Abstract
BACKGROUND: The progression of cancer from its primary site has been the focus of study of surgeons and oncologists for many decades. Why the primary disease goes on to take the life of some patients while others live out their normal lives after a surgical procedure is only partially understood. METHODS: In a patient with caecal cancer metastatic to the right ovary the clinical, radiologic, surgical and histopathologic findings are presented. Efforts were made to confirm that the disease process was from a single primary site (colon cancer) and not two primary sites (colon cancer and ovarian cancer). RESULTS: In this patient there was progression of ovarian metastases from a right colon cancer simultaneous with near complete disappearance of the primary malignancy. The marked difference in control of the metastatic disease as compared to the primary cancer occurred as multiple treatments of systemic chemotherapy were administered over one year. The specimens of disease removed by surgery showed profound histologic differences at the two sites of cancer. CONCLUSIONS: The primary colon cancer regressed to a small nodule while the ovarian metastases progressed. Efforts to understand and interpret the pathobiology of these observations were made.