A patient presenting with a large infiltrative mass in the abdominal wall likely has what type of tumor?

Infiltrative masses in the abdominal wall can be characteristic of a desmoid tumor, which is a type of soft tissue tumor that arises from the fibrous tissue. Desmoid tumors are known for their local aggressiveness and tendency to infiltrate surrounding tissues without metastasizing to distant sites. These tumors, also referred to as aggressive fibromatosis, often occur in the abdominal wall, particularly in patients with a history of abdominal surgery or among individuals with familial adenomatous polyposis (FAP).

Their histological features include a proliferation of spindle-shaped fibroblasts with a low mitotic rate, and they often show infiltrative growth patterns, making their surgical removal challenging. This infiltrative behavior is a key distinguishing factor that aligns with the presentation of a large mass in the abdominal wall.

Other types of tumors, such as liposarcoma, malignant fibrous histiocytoma, and sarcomas, typically exhibit different characteristics in terms of their cellular origin, growth pattern, and behavior. While they may also present as masses in the abdominal wall, their typical presentations and management differ from that of desmoid tumors.