Morphologic typing of papillary renal cell carcinoma: comparison of growth kinetics and patient survival in 66 cases.
Whereas papillary renal cell carcinoma is now established as a subtype of renal cell neoplasia, division of these tumors into 2 distinctive morphotypes has been proposed. Type 1 tumors have cells with scanty pale cytoplasm arranged in a single layer on the basement membrane of papillary cores. In these tumors, psammoma bodies and foamy macrophages are frequently seen, and the tumors frequently express cytokeratin 7. Type 2 tumor cells have pseudostratified nuclei and usually have voluminous eosinophilic cytoplasm. Recent studies have supported this subclassification of papillary renal cell carcinoma by demonstrating differing genotypes for type 1 and 2 tumors. To further study the subclassification of papillary renal carcinoma, we compared clinical features, nuclear grade, stage, tumor growth kinetics, and survival in a series of 50 type 1 and 16 type 2 papillary renal cell carcinomas. Comparison of patient age at presentation, sex, and primary tumor size shows no significant difference between the 2 tumor types. Type 1 tumors were of significantly lower Fuhrman grade (P =.0001) and higher Robson stage (P =.009) than type 2 tumors. There was no significant difference when tumors were staged according to the TNM classification. Assessment of tumor growth kinetics showed significantly different mean silver-staining nucleolar organizer region (AgNOR) scores and Ki-67 indices (AgNOR type 1, 3.83, type 2, 7.24, P =.0001; Ki-67 type 1, 3.17%, type 2, 6.01%, P =.0002). Multivariate analysis showed tumor type (P =.03), presence of metastases (P =.04), AgNOR score (P =.001), and Ki-67 index (P =.03) to be independently associated with survival. These results provide evidence of the clinical utility of dividing papillary renal cell carcinomas into 2 types according to histologic characteristics.
Delahunt
B
B
Department of Pathology and Molecular Medicine, Wellington School of Medicine, University of Otago, Wellington, New Zealand.
Eble
J N
JN
McCredie
M R
MR
Bethwaite
P B
PB
Stewart
J H
JH
Bilous
A M
AM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002291:Carcinoma, Papillary / Q000145:classification / Q000401:mortality / Q000473:pathology*; D002292:Carcinoma, Renal Cell / Q000145:classification / Q000401:mortality / Q000473:pathology*; D002455:Cell Division; D002467:Cell Nucleus / Q000473:pathology; D003593:Cytoplasm / Q000473:pathology; D005260:Female; D006801:Humans; D053552:Keratin-7; D007633:Keratins / Q000032:analysis; D019394:Ki-67 Antigen / Q000032:analysis; D007680:Kidney Neoplasms / Q000145:classification / Q000401:mortality / Q000473:pathology*; D007700:Kinetics; D008264:Macrophages / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D009697:Nucleolus Organizer Region / Q000473:pathology; D016622:Silver Staining; D015996:Survival Rate
C507497:KRT7 protein, human; D053552:Keratin-7; D019394:Ki-67 Antigen; D007633:Keratins