title: Loss of CD34 and high IGF2 are associated with malignant transformation in solitary fibrous tumors.
abstract: The aim of this study was to characterize the subgroups of solitary fibrous tumor (SFT) and to investigate the expression of different biomarkers including CD34 and IGF2 in malignant transformation. Two hundred and ninety-four (294) SFTs from a single German consultation center of soft tissue tumors were categorized into the new proposal of SFT designation. We found the fibrous variant in 223 (75.9%), the cellular variant in 65 (22.1%), the fat forming variant in 4 (1.4%), and the giant cell-rich variant in 2 (0.6%) cases. Anatomical location, size, mitotic index, necrosis, cellularity, collagenous ropes, and growth pattern of the vessels were recorded. Criteria of malignancy were found in 68 (23%) tumors. Expression of IGF2, IGF1R, CD34, BCL2, CD99, SMA, S100, PanCK, and Ki67 was analyzed immunohistochemically. Low expression of CD34 and high expression of IGF2 were significantly associated with malignant transformation and the metastatic rate. Moreover the presence of necrosis showed the most significant p-value (p<0.004). Of all SFTs, the fibrous variant is the most common, followed by the cellular variant. The fat-forming and giant cell-rich variants are very rare. Low expression of CD34 and high expression of IGF2 are significantly associated with malignant transformation, and might be an interesting target of individualized therapy.
authors.affiliation: Institute of Pathology, Friedrich-Schiller University, Jena, Germany.
authors.forename: Birte
authors.initials: B
authors.lastname: Schulz
authors.affiliation: Department of General, Visceral und Vascular Surgery, Friedrich-Schiller University, Jena, Germany.
authors.forename: Annelore
authors.initials: A
authors.lastname: Altendorf-Hofmann
authors.affiliation: Institute of Pathology, Ludwig-Maximilians-University (LMU), Munich, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kirchner
authors.affiliation: Institute of Pathology, Friedrich-Schiller University, Jena, Germany.
authors.forename: Detlef
authors.initials: D
authors.lastname: Katenkamp
authors.affiliation: Institute of Pathology, Friedrich-Schiller University, Jena, Germany.
authors.forename: Iver
authors.initials: I
authors.lastname: Petersen
authors.affiliation: Institute of Pathology, Friedrich-Schiller University, Jena, Germany; Institute of Pathology, Ludwig-Maximilians-University (LMU), Munich, Germany. Electronic address: thomas.knoesel@med.uni-muenchen.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Knösel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018952:Antigens, CD34 / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002471:Cell Transformation, Neoplastic; D005260:Female; D005858:Germany; D006801:Humans; D007150:Immunohistochemistry; D007335:Insulin-Like Growth Factor II / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D008940:Mitotic Index; D054364:Solitary Fibrous Tumors / Q000378:metabolism* / Q000473:pathology; D046888:Tissue Array Analysis; D055815:Young Adult
chemical_list: D018952:Antigens, CD34; D014408:Biomarkers, Tumor; C035170:IGF2 protein, human; D007335:Insulin-Like Growth Factor II
keywords: CD34; IGF2; Immunohistochemistry; Malignant potential; Solitary fibrous tumors