S1621 Bladder in the Colon: A Rare Case of Hematochezia

Abstract

INTRODUCTION: Colorectal cancer is the most common malignancy in the GI tract. Metastatic lesion to the colon are uncommon, accounting for only 1% of all colorectal neoplasms. The most common form of metastatic spread to the bowel is through peritoneal spreading. Hematogenous and lymphatic spread to the colon is reported in breast carcinoma, lung carcinoma, and melanoma. We present a rare cause of colorectal neoplasm. CASE DESCRIPTION/METHODS: A 65yo male with a history of ESRD and urothelial carcinoma presenting with hematochezia for 2 day. Symptoms began abruptly and were painless. He reported dizziness. He denied prior history of similar episodes. Patient denied melena, constipation, or any other GI symptoms. He is not on blood thinners. Of note, patient has chronic hematuria related to his malignancy, requiring blood transfusions. His most recent outpatient labs 1 week prior revealed a hemoglobin of 8.6g/dL. Patient is on neoadjuvant pembrolizumab. Surgical history included a prior bladder biopsy. He had no reported of prior colonoscopy. He is a former smoker with no other toxic habits and no pertinent family history. On admission, HR 110, BP 85/50, and was afebrile, saturating 100% on room air. Exam was remarkable for conjunctival pallor. Rectal exam revealed red blood without notable masses or lesions. Labs were significant for a hemoglobin of 7.1g/dL, creatinine of 3.5 and BUN of 42. The remainder of his CBC and CMP were unremarkable. He was transfused 1unit packed red blood cells and given IV fluids with improvement in his BP. He underwent a colonoscopy which revealed a 4 × 3 cm cecal mass with an adherent clot. The mass was injected with epinephrine, clot was successfully removed, and the mass was biopsied. Additionally, there was blood throughout the colon, and non-bleeding diverticuli in the transverse and sigmoid colon. Pathology revealed high grade carcinoma consistent with metastatic urothelial carcinoma, morphologically similar to his prior TURP specimens. Patient had a follow-up CT C/A/P that showed no other notable metastatic disease with stable bladder mass noted on a surveillance CT scan 3 months prior. Patient went for a right hemicolectomy for further management. Patient had oncologic followup for treatment. DISCUSSION: Although colon malignancy is common, metastatic urothelial cancer isolated in the colon is rare. Managing such cases is difficult as literature is unavailable. Further research is needed to understand methods of metastasis, predicting outcomes, and managing patients.Figure 1.: Cecal mass with notable adherent clot.Figure 2.: Cecal mass status post epinephrine injection and clot removal.