Abstract
Rhabdoid tumors are rare and aggressive neoplasms, first described in the kidney, but they have also been reported in various extrarenal sites, including the gastrointestinal tract. Gastric involvement is particularly unusual, often presenting as an adenocarcinoma with rhabdoid features. This type of tumor poses a diagnostic challenge, requiring histological, immunohistochemical, and cytogenetic analyses. Due to the aggressive nature of these tumors, early diagnosis and prompt surgical intervention are essential, although the prognosis remains poor. We report a case of a man with an upper gastrointestinal bleeding where both gastrointestinal endoscopy, colonoscopy, and even the abdominal scan failed to identify the origin of bleeding; considering these results, a Weinberg procedure was performed. In light of the continued deterioration, antrectomy was deemed necessary, after which anatomopathological findings were consistent with an undifferentiated adenocarcinoma of the stomach exhibiting rhabdoid features.