proportion of mPTLD |
| Translocations involving IG genes | A small proportion of PTLD. Rarely in florid follicular hyperplasia in posttransplant setting |
| PAX5 gene | |
| (1) Rearrangement | Very rare in PT-DLBCL |
| (2) SHM | Very rare in PT-DLBCL |
| (3) Amplification | A proportion of PTLD |
| Chromosomal gains | |
| (1) 3q27, 7q, 8q24, 12q, 12p, 18q21, 21q | |
| (2) 5p and 11p | PT-DLBCL = iDLBCL |
| (3) 6q25.3 | Recurrent in PT-BL |
| (4) 1q, 11q, and of chromosome 7 | PT-DLBCL |
| Chromosomal loss | |
| (1) 1p, 6q, 9p, and 17p13 | Common to PTLD and lymphomas immune competent patients |
| (2) 4q, 17q, and Xp | In PTLD but not common in other lymphomas |
| (3) 12p, 4p, 4q, 12q, 17p, and 18q | Frequent in PT-DLBCL |
| (4) 11q25 | Recurrent in PT-BL |
| (5) 2p16.1 (FRA2E) | 30% of PT-DLBCL (both in EBV positive and negative cases) |
| (6) 17p | PT-DLBCL |
| Aberrant hypermethylation of | |
| (1) MGMT | 75% pPTLD and 93% mPTLD. |
| (2) DAP-kinase | 75% mPTLD |
| (3) TP73 | 20% mPTLD |
| (4) SHP1 | ~77% PT-DLBCLs, 75% pPTLDs, 66% PT-BLs |
| (5) CDKN2A | A small proportion of mPTLD |
|
