Clinical characteristics and prognosis of gastrointestinal stromal tumors with rare site metastasis (Review)

Gastrointestinal stromal tumors (GIST) are the most common stromal-derived tumors of the gastrointestinal tract and have a potential metastatic capacity in almost half of all cases, with the most common sites of metastasis being the liver and peritoneum. However, there is evidence that GIST metastasizes to sites other than the liver and peritoneum, which poses challenges for clinical diagnosis and treatment. Therefore, the Cochrane and Medline databases were searched via PubMed in July 2022 using relevant keywords to acquire the literature associated with the metastasis of GIST to rare sites published since from 2000 onwards. Study data comprising age, sex, primary location, metastatic site, mean survival time, clinical signs and symptoms, imaging, pathological features immunohistochemical indices, treatment and prognosis were recorded and analyzed. The 118 metastases at rare sites reported in the literature included bone (n=31), lung (n=10), lymph nodes (n=13), intracranial sites (n=13), skin and subcutaneous tissue (n=10), heart (n=7), skeletal muscle (n=7), orbit and choroid (n=6), pancreas (n=3), spleen (n=2), bone marrow (n=1), testis (n=3), scrotum (n=1), epididymis (n=1), penis (n=1), ovary (n=2), cervix (n=1), kidney (n=1), bladder (n=1), adrenal gland (n=2) and thyroid gland (n=2). From the reviewed studies, it may be concluded that when metastases from gastrointestinal stromal tumors occur at rare sites, the initial symptoms may help in the identification of these sites. In addition, the site-dependent imaging of different metastatic locations may further define the metastases, and the findings of pathological or immunohistochemical analyses may be used to confirm the diagnosis.