Most malignant fibrous histiocytomas developed in the retroperitoneum are dedifferentiated liposarcomas: a review of 25 cases initially diagnosed as malignant fibrous histiocytoma.
Forty-four samples from 25 cases of retroperitoneal sarcoma initially diagnosed as malignant fibrous histiocytoma were histologically reviewed. Immunohistochemistry for mdm2 and cdk4 was performed on 20 cases. Comparative genomic hybridization was performed on 18 samples from 13 patients. Seventeen cases were reclassified as dedifferentiated liposarcoma. Twenty-one of 32 samples from these patients showed areas of well-differentiated liposarcoma, allowing the diagnosis of dedifferentiated liposarcoma. Immunohistochemistry performed in 15 of these cases showed positivity for mdm2 and cdk4. Comparative genomic hybridization analysis performed on 15 samples from 11 of these patients showed an amplification of the 12q13-15 region. Eight cases were reclassified as poorly differentiated sarcoma. Twelve samples from these patients showed no area of well-differentiated liposarcoma. Immunohistochemistry showed positivity for mdm2 and cdk4 in one of six of these patients and showed positivity for CD34 in another one. Comparative genomic hybridization analysis performed on three samples from two of these patients showed no amplification of the 12q13-15 region but showed complex profiles. This study shows that most so-called malignant fibrous histiocytomas developed in the retroperitoneum are dedifferentiated liposarcoma and that a poorly differentiated sarcoma in this area should prompt extensive sampling to demonstrate a well-differentiated liposarcoma component, immunohistochemistry for mdm2 and cdk4, and if possible, a cytogenetic or a molecular biology analysis.
Coindre
Jean-Michel
JM
Department of Pathology, Institut Bergonié, Bordeaux, France. coindre@bergonie.org.
Mariani
Odette
O
Chibon
Frédéric
F
Mairal
Aline
A
De Saint Aubain Somerhausen
Nicolas
N
Favre-Guillevin
Elizabeth
E
Bui
Nguyen Binh
NB
Stoeckle
Eberhard
E
Hostein
Isabelle
I
Aurias
Alain
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D051358:Cyclin-Dependent Kinase 4; D018844:Cyclin-Dependent Kinases / Q000378:metabolism; D003937:Diagnosis, Differential; D005260:Female; D005784:Gene Amplification; D018219:Histiocytoma, Benign Fibrous / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008080:Liposarcoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009687:Nuclear Proteins; D009693:Nucleic Acid Hybridization; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051736:Proto-Oncogene Proteins c-mdm2; D012186:Retroperitoneal Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D012189:Retrospective Studies
D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2; C495900:CDK4 protein, human; D051358:Cyclin-Dependent Kinase 4; D018844:Cyclin-Dependent Kinases