Clinicopathologic significance of nuclear grooves and inclusions in renal cell carcinoma: image database construction and quantitative scoring.
BACKGROUND
Nuclear grooves and inclusions are major features of cancer. However, the nuclear irregularities in renal cell carcinoma (RCC) have not yet been well characterized.


OBJECTIVE
To determine the clinicopathologic significance of nuclear grooves and inclusions in RCC.


METHODS
The frequencies or scores of nuclear grooves and inclusions were compared with the histologic subtype, nuclear grade, and TNM stage, as well as overall survival of RCC patients. For objective counting of nuclear irregularities, a relational image database was constructed and used for quantitative assessment.


RESULTS
Nuclear grooves and inclusions were seen in 96% and 65% of 110 RCC cases, respectively. The intranuclear inclusions were found more frequently in chromophobe and papillary types than in clear cell carcinoma (P < .001). The nuclear scores, the sum of grooves or inclusions per 5000 tumor cells, were highly related to the histologic subtype (P < .001). Clear cell RCCs with high inclusion scores (2 or more) were correlated with poorer overall survival in comparison to clear cell carcinomas with low inclusion scores (P = .04). The groove scores were highly associated with Fuhrman grade (P = .003) but not with overall survival of clear cell RCC patients (P = .65). In multivariate analysis, higher inclusion scores and advanced tumor stages (III/IV) were correlated with worse outcomes of clear cell RCC.


CONCLUSIONS
Nuclear grooves and inclusions are histologic components of RCCs, especially chromophobe and papillary carcinomas. Furthermore, nuclear inclusions might be an independent prognostic factor for clear cell RCC.
Department of Pathology and Bioinformatics Interest Group, Korea University Ansan Hospital, Ansan, Republic of Korea.
Ju-Han
JH
Lee
Eun Mee
EM
Han
Zhen-Hua
ZH
Lin
Zheng-Sheng
ZS
Wu
Eung-Seok
ES
Lee
Young-Sik
YS
Kim
D000328:Adult; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000401:mortality / Q000473:pathology*; D002467:Cell Nucleus / Q000473:pathology; D016208:Databases, Factual; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D002479:Inclusion Bodies / Q000473:pathology*; D053208:Kaplan-Meier Estimate; D007680:Kidney Neoplasms / Q000401:mortality / Q000473:pathology*; D008297:Male; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012372:ROC Curve