title: Clinicopathologic study of 62 acinar cell carcinomas of the pancreas: insights into the morphology and immunophenotype and search for prognostic markers.
abstract: Acinar cell carcinoma (ACC) of the pancreas is a very rare tumor that has various morphologic features, which may give rise to diagnostic difficulties. Because of its rarity, many clinicopathologic characteristics remain to be further elucidated, and prognostic factors are yet to be well established. With the aim of better characterizing this carcinoma and searching for prognostic indicators, we collected 62 ACCs and investigated the following parameters: site, size, local infiltration, node and distant metastases, architectural pattern, nuclear atypia, presence of necrosis, lymphovascular and perineural invasion, proliferation, BCL10, trypsin, carboxyl ester lipase, amylase, lipase, PDX1, cytokeratin 19 (CK19), CK7, p53, and β-catenin expression. Twelve cases showing >30% of endocrine cells were reclassified as mixed acinar-neuroendocrine carcinomas, whereas 1 tumor was reclassified as a mixed ductal-acinar carcinoma and was excluded from the statistical prognostic evaluations. BCL10 and trypsin were the most reliable immunohistochemical markers, whereas amylase and lipase were not. Surgery was statistically correlated with a better prognosis (P=0.0008). Among resected tumors there was no difference in survival between ACCs and mixed acinar-neuroendocrine carcinomas, and factors that significantly correlated with poor prognosis were size >6.5 cm (P=0.004), lymph node (P=0.0039) and distant (P=0.008) metastases, and UICC stage (P=0.009). Stage was the only independent prognostic factor at multivariable analysis, and the best prognostic discrimination was observed on grouping together stages I and II and grouping together stages III and IV, suggesting a simplification of the UICC staging for such cancers. In addition, vascular and perineural invasion and CK19 and p53 expression showed a trend for poor prognosis, not reaching statistical significance.
authors.affiliation: Department of Pathology, Ospedale di Circolo, 21100 Varese, Italy. stefano.larosa@ospedale.varese.it
authors.forename: Stefano
authors.initials: S
authors.lastname: La Rosa
authors.forename: Volkan
authors.initials: V
authors.lastname: Adsay
authors.forename: Luca
authors.initials: L
authors.lastname: Albarello
authors.forename: Sofia
authors.initials: S
authors.lastname: Asioli
authors.forename: Selenia
authors.initials: S
authors.lastname: Casnedi
authors.forename: Francesca
authors.initials: F
authors.lastname: Franzi
authors.forename: Alessandro
authors.initials: A
authors.lastname: Marando
authors.forename: Kenji
authors.initials: K
authors.lastname: Notohara
authors.forename: Fausto
authors.initials: F
authors.lastname: Sessa
authors.forename: Alessandro
authors.initials: A
authors.lastname: Vanoli
authors.forename: Lizhi
authors.initials: L
authors.lastname: Zhang
authors.forename: Carlo
authors.initials: C
authors.lastname: Capella
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D018267:Carcinoma, Acinar Cell / Q000737:chemistry / Q000175:diagnosis* / Q000276:immunology / Q000401:mortality / Q000556:secondary / Q000601:surgery; D049109:Cell Proliferation; D005060:Europe; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping; D007564:Japan; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009336:Necrosis; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000276:immunology / Q000401:mortality / Q000473:pathology / Q000601:surgery; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors; D047368:Tumor Burden; D014481:United States
chemical_list: D014408:Biomarkers, Tumor