title: Colonic carcinoma with a pancreatic acinar cell differentiation. A case report.
abstract: A case of a colonic carcinoma showing a pancreatic acinar cell differentiation is described for the first time. A 65-year-old woman underwent surgical resection for an ulcerated protruding tumour of 4 x 2.5 cm in size on the anterior wall of the sigmoid colon. Histologically, tumour cells were organized in acinar structures resembling pancreatic acini and in solid nests and ribbons or diffusely infiltrated as poorly cohesive cells. Lymph nodes and femur metastases displayed the same histological features. The ultrastructural analysis of the primary tumour indicated the presence of zymogen-like granules in the cytoplasm of tumour cells. Immunohistochemically, both acinar and diffuse patterns of growth showed an intense staining for trypsin, chymotrypsin and BCL10 and a weaker immunoreactivity for lipase and carboxyl ester hydrolase. Most tumour cells were cytokeratin 20, CDX2 and p53 positive; whereas, mucin (MUC)2 immunoreactivity was observed only in the signet ring cells present in the diffuse pattern and chromogranin A in rare isolated tumour cells. No immunoreactivity was observed for cytokeratin 7, MUC1, MUC5AC, pancreatic amylase or PDX1. There was no evidence of a pancreatic acinar cell carcinoma or of heterotopic pancreatic tissue. A colonic origin ought to be suspected when a metastatic carcinoma of unknown primary shows an acinar differentiation.
authors.affiliation: Department of Pathology, Ospedale di Circolo, viale Borri 57, 21100, Varese, Italy. annamaria.chiaravalli@tin.it
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Chiaravalli
authors.forename: Giovanna
authors.initials: G
authors.lastname: Finzi
authors.forename: Valentina
authors.initials: V
authors.lastname: Bertolini
authors.forename: Stefano
authors.initials: S
authors.lastname: La Rosa
authors.forename: Carlo
authors.initials: C
authors.lastname: Capella
mesh_terms: D000368:Aged; D000071616:CDX2 Transcription Factor; D018267:Carcinoma, Acinar Cell / Q000473:pathology*; D002454:Cell Differentiation; D003110:Colonic Neoplasms / Q000473:pathology*; D017809:Fatal Outcome; D005260:Female; D018398:Homeodomain Proteins / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D053554:Keratin-20 / Q000378:metabolism; D008207:Lymphatic Metastasis; D010190:Pancreatic Neoplasms / Q000473:pathology*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D000071616:CDX2 Transcription Factor; C491270:CDX2 protein, human; D018398:Homeodomain Proteins; D053554:Keratin-20; D016159:Tumor Suppressor Protein p53