Summary

A 41-year-old man with no medical history presented with 2 weeks of nausea, vomiting, a new palpable abdominal mass, constipation and a 14kgweight loss. On admission, CT abdomen and pelvis demonstrated a 6.9×3.7 cm soft-tissue abdominal mass deep to and invading the lower anterior abdominal wall with tethering of the urinary bladder and potential involvement of the urachus. Subsequently, a biopsy demonstrated a low-grade spindle cell neoplasm compatible with inflammatory myofibroblastic tumour with immunostain positive for smooth muscle actin and desmin and negative for CD21, CD117, DOG-1, TKE-1, mdm2, CD34 and ALK. One week following admission, he underwent en bloc excision of the mass including abdominal wall (umbilicus, portions of rectus sheath and muscle), bladder dome, right colon and a segment of small bowel. Final pathology of the mass confirmed an inflammatory myofibroblastic tumour, and his postoperative course was uneventful.