Key Clinical MessageWe report a case of a 21‐year‐old male with stage IIIB sigmoid colon adenocarcinoma who experienced atypical chest pain post‐adjuvant chemotherapy with Capecitabine (5‐FU prodrug). Evaluation revealed an unexpectedly detected interventricular septum hemangioma. Due to the vasospasm effect of chemotherapy presenting with semi‐ischemia, conservative management was chosen for atypical presentation.