This Article Order Full text via Infotrieve Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Brooks, J. J. Search for Related Content PubMed PubMed Citation Articles by Brooks, J. J.

American Journal of Pathology, Vol 125, 113-123, Copyright © 1986 by American Society for Investigative Pathology

REGULAR ARTICLES

The significance of double phenotypic patterns and markers in human sarcomas. A new model of mesenchymal differentiation

JJ Brooks

Six soft-tissue sarcomas with two separate and juxtaposed histologic patterns were selected for immunohistochemical analysis. The first pattern was represented by five phenotypes (schwannian-skeletal muscle [Triton], cartilagenous, synovial, adipocytic, and smooth muscle). In each case the second histologic pattern resembled the fibrohistiocytic phenotype, ie, malignant fibrous histiocytoma (MFH). No other histologic patterns were identified. Appropriate cell markers were demonstrated in each of the first patterns; these were not detected in the second patterns. In contrast, the second pattern in all cases expressed alpha 1-antichymotrypsin, a marker commonly found in fibrohistiocytic lesions; this was not identified in any of the first patterns. This loss of one cell-specific marker and gain of another is termed the "antigenic shift" phenomenon and appeared to foretell the emergence of a true second phenotype (the same in each of these cases, which could be termed "dedifferentiated" sarcomas). Therefore, it is hypothesized that MFH is a final common pathway for some types of sarcomas and is the result of tumor progression or "dedifferentiation." The practical implications of this hypothesis concern the approach to sarcoma differential diagnosis and the meaning of an MFH pattern in both metastatic and primary sites. On a theoretic level, this hypothesis and the antigenic shift phenomenon force a reconsideration of the pathways of soft-tissue differentiation. A new model of mesenchymal differentiation incorporating these concepts is described and supported. It provides an explanation for a number of facts in soft- tissue pathology, and its predictions can be tested.

This article has been cited by other articles:

				N. H. Segal, P. Pavlidis, C. R. Antonescu, R. G. Maki, W. S. Noble, D. DeSantis, J. M. Woodruff, J. J. Lewis, M. F. Brennan, A. N. Houghton, et al. Classification and Subtype Prediction of Adult Soft Tissue Sarcoma by Functional Genomics Am. J. Pathol., August 1, 2003; 163(2): 691 - 700. [Abstract] [Full Text] [PDF]

				I Kudawara, N Araki, H Nakanishi, M Mano, and S Ishiguro Malignant mesenchymoma of the lower leg J. Clin. Pathol., November 1, 2001; 54(11): 877 - 879. [Abstract] [Full Text] [PDF]

				C. D.M. Fletcher, P. Gustafson, A. Rydholm, H. Willen, and M. Akerman Clinicopathologic Re-Evaluation of 100 Malignant Fibrous Histiocytomas: Prognostic Relevance of Subclassification J. Clin. Oncol., June 15, 2001; 19(12): 3045 - 3050. [Abstract] [Full Text] [PDF]

				D. L. Todd, R. Laucirica, M. L. Ostrowski, R. Brown, and L. D. Truong Transitional Cell Carcinoma Metastatic to Lung, With Dedifferentiation Into Small Cell Undifferentiated Carcinoma International Journal of Surgical Pathology, October 1, 1994; 2(2): 157 - 162. [Abstract] [PDF]

				L. Barnes and A. Kanbour Malignant Fibrous Histiocytoma of the Head and Neck: A Report of 12 Cases Arch Otolaryngol Head Neck Surg, October 1, 1988; 114(10): 1149 - 1156. [Abstract] [PDF]