Clonal composition of malignant fibrous histiocytoma: analysis by PCR-based assay of the human androgen receptor gene (HUMARA).
Malignant fibrous histiocytoma (MFH), the most common soft-tissue sarcoma, consists mainly of two different cell populations: histiocytelike and fibroblastlike cells. It has been suggested to contain a large amount of reactive histiocytes and fibroblasts hard to distinguish from the tumor cells. In this study, the clonality of MFH was determined by analyzing the patterns of X chromosome inactivation at the human androgen receptor gene (HUMARA) using DNA samples from archival snap-frozen and paraffin-embedded tissues. All the eleven informative female heterozygotes without severe inflammation showed the monoclonal pattern; 8 storiform-pleomorphic (6 distinct, 2 relative monoclonal pattern) and 3 myxoid (3 distinct monoclonal pattern) subtype. Although normal tissue DNA, amplifiable by the polymerase chain reaction, valid for the assay was not available in these cases, statistically at least 5 cases are monoclonal (p = 0.037 <0.05), even when markedly skewed lyonization were to primarily exist in the normal tissue at the highest rate as ever reported (33%). Experiments using the mixture of monoclonal and polyclonal DNA at varying ratios have suggested that a distinct monoclonal pattern is obtained only when the monoclonal component exceeds 80%. Our study demonstrates that most cells that are present in MFH are monoclonal in origin which may be the population of tumor cells.
Fujita
M Q
MQ
Department of Pathology, Osaka University Medical School, Osaka, Japan.
Hashida
N
N
Shin
M
M
Nakanishi
H
H
Yoshihara
W
W
Aozasa
K
K
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002999:Clone Cells; D017931:DNA Primers; D004273:DNA, Neoplasm / Q000032:analysis / Q000235:genetics; D005260:Female; D018219:Histiocytoma, Benign Fibrous / Q000235:genetics* / Q000473:pathology / Q000648:ultrastructure*; D006801:Humans; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011944:Receptors, Androgen / Q000235:genetics*
D017931:DNA Primers; D004273:DNA, Neoplasm; D011944:Receptors, Androgen