title: A Subset of Sinonasal Non-Intestinal Type Adenocarcinomas are Truly Seromucinous Adenocarcinomas: A Morphologic and Immunophenotypic Assessment and Description of a Novel Pitfall.
abstract: While sinonasal intestinal type adenocarcinoma (ITAC) is defined by an intestinal phenotype, non-intestinal type adenocarcinoma (non-ITAC) is traditionally viewed as a diagnosis of exclusion, despite previous implication of a seromucinous phenotype and similarity to sinonasal seromucinous hamartomas (SSH). We performed a comparison of clinicopathologic and immunophenotypic features of ITAC, non-ITAC and SSH using traditional discriminatory markers and new markers of seromucinous differentiation. Twenty-three non-ITAC, 17 ITAC, and 5 SSH were retrieved (1987-2014). As expected, ITAC occurred predominantly in the nasal cavity in elderly patients (mean age 65 years) with a striking male predilection (15:2). Regardless of grade/subtype, all ITAC were invariably CK20 and CDX2 positive, and many (11/15) showed some CK7 positivity. Non-ITAC occurred in younger individuals (mean age 51 years) with a slight female predilection (male to female ratio: 10:13) and showed diverse morphologic patterns and grades, some with morphologic similarity to SSH. SSH occurred in younger individuals (mean age 33 years). Non-ITAC and SSH were invariably CK7 positive and CK20 negative, however, 4/22 non-ITAC and 2/5 SSH showed squamoid morular metaplasia that aberrantly expressed CDX2 and co-expressed nuclear β-catenin. Markers of seromucinous differentiation (S100, DOG1, and SOX10) were essentially absent in ITAC, but present to varying degrees in the majority of non-ITAC and all SSH. Thus, the term 'seromucinous adenocarcinoma' is the more appropriate designation for non-ITAC. Squamoid morules in non-ITAC and SSH may be an immunophenotypic pitfall given the aberrant CDX2 expression.
authors.affiliation: Department of Pathology and Laboratory Medicine, The Ottawa Hospital, University of Ottawa, Ottawa, ON, K1H 8L6, Canada.
authors.forename: Bibianna
authors.initials: B
authors.lastname: Purgina
authors.affiliation: Department of Pathology, Presbyterian-Shadyside Hospital, University of Pittsburgh Medical Center, Pittsburgh, PA, 15232, USA.
authors.forename: Jassem M
authors.initials: JM
authors.lastname: Bastaki
authors.affiliation: Department of Otolaryngology, Presbyterian-Shadyside Hospital, University of Pittsburgh Medical Center, Pittsburgh, PA, 15232, USA.|Section of Otolaryngology, VA Pittsburgh Health System, Pittsburgh, PA, 15240, USA.
authors.forename: Umamaheswar
authors.initials: U
authors.lastname: Duvvuri
authors.affiliation: Department of Pathology, Presbyterian-Shadyside Hospital, University of Pittsburgh Medical Center, Pittsburgh, PA, 15232, USA. seethalarr@upmc.edu.|Department of Otolaryngology, Presbyterian-Shadyside Hospital, University of Pittsburgh Medical Center, Pittsburgh, PA, 15232, USA. seethalarr@upmc.edu.|A614.X Presbyterian University Hospital, 200 Lothrop St, Pittsburgh, PA, 15213, USA. seethalarr@upmc.edu.
authors.forename: Raja R
authors.initials: RR
authors.lastname: Seethala
mesh_terms: D000230:Adenocarcinoma / Q000145:classification* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping; D008297:Male; D008875:Middle Aged; D009669:Nose Neoplasms / Q000145:classification* / Q000473:pathology; D010255:Paranasal Sinus Neoplasms / Q000145:classification* / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor
keywords: Adenocarcinoma; DOG1; Non-intestinal; SOX10; Seromucinous