title: High grade malignant lymphoma with clinical characteristics and immunophenotype of natural killer cells.
abstract: The malignant proliferation of natural killer (NK) cells which are morphologically characterized as large granular lymphocytes (LGL) is a well known clinical entity which was named after its morphological appearance as LGL-leukemia/lymphoma. Similar to non-malignant NK-cells, these tumors can be divided into those which express the CD3-T-cell receptor complex and those which do not. The CD3-positive type of LGL-leukemia is immunophenotypologically characterized by the expression of CD16, and variably CD 56 and CD 57, and generally follows a more indolent course. In contrast, malignant proliferations of CD3-negative LGL express either CD16 or CD 56, and only occasionally CD 57 on their cell surface. Clinically, CD3-negative NK-lymphomas tend to progress rapidly. We report here the case of a high grade malignant lymphoma which was characterized by an immunophenotype typical for CD3-negative NK-cells (CD2+, CD3-, CD16+, CD56(+), CD57-). The disease proved to be rapidly fatal despite aggressive chemotherapy. Interestingly, the patient suffered from a high turn over pancytopenia, which also characterizes NK-cell leukemias/lymphomas of the LGL-type. However, our patient's lymphatic cells appeared highly immature, and cytoplasmic granules, characteristic for LGL-cells, could not be discerned either microscopically or electronmicroscopically. Furthermore, the malignant lymphatic population had the T-cell receptor beta-chain rearranged. We therefore concluded that our patient might have suffered from a malignant proliferation of a putative precursor cell intermediate between T-cells and NK-cells.
authors.affiliation: Department of Internal Medicine, University Hospital Zürich, Switzerland.
authors.forename: B
authors.initials: B
authors.lastname: Schleiffenbaum
authors.forename: R
authors.initials: R
authors.lastname: Rüegg
authors.forename: D
authors.initials: D
authors.lastname: Zimmermann
authors.forename: J
authors.initials: J
authors.lastname: Fehr
mesh_terms: D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001761:Bleomycin / Q000008:administration & dosage; D001853:Bone Marrow / Q000473:pathology; D003520:Cyclophosphamide / Q000008:administration & dosage; D004317:Doxorubicin / Q000008:administration & dosage; D005047:Etoposide / Q000008:administration & dosage; D006801:Humans; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000276:immunology / Q000473:pathology*; D007958:Leukocyte Count; D008223:Lymphoma / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D008297:Male; D011241:Prednisone / Q000008:administration & dosage; D013154:Spleen / Q000473:pathology; D013156:Splenectomy; D013921:Thrombocytopenia; D014750:Vincristine / Q000008:administration & dosage
chemical_list: D001761:Bleomycin; D014750:Vincristine; D005047:Etoposide; D004317:Doxorubicin; D003520:Cyclophosphamide; D011241:Prednisone