Mixed Tumor, Myoepithelioma of Soft Tissue
Myoepithelioma is defined as a tumor composed entirely of neoplastic cells with myoepithelial differentiation. The term mixed tumor is used when tubular and/or ductal differentiation is present. However, it is now widely accepted that myoepithelioma and mixed tumor of the soft tissues represent a spectrum of closely related tumors with overlapping histologic features and similar clinical behavior. Malignant myoepithelioma or myoepithelial carcinoma represents the malignant counterpart.
Soft tissue myoepithelial tumors are uncommon.
They occur over a wide age range, having been reported in infants and adults. The peak age is between the third and fifth decades (Kilpatrick et al. 1997; Michal and Miettinen 1999; Hornick and Fletcher 2003; Gleason and Fletcher 2007; Rekhi et al. 2012; Thway and Fisher 2014; Jo and Fletcher 2015).
References and Further Reading
- Antonescu, C. R., Zhang, L., Chang, N. E., et al. (2010). EWSR1-POU5F1 fusion in soft tissue myoepithelial tumors. A molecular analysis of sixty-six cases, including soft tissue, bone, and visceral lesions, showing common involvement of the EWSR1 gene. Genes, Chromosomes & Cancer, 49, 1114–1124.CrossRefGoogle Scholar
- Flucke, U., Tops, B. B., Verdijk, M. A., van Cleef, P. J., van Zwam, P. H., Slootweg, P. J., Bovée, J. V., Riedl, R. G., Creytens, D. H., Suurmeijer, A. J., & Mentzel, T. (2012). NR4A3 rearrangement reliably distinguishes between the clinicopathologically overlapping entities myoepithelial carcinoma of soft tissue and cellular extraskeletal myxoid chondrosarcoma. Virchows Archiv, 460, 621–628.CrossRefGoogle Scholar