Pericytic mimicry in well-differentiated liposarcoma/atypical lipomatous tumor.

Abstract

Pericytes are modified smooth muscle cells that closely enwrap small blood vessels, regulating and supporting the microvasculature through direct endothelial contact. Pericytes demonstrate a distinct immunohistochemical profile, including expression of smooth muscle actin, CD146, platelet-derived growth factor receptor β, and regulator of G-protein signaling 5. Previously, pericyte-related antigens have been observed to be present among a group of soft tissue tumors with a perivascular growth pattern, including glomus tumor, myopericytoma, and angioleiomyoma. Similarly, malignant tumor cells have been shown to have a pericyte-like immunoprofile when present in a perivascular location, seen in malignant melanoma, glioblastoma, and adenocarcinoma. Here, we examine well-differentiated liposarcoma specimens, which showed some element of perivascular areas with the appearance of smooth muscle (n = 7 tumors). Immunohistochemical staining was performed for pericyte antigens, including smooth muscle actin, CD146, platelet-derived growth factor receptor β, and regulator of G-protein signaling 5. Results showed consistent pericytic marker expression among liposarcoma tumor cells within a perivascular distribution. MDM2 immunohistochemistry and fluorescence in situ hybridization for MDM2 revealed that these perivascular cells were of tumor origin (7/7 tumors), whereas double immunohistochemical detection for CD31/CD146 ruled out an endothelial cell contribution. These findings further support the concept of pericytic mimicry, already established in diverse malignancies, and its presence in well-differentiated liposarcoma. The extent to which pericytic mimicry has prognostic significance in liposarcoma is as yet unknown.

• Authors: Jia Shen, Swati Shrestha, P Nagesh Rao, Greg Asatrian, Michelle A Scott, Vi Nguyen, Paulina Giacomelli, Chia Soo, Kang Ting, Fritz C Eilber, Bruno Peault, Sarah M Dry, Aaron W James
• Journal: Human pathology (Hum Pathol) Vol. 54 Pg. 92-9 (08 2016) ISSN: 1532-8392 [Electronic] United States
• PMID: 27063472 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural)
• Copyright: Copyright © 2016 Elsevier Inc. All rights reserved.

Chemical References

• ACTA2 protein, human
• Actins
• Biomarkers, Tumor
• CD146 Antigen
• MCAM protein, human
• RGS Proteins
• RGS5 protein, human
• MDM2 protein, human
• Proto-Oncogene Proteins c-mdm2
• PDGFRB protein, human
• Receptor, Platelet-Derived Growth Factor beta

Topics

• Actins (analysis)
• Adult
• Aged
• Biomarkers, Tumor (analysis)
• Biopsy
• CD146 Antigen (analysis)
• Cell Differentiation
• Female
• Humans
• Immunohistochemistry
• In Situ Hybridization, Fluorescence
• Lipoma (chemistry, genetics, pathology)
• Liposarcoma (chemistry, genetics, pathology)
• Male
• Middle Aged
• Molecular Mimicry
• Pericytes (chemistry, pathology)
• Phenotype
• Proto-Oncogene Proteins c-mdm2 (analysis, genetics)
• RGS Proteins (analysis)
• Receptor, Platelet-Derived Growth Factor beta (analysis)
• Retrospective Studies