B- and T-cell non-Hodgkin's lymphomas with large multilobated cells: morphological, phenotypic and clinical heterogeneity.

Ten cases of non-Hodgkin's lymphomas, mainly composed of large multilobated cells, have been studied. Our results are consistent with the view that they represent a somewhat heterogeneous group of lymphoid tumours displaying different morphological, clinical and immunophenotypic features. In B-cell type the large multilobated cells were histologically characterized by prominent nucleoli and distinctly basophilic cytoplasm whereas in the T-cell type they had indistinct or small nucleoli and ill-defined weakly eosinophilic cytoplasm. These differential features between B- and T-cell type were confirmed by electron microscopy. From a clinical standpoint B-cell type was characterized by a constant involvement of lymphoid tissues (lymph nodes and/or Waldeyer's ring); T-cell type showed, on the contrary, a more frequent involvement of extra-lymphoid sites (mainly bone and subcutaneous tissues). Our study provides some morphological features that may be helpful for a correct differential diagnosis in this heterogeneous group of non-Hodgkin's lymphomas.