Tomographic Findings of Gastric Gastrointestinal Stromal Tumor and Correlation With the Mitotic Index

Abstract

-Context -Gastrointestinal stromal tumors are uncommon abdominal neoplasms and can affect any portion of the gastrointestinal tract. Objectives -Describe the tomographic findings of the gastrointestinal stromal tumor of gastric origin, correlating it with the mitotic index. Methods -Twenty-one patients were selected within the period of January 2000 and 2008, with histopathological and immunohistochemical diagnosis of gastric gastrointestinal stromal tumors, who presented computed tomography done before the treatment. The tomographic variables analyzed were lesion topography, dimensions, contours, morphology, pattern and intensity enhancement through venous contrast, growth pattern, invasion of adjacent organs, presence of ulceration, fistula, calcifications, infiltration of mesenteric fat, lymphadenopathy and metastasis. The mitotic index was determined through optic microscopy, counting the number of mitosis figures in 50 high power fields. Results -The tumors were located in the body (66.7%) or gastric fundus (33.3%), with dimensions varying between 4.2 and 21.2 cm (average of 10.5 cm). The growth was predominantly extraluminal (47.6%) or intra/extra luminal (28.6%). The enhancement by venous contrast was heterogeneous in 66.7%. The statistical analysis showed that irregular morphology (P = 0.027) and infiltration of mesenteric fat (P = 0.012) presented correlation with the high mitotic index. Conclusions -In the present study, most part of the tumors were located in the gastric body, with average size of 10.5 cm, presenting central hypo dense area, heterogeneous enhancement through contrast and predominantly extra luminal growth. Irregular morphology and infiltration of mesenteric fat present statistical correlation with high mitotic level. HEADINGS -Gastrointestinal stromal tumors. Spiral computed tomography. Mitotic index.

Effectiveness of radiological findings of gastrointestinal stromal tumors in the prediction of high-risk potential for malignancy: comparison of the NIH and AFIP criteria

“…In a study of O'Neill et al (21) , which assessed the metastatic risk of gastric GISTs by CT features according to the AFIP criteria, they found that tumor size >10 cm, an irregular/lobulated margin and the presence of a solid enhancing component were independently associated with an increased risk of metastatic disease, a higher mitotic count and worse survival. Similar to our study, Pelandre et al (12) . included only gastric GISTs in their study, and found a statistically significant correlation between irregular morphology, mesenteric heterogeneity and high mitotic index.…”

“…GISTs occur at a median age of 60 years in most series (8,12,16,17) . In our study, GISTs have no gender predilection like some other studies (5,13,15) ; however, a male predominance has been shown in the literature (18,19) .…”

“…We did not have any patients with GISTs in large bowel, esophagus, or extra GI tract (1,4,6) . In the literature, there are some studies limited to gastric GISTs (5,12,20,21) . In a study of O'Neill et al (21) , which assessed the metastatic risk of gastric GISTs by CT features according to the AFIP criteria, they found that tumor size >10 cm, an irregular/lobulated margin and the presence of a solid enhancing component were independently associated with an increased risk of metastatic disease, a higher mitotic count and worse survival.…”

“…For instance, a GIST localized at stomach may be stratified into the moderate risk group while it may be in the high-risk group at small intestine. Several studies in the literature concerned about the prediction of malignancy potential in GISTs with CT findings (5,12,13) . However, to our knowledge, the prediction of high-risk potential for malignancy in GISTs by using CT and comparison of relationships between risk groups for malignancy and CT findings according to the NIH and AFIP criteria have not been evaluated together.…”

Development of a Malignancy Potential Binary Prediction Model Based on Deep Learning for the Mitotic Count of Local Primary Gastrointestinal Stromal Tumors

“…The mitotic count of a GIST could be used as a prediction target. Several studies have demonstrated the applicability and clinical value of the mitotic count (27,28).…”