Retroperitoneal Abscess Revealing Ascending Colon Adenocarcinoma: A Case Report.

Colon cancer is a common malignancy that can pose significant diagnostic and therapeutic challenges, especially when complicated by atypical presentations such as retroperitoneal abscess formation. We present the case of a 50-year-old Caucasian man with no significant medical history who initially presented in the emergency department due to a right lumbar abscess that had been incised at another facility. Imaging revealed a retroperitoneal abscess confined to the retroperitoneum. Initial conservative management with antibiotics and drainage was undertaken; however, subsequent imaging revealed communication with the ascending colon. The patient subsequently underwent a right hemicolectomy. Histopathological analysis confirmed a moderately differentiated adenocarcinoma of the colon, and the patient was referred for oncological evaluation. This case highlights the importance of considering underlying malignancy in atypical abscess presentations and emphasizes the role of advanced imaging and timely surgical intervention in improving outcomes.