MALIGNANT HISTIOCYTOSIS - ULTRASTRUCTURAL AND IMMUNOCYTOCHEMICAL CHARACTERIZATION

  • 1 January 1980
    • journal article
    • research article
    • Vol. 104  (1) , 26-29
Abstract
The immunohistochemical and ultrastructural characteristics of involved lymph nodes from 4 patients with typical clinical and histopathological features of malignant histiocytosis are reported. The neoplastic cells in all 4 cases had numerous irregular surface projections and pseudopodia, as well as lobulated or bilobed nuclei with macronucleoli. The cytoplasm contained many lysosomes, mitochondria and polyribosomes, and displayed evidence of phagocytosis. Langerhans'' granules were not identified. The ultrastructural features in the 4 cases were similar, effectively excluded an epithelial origin in each instance and delinated morphological characteristics common to neoplastic macrophages. Intracytoplasmic muramidase (CM), an enzyme marker essentially restricted to cells of myeloid and true histiocytic origin, was identified with the unlabeled immunocytochemical technique and was strongly positive in neoplastic histiocytes at all stages of differentiation. Fine structural features and the presence of CM are useful confirmatory studies in the diagnosis of malignant histiocytosis.