[Immunoperoxidase study of 18 malignant lymphoblastic lymphomas (LMLbl) in children].

Eighteen cases of malignant lymphoblastic lymphomas in children were studied by immunoperoxidase technique on frozen tissue sections and/or cytological samples. Different monoclonal or polyclonal antibodies were used: OKT8, OKT11, OKB2, OKIal, anti immunoglobulins (mu, kappa, lambda chains). The results were compared with those of classical histology: three histologically unclassified malignant lymphoblastic lymphomas were linked to a Bor T line (one pre-B lymphoma and two T lymphomas). One diagnosis of T lymphoma could not be confirmed by immunoperoxidase technique. The technique did not reveal any surface immunoglobulins in two cases of malignant lymphomas of Burkitt type. Every one of the remaining 12 cases gave concordant results between morphological and immunological studies. In 12 cases it was possible to compare the results of immunological typing on tissue sections and cell suspension. The results were concordant in 11/12 cases. An advantage of this immunochemical technique on frozen sections and/or cytological samples is that it gives good visualisation of the cells and their reactivity with the antibodies.