GELA category | Histology | Clinical significance | Comments |
Complete histological response (CR) | Total disappearance of the lymphoid infiltrate with only scattered small lymphocytes and plasma cells. Regressive stromal changes with fibrosis and separation of glands can be seen. | Complete remission | Identification of CR may be subject to sampling ‘artefact’ and the designation of complete regression needs sustained absence of histological disease in the context of remission as assessed by all other means. No need for additional treatment. |
Probable minimal residual disease (pMRD) | Small lymphoid aggregates present, usually at the base of the lamina propria. Associated stromal regressive changes are usually present. | Complete remission | The significance of the lymphoid aggregates is impossible to determine by morphology or immunocytochemistry, but it has been established that these nodules frequently, but not always, harbour cells with the same clonal gene rearrangement as the original lymphoma cells, consistent with the presence of a small number of residual neoplastic cells. However, no adverse prognostic significance has been demonstrated associated with this histology which is detected in early follow-up biopsies after Helicobacter pylori eradication of most cases undergoing subsequent complete remission. No need for additional treatment. |
Responding residual disease (rRD) | Overt residual lymphoma with a nodular or diffuse infiltrate of neoplastic B-cells but with clear evidence of regressive stromal changes characterised by fine fibrosis and an ‘empty lamina propria’. | Partial remission | Comparison with the diagnostic biopsy is helpful in this context. These features are considered to indicate a partial and ongoing response. In the absence of unfavourable endoscopic results or a clinical appearances of progression, a decision about additional treatment can be postponed until after the following endoscopic assessment. Management should be individually tailored. |
No change (NC) | Persistence of overt lymphoma identical to that seen at diagnosis with no morphological features to suggest response to treatment (such as stromal fibrosis). | Stable disease or progressive disease | In the case of persisting macroscopic lesions or evidence of dissemination of the disease, oncological treatment should be proposed. If only microscopic infiltration is present, oncological treatment can be postponed up to 24 months after achievement of Helicobacter pylori eradication, after which management should be individually tailored. |
GELA, Groupe d'Etude des Lymphomes de l'Adult; MALT, mucosa-associated lymphoid tissue.