Low Risk Rectal Gastrointestinal Stromal Tumors Recurrence 12 Years After Surgery

The modified NIH (National Institute of Health) risk grading categorizes GIST into four risk grades according to tumor size, location, mitotic count, and tumor rupture, namely: very low risk, low risk, intermediate risk, and high risk. A higher risk grade indicates a higher risk of tumor recurrence and metastasis. Low-risk GIST refer to GIST with a tumor size of 2–5 cm, mitotic count <5/50 HPF, and without rupture. Unlike the grades of medium and high-risk GIST, low-risk GIST does not take the primary site of tumor into consideration. The possibility of recurrence and metastasis still exists for low-risk GIST in special sites even more than 10 years after surgery.