A Unique Coexistence of Colonic Collision and Synchronous Tumors!

Excerpt

A true “collision” tumor represents a coexistence of two adjacent but histologically different malignant neoplasms occurring in the same organ without histological admixture or zone of an intermediate cell population. Such tumors consist of components with different histogenesis and different tumorigenetic pathways representing a mosaic of two concurrent but independent tumors that have “collided” with each other. Such tumors are difficult to diagnose preoperatively, and pathological identification of the dual components is often the only way to make a correct diagnosis [1]. The occurrence of collision tumors is rare in the colon. Reported cases include adenoma of the colon and carcinoid, adenocarcinoma of the colon and carcinoid, non-Hodgkin lymphoma, and adenocarcinoma of the colon [1]. On the other hand, synchronous colorectal cancers refer to two or more primary colorectal carcinomas detected in a single individual at the time of the first diagnosis of colorectal cancer. We present here a case representing a unique example of colonic collision and synchronous tumors. …