title: Malignant histiocytosis and related tumors. A clinicopathologic study of 42 cases using cytological, histochemical and ultrastructural parameters.
abstract: Light and electron microscopical, immunohistochemical and clinical characteristics in 42 cases of malignant neoplasms, arising from true histiocytes, are described. These were separated in a lymphoma-like subtype, called true histiocytic lymphoma (29 patients) and a disseminated variant, called malignant histiocytosis (9 patients). In addition 4 related histiocytic tumors are discussed, including 2 tumors arising from interdigitating cells. Sinus pattern and cytologic features, especially 'window' nuclei, are emphasized as diagnostic criteria. Erythrophagocytosis was not a constant finding. Electron microscopic features, presence of acid phosphatase, acid alpha-naphthylacetate esterase, lysozyme, alpha 1-antitrypsin, alpha 1-antichymotrypsin, Ia-antigen and absence of B- and T-cell markers, were important in establishing the histiocytic nature or excluding a non-histiocytic tumor. A distinct male predominance existed (male:female = 2.5:1) with a higher relapse free period in females (p = 0.032). A high number of mitotic figures appeared to be a favourable sign, p = 0.020 and 0.019, for remission rate and relapse free period respectively. The degree of cell differentiation and the immunohistochemical pattern did not show a correlation with remission and relapse free period. Extranodal involvement and the presence of short profiles of endoplasmic reticulum were prognostically unfavourable signs. True histiocytic lymphomas showed a higher remission rate (p = 0.041) and relapse-free period (p = 0.017) than malignant histiocytosis.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002467:Cell Nucleus / Q000648:ultrastructure; D002648:Child; D002675:Child, Preschool; D005260:Female; D006644:Histiocytes / Q000648:ultrastructure; D018219:Histiocytoma, Benign Fibrous / Q000473:pathology* / Q000628:therapy / Q000648:ultrastructure; D006651:Histocytochemistry; D006801:Humans; D007223:Infant; D008206:Lymphatic Diseases / Q000473:pathology* / Q000628:therapy / Q000648:ultrastructure; D016403:Lymphoma, Large B-Cell, Diffuse / Q000473:pathology* / Q000628:therapy / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged