[Variation in morphology or two entities?].

A 37-year-old patient presented with B symptoms. On examination, hypodense liver lesions, multiple enlarged and partly confluent lymph nodes in the upper abdomen and retroperitoneum, as well as disseminated splenic and pulmonary foci were detected. Biopsies of a tumor in the coecum and the liver led to the diagnosis of an adenocarcinoma of the colon. In molecular pathology, microsatellite instability was detected. The post-neoadjuvant surgical specimen showed an unusual morphology and the question arose whether a second tumor should be considered.