[Malignant lymphomas of soft tissues]

Among annually 1000 consultation cases of soft tissue tumors, minimally 1.2% to maximally 2% malignant lymphomas could be identified, which presented as (primary) soft tissues tumor. Thus malignant lymphoma as soft tissue tumor is rare, however, it has to be considered in differential diagnosis not only of cellular round cell sarcoma, but also with undifferentiated carcinomas (large cell Ki-1 lymphomas) and various myxoid spindle cell sarcomas (sarcomatoid lymphoma). Decisive in differential diagnosis were decorations with pan-leucocyte antibody, as well as, B- and T-cell markers. All cases turned out to be non-Hodgkin lymphomas, the majority of B-cell type, with large cells which qualified as centroblasts (according to Kiel classification). Similar findings, predominance of B-cell non-Hodgkin lymphomas with large cells, were reported in the few series published of malignant lymphomas as soft tissue tumors. Remarkable were relatively good prognosis with "highly malignant" morphology and preference for involvement of soft tissue even after dissemination. Future studies are requested to shed light on possible specific cellular findings as to phenotype and genotype in malignant lymphoma presenting as soft tissue tumors, as already had been done with subcutaneous T-cell lymphoma and primary lymphoma of the bone.