[Large-cell anaplastic lymphomas: a genetic and immunophenotypic study].

PURPOSE

To characterize from a genetic point of view a group of non-Hodgkin's anaplastic large-cell lymphomas (ALCL) by Southern blot and PCR methods with different probes (molecular study) and with direct or post 24-78 hours cultures with GTC banding techniques (cytogenetic). To correlate the results to the immunophenotype performed with a complete panel of monoclonal antibodies (MoAb) according to avidin-biotine and alkaline phosphatase (APAAP) methods.

MATERIAL AND METHODS

Sixty cases of ALCL were reviewed and only 19 selected (with frozen or fresh material) because a complete immunohistologic and genotypic correlation had been done. According to CD15 expression two groups were considered, CD15+ (the so-called Hodgkin's related or Hodgkin's like) and CD15- or classical type.

RESULTS

Only 26.5% of cases showed immuno -genotypic correlation. Immunohistochemistry is an accurate method for activation, proliferation and B-cell nature, but T-cell cases were not stained because T-cell paraffin markers are not completely specific. CD15 group had only 30% rearranged cases with scarce cytogenetic abnormalities, as it occurs in Hodgkin's disease (HD). ALCL classical type showed 66% rearranged cases, and one of the T-cell cases showed an incomplete t (2:5) translocation or polyploid cell lines.

CONCLUSIONS

Both groups have different genetic and immunophenotypic behaviour which resembles HD or NHL. CD15 positive cases or ALCL HD-related constitute a borderline entity which has to be recognized because of the different therapy and clinical behaviour.