Differentiating the undifferentiated: immunohistochemical profile of medullary carcinoma of the colon with an emphasis on intestinal differentiation

摘要: Undifferentiated or medullary carcinoma is characterized by its distinct histologic appearance and relatively better prognosis compared to poorly differentiated colonic carcinoma. These 2 entities may be difficult differentiate light microscopy alone. Only limited immunohistochemical studies investigating have been reported. suggest a loss of intestinal differentiation, exemplified high percentage CDX2 negativity. Our aim was further characterize the profile carcinoma, with particular emphasis on markers. Paraffin blocks from 16 cases 33 were retrieved, tissue microarrays constructed stained an panel including CDX2, CK7, CK20, p53, trefoil factor 3, chromogranin, synaptophysin, MLH-1, MUC-1, MUC-2, calretinin. A significantly higher proportion carcinomas, as opposed showed staining for MLH-1 transcription in accordance previous studies. present only 21% 60% (P = .02), whereas positive 19% carcinomas 55% .03). Interestingly, calretinin strongly 73% 12% < .0001). Evidence differentiation TFF-3 seen 67%, 60%, 53% respectively. 3 markers frequently many CDX2-negative cases. Medullary colon retains significant degree evidenced TFF-3. Calretinin, help colon.