Table 2.
MIST 1 Immunohistochemistry characteristics
| # cases | CD38 or CD138 | MIST1 characteristics in non-neoplastic cells | MIST1 characteristics in neoplastic cells | |
|---|---|---|---|---|
| PCN | 21 | Positive in 19 cases (2 not done) | negative in lymphocytes | All plasma cells with strong nuclear reactivity |
| PBL | 10 | Positive in 9 cases, negative in 1 case | negative in lymphocytes | Strong nuclear reactivity (3/10), variable nuclear reactivity (1/10), weak nuclear reactivity (6/10) |
| MZL | 10 | Positive in subset | negative in lymphocytes | Strong nuclear reactivity in plasma cells and lymphocytes (5/9), strong nuclear reactivity in plasma cells (6/9) |
| LPL | 7 | Positive in subset | negative in lymphocytes | Strong nuclear reactivity in plasma cells and lymphocytes |
| FL | 8 | N/A | negative in lymphocytes, positive in scattered single plasma cells | Negative in the majority of cells |
| CLL/SLL | 9 | N/A | Nuclear reactivity in scattered single plasma cells | Negative in the majority of cells |
| MCL | 8 | N/A | Nuclear reactivity in scattered single plasma cells | Negative in the majority of cells, |
| Normal | 10 | N/A | Nuclear reactivity in scattered single plasma cells | Negative in the majority of cells |
| DLBCL | 1 | N/A | Nuclear reactivity in scattered single plasma cells | Negative in the majority of cells |
| PTLD | 1 | Positive in anaplastic portion of PTLD | Negative in lymphocytes | Negative with sparse cells positive in monomorphic B cell portion of PTLD, dim positive in anaplastic portion of PTLD |
| CD138 neg PB | 1 | negative | Negative in lymphocytes | Weak nuclear reactivity in plasma cells |
plasma cell neoplasm (PCN), plasmablastic lymphoma (PB), marginal zone lymphoma (MZL), lymphoplasmacytic lymphoma (LPL), follicular lymphoma (FL), chronic lymphocytic lymphoma/small lymphocytic lymphoma (CLL/SLL), mantle cell lymphoma (MCL), Diffuse large B cell lymphoma (DLBCL), a CD138 negative plasmablastic lymphoma (CD138 neg PB), and a posttransplant lymphoproliferative disorder with plasmablastic differentiation (PTLD).