Characterization of tumour cells in malignant fibrous histiocytomas and other soft tissue tumours in comparison with malignant histiocytes. I. Immunohistochemical study on paraffin sections

Abstract

We have studied the possible origin of histiocytic cells, present in fibrous histiocytomas (MFH) by using immunohistochemistry to demonstrate lysozyme, alpha 1-antitrypsin, alpha 1-antichymotrypsin and receptors for peanut and soy bean agglutinin in tumour cells of MFH compared with their presence in tumour cells of malignant histiocytosis (MH) ('true' histiocytic lymphoma, 'true' histiocytic sarcoma). We included in this study a number of other soft tissue tumours (STT). Lysozyme was detected in half of the cases of malignant histiocytosis (n = 16) but in only two out of 77 MFH. alpha 1-Antitrypsin and alpha 1-antichymotrypsin usually occurred together although the latter was seen in more cases. Both markers were present in majority of cases of MH whereas they were detected in a minority of cases of MFH. MFH cases of the storiform subtype were less frequently stained than the pleomorphic or giant cell subtypes. Receptors for peanut or soy bean agglutinin were detected in nearly all MH cases, whereas their presence was only detected in a small number of MFH. Lysozyme was not detectable in other STT. alpha 1-Antitrypsin and alpha 1-antichymotrypsin were uncommonly present in other STT, except in osteosarcoma and rhabdomyosarcoma. These markers therefore have a limited value as indicators of a possible histiocytic origin of MFH. Lectins showed weak affinity for other STT. In accordance with others, we therefore conclude that the progenitor cell of MFH has to be sought within the undifferentiated mesenchymal cells and that histiocytes themselves probably do not give rise to MFH.

Malignant Fibrous Histiocytoma and Macrophage Differentiation.

“…However, they were also reactive with fibrosarcoma and/or fibroblast cell lines and were thus considered no longer specific for monocyte/macrophages (20,48). All MFH cell lines showed immunohistochemical characteristics very similar to those of fibrosarcoma and fibroblast cell lines (48) as reported by several researchers (5,39,40,55). Positive reaction to the antibodies against type I collagen and prolyl hydroxylase, the enzyme which catalyzes the 4-hydroxylation of proline residues in procollagen, indicates that MFH cells have the capacity to produce collagen (48).…”

“…Early immunohistochemical studies indicated the histiocytic origin of MFH because many histiocytic markers were demonstrated in at least some cases of MFH (6,8,11,23,31). In recent studies, however, most histiocyte markers such as alpha-l -antitrypsin, alpha-1 -antichymotrypsin, lysozyme, Fc receptor, and S100-protein were found to be not specific for macrophages but recognized on various nonhistiocytic cells (40,55). This notion is also true for some monoclonal antibodies incorporated into CD classification.…”

Histiocytic sarcoma: a study of five cases including the histiocyte marker CD163

“…These tumors are believed to arise from undifferentiated mesenchymal cells rather than histiocytes, and typically show pleomorphic and storiform growth patterns. 75,76 Enzymatic and immunophenotypic studies 77,78 have shown that the neoplastic cells in these tumors are negative for histiocytic markers but may contain numerous reactive histiocytes. Despite these subtle morphologic and immunophenotypic differences, clinical history may be the only means of differentiating HS from a metastatic soft-tissue malignancy involving lymph node.…”

An approach to pleomorphic sarcomas: can we subclassify, and does it matter?

“…With the advent of immunohistochemistry and the accessibility of numerous monoclonal antibodies directed against various structural proteins of specific cell types, the phenotype of this tumor was shown to be more closely aligned with a fibroblast than a histiocyte. [3][4][5][6] Furthermore, many, but not all, lesions labeled as 'malignant fibrous histiocytoma' could, upon close scrutiny, be subclassified as lineage-specific sarcomas, an observation that led some to question the existence of MFH as a distinct entity. 7 The extent to which such lesions can be subclassified as sarcomas of alternative type is, in large part, dependent on definitional criteria and the number of ancillary studies a pathologist is willing to bring to bear on the evaluation of a pleomorphic sarcoma.…”