[Differential diagnosis of pseudolymphomas].

The term pseudolymphoma indicates the physician's opinion concerning the prognosis but is not a diagnosis. Several benign conditions mimic lymphomas, but neoplastic lymphocytes may also be overcome by the organism. In some "pseudolymphomas" the malignant lymphocytes are just kept in check for some time but finally the outcome is fatal. Modern techniques to classify cells by monoclonal antibodies and lectins indicate that proliferations of non-lymphocytes, like histiocytes, Langerhans cells, or Merkel cells, may simulate malignant lymphomas too, so a new type of pseudolymphomas has to be acknowledged. The most important question, however, whether the proliferation is malignant or benign, cannot be answered satisfactorily yet, at least with borderline cases or very early proliferation.