Stage III Small Intestinal, Esophageal, Colorectal, Mesenteric, and Peritoneal Gastrointestinal Stromal Tumor AJCC v8

**Semantic type:** Neoplastic Process

**Definition:** Stage III includes: IIIA: (T1, N0, M0, High Mitotic Rate); (T4, N0, M0, Low Mitotic Rate); IIIB: (T2, N0, M0, High Mitotic Rate); (T3, N0, M0, High Mitotic Rate); (T4, N0, M0, High Mitotic Rate). T1: Tumor measuring 2 cm or less. T2: Tumor measuring more than 2 cm but not more than 5 cm. T3: Tumor measuring more than 5 cm but not more than 10 cm. T4: Tumor measuring more than 10 cm in greatest dimension. N0: No regional lymph node metastasis or unknown lymph node status. M0: No distant metastasis. High Mitotic Rate: Over 5 mitoses per 5 square millimeters, or per 50 HPF. Low Mitotic Rate: Five or fewer mitoses per 5 square millimeters, or per 50 HPF. (AJCC 8th ed.)

**Synonyms:** - Stage III Small Intestinal, Esophageal, Colorectal, Mesenteric, and Peritoneal GIST AJCC v8 - Stage III Small Intestinal, Esophageal, Colorectal, Mesenteric, and Peritoneal Gastrointestinal Stromal Tumor (GIST)