Purpose The gastrointestinal tract's most commonly occurring primary mesenchymal tumor is the gastrointestinal stromal tumor (GIST). However, few cases worldwide were reported associated with renal cell carcinoma (RCC). Therefore, we aimed to identify the association of genitourinary tumors in patients with GIST in our tertiary care hospital in Saudi Arabia. Methods We identified all patients in the pathology department database with the diagnosis of GIST. We excluded duplicate and recurrent cases. We examined patients’ files for the presence of RCC, adrenal tumors, or other genitourinary cancer. Results From 2003 to 2022, 170 patients had a histopathologic diagnosis of primary GIST, 100 men and 70 women, median age of 63 (± 15.5) years at the time of diagnosis. The site of primary GIST was gastric 103, small bowel 43, mesenteric 5, omentum/peritoneum 7, abdomen 4, isolated adrenal 1, and other 7. Eight patients had associated genitourinary cancer. Three patients had RCC (two clear cell RCC and one radiologic diagnosis only), three had adrenal tumors (one adrenal carcinoma, one an isolated adrenal GIST and one pheochromocytoma), and two had a tumor invading the urinary bladder. Although the cohort included 63 men aged 60 years old or above (median 71 ± 8.7 years, range 60–94), none demonstrated clinical prostatic carcinoma. Conclusion We report the rare association between GIST tumors and primary genitourinary cancer, mainly RCC and adrenal tumors. Also, we identified a secondary invasion of the urinary bladder. Unlike the reported series, none of the older male patients had clinical prostate cancer.

Purpose The gastrointestinal tract's most commonly occurring primary mesenchymal tumor is the gastrointestinal stromal tumor (GIST). However, few cases worldwide were reported associated with renal cell carcinoma (RCC). Therefore, we aimed to identify the association of genitourinary tumors in patients with GIST in our tertiary care hospital in Saudi Arabia. Methods We identified all patients in the pathology department database with the diagnosis of GIST. We excluded duplicate and recurrent cases. We examined patients’ files for the presence of RCC, adrenal tumors, or other genitourinary cancer. Results From 2003 to 2022, 170 patients had a histopathologic diagnosis of primary GIST, 100 men and 70 women, median age of 63 (± 15.5) years at the time of diagnosis. The site of primary GIST was gastric 103, small bowel 43, mesenteric 5, omentum/peritoneum 7, abdomen 4, isolated adrenal 1, and other 7. Eight patients had associated genitourinary cancer. Three patients had RCC (two clear cell RCC and one radiologic diagnosis only), three had adrenal tumors (one adrenal carcinoma, one an isolated adrenal GIST and one pheochromocytoma), and two had a tumor invading the urinary bladder. Although the cohort included 63 men aged 60 years old or above (median 71 ± 8.7 years, range 60–94), none demonstrated clinical prostatic carcinoma. Conclusion We report the rare association between GIST tumors and primary genitourinary cancer, mainly RCC and adrenal tumors. Also, we identified a secondary invasion of the urinary bladder. Unlike the reported series, none of the older male patients had clinical prostate cancer.