Is an intermediate-risk gastric stromal tumor a malignant tumor?

Generally, whether an intermediate-risk gastrointestinal stromal tumor (GIST) of the stomach is malignant depends on analysis of the tumor size and the number of mitotic figures. If the gastric GIST is larger than 5 cm in diameter or has a high number of mitotic figures, it may be considered malignant. Conversely, if the tumor is smaller than 5 cm and has few mitotic figures, it is usually not classified as malignant. It is recommended to seek medical attention promptly, clarify the underlying cause, and undergo symptomatic treatment under the guidance of a qualified physician. The detailed analysis is as follows:

When a gastric GIST is larger than 5 cm in diameter, or is smaller than 5 cm but has a high number of mitotic figures, this type of intermediate-risk GIST has a higher malignant potential. It may invade surrounding tissues or metastasize to distant sites, posing a threat to the patient's life. In such cases, the tumor is regarded as malignant.

When a gastric GIST is smaller than 5 cm and has few mitotic figures, although categorized as intermediate-risk, it may remain non-metastatic and non-invasive for many years. Such tumors can be considered "borderline" lesions—intermediate between benign and malignant—but are not entirely equivalent to malignant tumors.

Tissue pathological examination via biopsy or after surgical resection can definitively determine the histological type, degree of differentiation, and presence of malignant features.