Patients with colorectal carcinoma stage I have a high 5-year survival rate, and tumour recurrence is detected in only approximately 5%–10% of patients.1 ,2 Most recurrences present as metachronous haematogenic metastases, typically to the liver and lungs, but generally accepted pathomorphological risk factors have not been defined, as adjuvant treatment is currently not recommended for this stage.1 ,3 However, the introduction of colorectal cancer screening programmes has contributed to increased detection of colorectal carcinoma in early stages; therefore, it is also important to define the risk of metachronous haematogenic metastases in patients with early-stage colorectal carcinoma. In addition, the rapid progress of imaging techniques (eg, MRI) involved in the diagnosis of colorectal carcinoma may challenge the pathologist. Several studies indicate that particularly the invasion of extramural veins (EMVI) is associated with an increased risk of metachronous haematogenic metastases. Considering the anatomical structure of the vessels in the mesocolon/mesorectum, the question arises whether conventional dissection methods result in reliable detection of EMVI. Since the vessels are orientated approximately at a right angle to the bowel wall, only a portion of these vessels is assessable by conventional, perpendicular sampling. In a study of colorectal carcinoma stage II, we have recently shown that EMVI is …