myoepithelioma of soft tissue
Wednesday 10 June 2009
Definition: Soft tissue myoepithelioma is a rare tumor displaying myoepithelial elements within a hyalinized to chondromyxoid stroma and lacking obvious ductal differentiation. The histogenesis is unclear and most are benign, but some behave in a malignant fashion.
In the recent WHO classification of tumors of soft tissue and bone, myoepithelioma is considered to be part of a spectrum that also embrases mixed tumor and parachordoma.
They morphologically resemble mixed tumor of the salivary glands (also known as pleomorphic adenoma), a tumor characterized by deregulated expression of PLAG1 or HMGA2.
IHC positivity for EMA, CK AE1/AE3, S100, calponin and SMA.
Heterogeneous genetic profiles in soft tissue myoepitheliomas. Hallor KH, Teixeira MR, Fletcher CD, Bizarro S, Staaf J, Domanski HA, von Steyern FV, Panagopoulos I, Mandahl N, Mertens F. Mod Pathol. 2008 Nov;21(11):1311-9. PMID: 18604193
Hinze P, Feyler S, Berndt J, Knolle J, Katenkamp D. Malignant myoepithelioma of the vulva resembling a rhabdoid tumour. Histopathology. 1999 Jul;35(1):50-4. PMID: 10383714
Cytogenetic analysis of a primary salivary gland myoepithelioma.
el-Naggar AK, Lovell M, Callender DL, Ordonez NG, Killary AM
Cancer genetics and cytogenetics. 1999 ; 113 (1) : 49-53.