Clinicopathological Importance of Colorectal Medullary Carcinoma: Retrospective Cohort Study

Medullary carcinoma (MC) is a rare tumor with solid growth pattern without glandular differentiation and constitute less than 1% of colorectal cancer. Lymph node positivity and distant organ metastasis were reported to be lower than other poorly differentiated adenocarcinomas. Therefore, the diagnosis of MC is pathologically important in terms of follow-up and treatment. MC is commonly localized in the right colon, has a large tumor size, and is mostly diagnosed in the T4 stage. As MC most likely have defects in DNA MMR, the correct pathological diagnosis is important for the postoperative treatment and the prognosis of the patients.