title: Histiocytosis-X: clonal culture, histocytochemistry, electron microscopy.
abstract: Pathologic interpretation of an osteolytic lesion from the skull of a 13-month-old boy was amplified by histocytochemistry of cells grown in a methylcellulose clonal culture system. Electron microscopy demonstrated the presence of X granules in the cytoplasm of malignant histiocytes, confirming a diagnosis of histiocytosis-X. Freshly fixed tissue containing histiocytosis-X cells and granulocytes showed histiocytosis-X cells that were positive for alpha-naphthyl acetate esterase (non-specific esterase) and negative with naphthol AS-D chloracetate as the esterase substrate (specific esterase). Clonal cell aggregates, harvested after 6 days' growth in culture, showed histiocytosis-X cells that were positive for both the nonspecific and specific esterases. Differences in staining reactions for the histiocytosis-X cells may be explained on the basis of immaturity of the histiocytosis-X cells growing in culture. This interpretation would support their origin from monocytes, monocytic precursors, or a still less differentiated myelomonocytic precursor cell. Furthermore, gel systems of clonally cultured cells appear to provide a useful tool for the growth and analysis of histiocytosis-X cells.
mesh_terms: D002999:Clone Cells; D004950:Esterases / Q000032:analysis; D006646:Histiocytosis, Langerhans-Cell / Q000201:enzymology / Q000473:pathology*; D006651:Histocytochemistry; D006801:Humans; D007223:Infant; D008297:Male; D008854:Microscopy, Electron; D013194:Staining and Labeling
chemical_list: D004950:Esterases