Abstract
INTRODUCTION: Transverse colon cancer is uncommon, accounting for 10 % of all colorectal cancers. When tumors invade adjacent organs, like the stomach, the symptoms may overlap with gastric cancer, complicating the diagnosis. Herein, we present an unusual case of transverse colon cancer with gastric invasion mimicking gastric cancer bleeding. PRESENTATION OF CASE: A 79-year-old female presented with generalized weakness and dizziness. The patient was diagnosed with gastric cancer with bleeding at another hospital. Computed tomography (CT) showed an infiltrative mass of approximately 8 × 6.5 cm in the transverse colon and gastric body invasion. Transverse colon cancer with stomach invasion or gastric cancer with transverse colon invasion was suspected based on CT and positron emission tomography. Thus, a colonoscopy and biopsy were performed, and an encircling mass and adenocarcinoma were observed in the transverse colon, respectively. A multidisciplinary assessment confirmed transverse colon cancer that had invaded the stomach. Curative intent surgery was performed, involving en bloc resection and the Deloyers procedure. Pathology confirmed stomach and small bowel invasion without lymph node metastasis; therefore, the pathologic stage was T4bN0. The patient was referred to the oncology department for consultation regarding adjuvant chemotherapy. DISCUSSION: This case underscores the diagnostic challenges posed by overlapping symptoms between gastric and colorectal malignancies. The initial misdiagnosis emphasizes the importance of advanced imaging and a multidisciplinary approach in establishing an accurate diagnosis and treatment plan. CONCLUSION: A multidisciplinary approach is essential to establish an accurate and safe treatment plan for complex transverse colon cancer with adjacent organ invasion.