Figure 3From: Three synchronous primary carcinomas in a patient with HNPCC associated with a novel germline mutation in MLH1: Case reportThree immunohistochemical stains (40×) from the patient's ureteral tumor and a selected colon tumor. The colon and ureteral cancers stained negative for MLH1 and positive for MSH2. Both colon tumors stained negative for cytokeratin 7 and positive for cytokeratin 20, whereas the ureteral tumor stained positive for both cytokeratins, demonstrating a distinct organ of origin for each tumor type and thus discounting the possibility that either tumor type is a metastasis of the other. Data not shown for positive controls.Back to article page