Intravenous leiomyomatosis: an unusual intermediate between benign and malignant uterine smooth muscle tumors

• Published in: Modern pathology Vol. 29; no. 5; pp. 500 - 510
• Main Authors: Ordulu, Zehra, Nucci, Marisa R, Dal Cin, Paola, Hollowell, Monica L, Otis, Christopher N, Hornick, Jason L, Park, Peter J, Kim, Tae-Min, Quade, Bradley J, Morton, Cynthia C
• Format: Journal Article
• Language: English
• Published: New York Nature Publishing Group US 01.05.2016; Elsevier Limited
• Subjects: 13/106; 13/51; 14/32; 38/61; 631/208/1405; 631/337/103; 631/67/1517; 692/420/755; 692/699/2732; Cytogenetic Analysis; Female; Fibroids; Gene Expression Profiling; Humans; Hybridization; Informatics; Laboratory Medicine; Leiomyoma - genetics; Leiomyoma - pathology; Leiomyomatosis - genetics; Leiomyomatosis - pathology; Medicine; Medicine & Public Health; original-article; Pathogenesis; Pathology; Smooth muscle; Smooth Muscle Tumor - genetics; Smooth Muscle Tumor - pathology; Transcriptome; Tumors; Uterine Neoplasms - genetics; Uterine Neoplasms - pathology; Uterus; Vascular Neoplasms - genetics; Vascular Neoplasms - pathology; Women; United States > US
• ISSN: 0893-3952; 1530-0285
• DOI: 10.1038/modpathol.2016.36

Intravenous leiomyomatosis is an unusual smooth muscle neoplasm with quasi-malignant intravascular growth but a histologically banal appearance. Herein, we report expression and molecular cytogenetic analyses of a series of 12 intravenous leiomyomatosis cases to better understand the pathogenesis of intravenous leiomyomatosis. All cases were analyzed for the expression of HMGA2, MDM2, and CDK4 proteins by immunohistochemistry based on our previous finding of der(14)t(12;14)(q14.3;q24) in intravenous leiomyomatosis. Seven of 12 (58%) intravenous leiomyomatosis cases expressed HMGA2, and none expressed MDM2 or CDK4. Colocalization of hybridization signals for probes from the HMGA2 locus (12q14.3) and from 14q24 by interphase fluorescence in situ hybridization (FISH) was detected in a mean of 89.2% of nuclei in HMGA2-positive cases by immunohistochemistry, but in only 12.4% of nuclei in negative cases, indicating an association of HMGA2 expression and this chromosomal rearrangement ( P =8.24 × 10 −10 ). Four HMGA2-positive cases had greater than two HMGA2 hybridization signals per cell. No cases showed loss of a hybridization signal by interphase FISH for the frequently deleted region of 7q22 in uterine leiomyomata. One intravenous leiomyomatosis case analyzed by array comparative genomic hybridization revealed complex copy number variations. Finally, expression profiling was performed on three intravenous leiomyomatosis cases. Interestingly, hierarchical cluster analysis of the expression profiles revealed segregation of the intravenous leiomyomatosis cases with leiomyosarcoma rather than with myometrium, uterine leiomyoma of the usual histological type, or plexiform leiomyoma. These findings suggest that intravenous leiomyomatosis cases share some molecular cytogenetic characteristics with uterine leiomyoma, and expression profiles similar to that of leiomyosarcoma cases, further supporting their intermediate, quasi-malignant behavior.