Lymphomatoid Granulomatosis
Image Description
Lymphomatoid granulomatosis is graded (grades 1-3) based on the proportion of EBV-positive B-cells relative to the background reactive cells.
Grade 1: The lesions have a polymorphous infiltrate in which EBV-positive large atypical cells are absent or rare (fewer than 5 cells/HPF by in-situ hybridization). There is no lymphocytic nuclear atypia and blasts are inconspicuous. Necrosis is absent or focal (one-third of cases).
Grade 2: The infiltrate is polymorphous with greater number of large atypical lymphoid cells (EBV-positive cells number 5-20/HPF). Necrosis is more common.
Grade 3: The morphology resembles large cell lymphoma. EBV-positive large atypical cells are abundant (>50 cells/HPF) and arranged in aggregates or clusters. Necrosis is common.
Grading is critical in the selection of appropriate therapy. Grades 1 and 2 are polyclonal processes and considered low-grade. They are treated with immunomodulating therapies such as interferon-alpha. Grade 3 lesions are monoclonal and high-grade. They behave like diffuse large B-cell lymphoma and require combination of immunotherapy and aggressive chemotherapy. The image shows polymorphous infiltrate of LG.
Grade 1: The lesions have a polymorphous infiltrate in which EBV-positive large atypical cells are absent or rare (fewer than 5 cells/HPF by in-situ hybridization). There is no lymphocytic nuclear atypia and blasts are inconspicuous. Necrosis is absent or focal (one-third of cases).
Grade 2: The infiltrate is polymorphous with greater number of large atypical lymphoid cells (EBV-positive cells number 5-20/HPF). Necrosis is more common.
Grade 3: The morphology resembles large cell lymphoma. EBV-positive large atypical cells are abundant (>50 cells/HPF) and arranged in aggregates or clusters. Necrosis is common.
Grading is critical in the selection of appropriate therapy. Grades 1 and 2 are polyclonal processes and considered low-grade. They are treated with immunomodulating therapies such as interferon-alpha. Grade 3 lesions are monoclonal and high-grade. They behave like diffuse large B-cell lymphoma and require combination of immunotherapy and aggressive chemotherapy. The image shows polymorphous infiltrate of LG.