肌纤维母细胞瘤伴黏液样变性1例并文献复习OACSTPCD

Myofibroblastoma(MFB)with myxoid degeneration is a rare benign mesenchymal tumor.A case of a 42-year-old female has been found a painless mass in the right inguinal region for 1 year.The mass was smooth on the surface,nodular,and gray-brown on the cross-section.Histologically,the tumor had a myxoid-rich background,with round or short spindle-shaped cells arranged in irregular bundles,eosinophilic cytoplasm,and some nuclei with prominent vacuoles.Immunohistochemistry showed that the tumor cells were diffusely positive for cluster of differentiation 34(CD34)and desmin,partially positive for smooth muscle actin(SMA),cluster of differentiation 56(CD56),and erythroblast transformation-specific related gene(ERG),with a proliferation index Ki-67 of about 5%.Fluorescence in situ hybridization(FISH)revealed a positive deletion of the retinoblastoma protein 1(RB1)gene and negative for nuclear receptor subfamily 4 group a member 3(NR4A3)and Ewing sarcoma breakpoint region 1(EWSR1)genes.Post-surgical follow-up for 3 to 24 months showed no local recurrence or distant metastasis.Diagnosis and differential diagnosis of MFB with myxoid degeneration depend on clinicopathological features,immunohistochemistry,and genetic testing.Simple surgical resection is the primary treatment,offering a good prognosis with no significant risk of recurrence.