title: The morphologic and immunohistochemical spectrum of papillary renal cell carcinoma: study including 132 cases with pure type 1 and type 2 morphology as well as tumors with overlapping features.
abstract: Papillary renal cell carcinomas (pRCC) are classically divided into type 1 and 2 tumors. However, many cases do not fulfill all the criteria for either type. We describe the clinical, morphologic, and immunohistochemical (IHC) features of 132 pRCCs to better characterize the frequency and nature of tumors with overlapping features. Cases were reviewed and classified; IHC evaluation of CK7, EMA, TopoIIα, napsin A, and AMACR was performed on 95 cases. The frequencies of type 1, type 2, and "overlapping" pRCC were 25%, 28%, and 47%, respectively. The 2 categories of "overlapping" tumors were: (1) cases with bland cuboidal cells but no basophilic cytoplasm (type A); and (2) cases with predominantly type 1 histology admixed with areas showing prominent nucleoli (type B). The pathologic stage of "overlapping" cases showed concordance with type 1 tumors. Using the 2 discriminatory markers (CK7, EMA), "type A" cases were similar to type 1. Although the high-nuclear grade areas of "type B" tumors showed some staining differences from their low-nuclear grade counterpart, their IHC profile was closer to type 1. Single nucleotide polymorphism array results, although preliminary and restricted to only 9 cases (3 with overlapping features), also seemed to confirm those findings. In conclusion, we demonstrate that variations in cytoplasmic quality and/or presence of high-grade nuclei in tumors otherwise displaying features of type 1 pRCCs are similar in stage and IHC profile those with classic type 1 histology, suggesting that their spectrum might be wider than originally described.
authors.affiliation: Departments of *Pathology †Human Genetics §Urology, McGill University ‡McGill University and Genome Quebec Innovation Centre ∥Pathologie et Biologie Cellulaire, Université de Montréal, QC, Canada.
authors.forename: Myriam
authors.initials: M
authors.lastname: Chevarie-Davis
authors.forename: Yasser
authors.initials: Y
authors.lastname: Riazalhosseini
authors.forename: Madeleine
authors.initials: M
authors.lastname: Arseneault
authors.forename: Armen
authors.initials: A
authors.lastname: Aprikian
authors.forename: Wassim
authors.initials: W
authors.lastname: Kassouf
authors.forename: Simon
authors.initials: S
authors.lastname: Tanguay
authors.forename: Mathieu
authors.initials: M
authors.lastname: Latour
authors.forename: Fadi
authors.initials: F
authors.lastname: Brimo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000235:genetics; D001706:Biopsy; D002291:Carcinoma, Papillary / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000473:pathology*; D002292:Carcinoma, Renal Cell / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000473:pathology*; D002467:Cell Nucleus / Q000473:pathology; D048430:Cell Shape; D003937:Diagnosis, Differential; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D020641:Polymorphism, Single Nucleotide; D011237:Predictive Value of Tests; D011792:Quebec; D009626:Terminology as Topic
chemical_list: D014408:Biomarkers, Tumor