Rectus abdominis desmoid tumor confirmed by ultrasound-guided biopsy. Histochemical stains were positive for smooth muscle actin and beta-catenin, and negative for AE1/AE3, S100, desmin, and CD34. 

There is an important association of abdominal wall desmoid tumors and pregnancy, and this young woman noticed this mass about one year after cessation of breastfeeding. This was surgically excised.