An immunohistochemical and clinicopathological study of granulocytic sarcoma ('chloroma').

A small series of granulocytic sarcomas (GS) or 'chloromas' has been studied by means of conventional histology and immunohistochemistry. The latter was found to be most useful in the diagnosis and characterization of these neoplasms, which are rare in Great Britain. Polytypic antisera to leukocyte elastase and cathepsin G have proved to be most useful, giving intense staining in all cases. These two markers are more specific than muramidase (lysozyme) and alpha 1-antitrypsin, since, unlike the latter two, they do not stain histiocytic cells. The results of staining with two monoclonal antisera, AGF 4.48 and AGF 4.36, are also described. In addition, the clinicopathological details of the seven cases are summarized and the literature is briefly surveyed.