title: Immunohistochemical characterization of Ki-M6 monoclonal antibody in Bouin-fixed, paraffin-embedded sections of normal and neoplastic human tissues.
abstract: A monoclonal antibody (Ki-M6) against the CD 68 antigen, which labels cells of the monocyte/macrophage system, was tested on Bouin-fixed, paraffin-embedded samples of normal, reactive and neoplastic tissues by an avidin-biotin-peroxidase complex method, with the aim of establishing its value in diagnostic pathology. In normal human tissues, Ki-M6 reactivity was confined to the so-called resident macrophages populating normal organs under physiological conditions. Moreover, restricted reactivity against cells of macrophage lineage was observed in reactive and inflammatory lesions. Granulocytes, monocyte/macrophage-related immune accessory cells, and other analysed normal tissue structures did not reveal any reactivity. Ki-M6 was strongly reactive with the cases of benign (4/4) and malignant (15/15) fibrous histiocytomas, in addition to the true histiocytic lymphomas (3/3). Cases of granular cell tumour (2/3) showed strong reactivity with Ki-M6, whereas only few immunoreactive cells, with weak staining, were seen in the other Ki-M6-positive neoplasms [neurofibroma (3/3), benign schwannoma (1/2), ganglioneuroma (1/1), malignant schwannoma (5/9), melanoma (9/28), dermatofibrosarcoma protuberans (1/1), myelomonocytic leukaemia (3/3)]. Among the epithelial malignancies tested (47 cases), Ki-M6 was positive only in renal cell carcinoma (11/14). Malignant lymphomas of the Hodgkin (56 cases) and non-Hodgkin type (67 cases) were uniformly non-reactive. From these data, Ki-M6 appears to be an excellent marker of monocyte/macrophage-related cells and appears to be a reliable indicator for fibrous histiocytomas and true histiocytic malignancies. The availability of this additional antibody capable of staining routinely processed tissue is of practical interest.
authors.affiliation: Division of Pathology, Centro Regionale di Riferimento Oncologico, Istituto Nazionale di Ricovero e Cura a Carattere Scientifico, Aviano, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Gloghini
authors.forename: R
authors.initials: R
authors.lastname: Volpe
authors.forename: V
authors.initials: V
authors.lastname: Canzonieri
authors.forename: A
authors.initials: A
authors.lastname: Carbone
mesh_terms: D000911:Antibodies, Monoclonal / Q000378:metabolism; D006098:Granulocytes / Q000378:metabolism / Q000473:pathology; D018219:Histiocytoma, Benign Fibrous / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D008223:Lymphoma / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology; D008264:Macrophages / Q000378:metabolism* / Q000473:pathology; D009000:Monocytes / Q000378:metabolism* / Q000473:pathology; D009369:Neoplasms / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D009442:Neurilemmoma / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology; D010232:Paraffin
chemical_list: D000911:Antibodies, Monoclonal; D010232:Paraffin