Myolipoma : HMGA2

Comments:
Cytogenetics of Myolipoma: Cytogenetic alterations involving high mobility group protein 2 (HMGA2) gene at 12q14-15 have been reported in a few cases of myolipoma of soft tissues. Translocation t(9;12)(p22;q14) resulting in fusion of HMGA2 and C9orf92 has been reported in one myolipoma. HMGA2 immunoreactivity (nuclear) is seen in 60% of myolipomas.

HMGA2 encodes a small transcription factor that regulates gene expression by binding to the AT-rich regions in the minor groove of DNA double helix. It is highly expressed in embryonic stem cells and regulates cell growth and differentiation during embryogenesis. Its expression tapers off in later stages of development and in adulthood.

Rearrangements of HMGA2 resulting in its overexpression play a pathogenetic role in many benign and malignant epithelial and mesenchymal (lipomatous and smooth muscle) tumors.

Image source: Mansoori B et al. HMGA2 as a Critical Regulator in Cancer Development. Genes 2021, 12(2), 269; https://doi.org/10.3390/genes12020269; used under Creative Common CC BY License.