Histopathologic analysis of peritumoral pseudocapsule and surgical margin status after tumor enucleation for renal cell carcinoma.
BACKGROUND
The oncologic safety of blunt tumor enucleation (TE) of renal cell carcinoma (RCC) depends on the presence of a continuous pseudocapsule (PS) around the tumor and on the possibility of obtaining negative surgical margins (SMs).


OBJECTIVE
To investigate the PS and SMs after TE to define the real need to take a rim of healthy parenchyma around the tumor to avoid the risk of positive SMs. The risk of PS invasion related to other clinical and pathologic variables was also evaluated.


METHODS
Between September 2006 and December 2007, data were gathered prospectively from 187 consecutive patients who had kidney surgery. Overall, 90 consecutive patients who had TE for RCC were eligible for the study. All specimens were evaluated using an image analyzer by a dedicated uropathologist.


METHODS
TE was done by blunt dissection using the natural cleavage plane between the tumor and the normal parenchyma.


METHODS
PS, SM, and routinely available clinical and pathologic variables were recorded.


CONCLUSIONS
In 60 RCC tumors (67%) the PS was intact and free from invasion (PS-) while in 30 (33%) there were signs of penetration within its layers, with or without invasion beyond it. Indeed, 26.6% had PS that had been penetrated on the parenchymal side and 6.6% had penetration on the perirenal fat tissue side. The odds of having PS penetration increased significantly with an increase in clinical tumor size. PS penetration was also significantly associated with pathologic tumor dimensions and grade. In all cases the SMs were negative after TE. The present patients, followed for >2 yr, will enable us to correlate the risk of local recurrence with PS status.


CONCLUSIONS
The risk of PS penetration is associated with clinical and pathologic tumor dimensions and grade. If there is PS invasion into normal parenchyma, the presence of a thin layer of tissue allows for negative SM even if a TE is performed.
Minervini
Andrea
A
Department of Urology, University of Florence, Careggi Hospital, Florence, Italy. andreamine@libero.it
di Cristofano
Claudio
C
Lapini
Alberto
A
Marchi
Marco
M
Lanzi
Federico
F
Giubilei
Gianluca
G
Tosi
Nicola
N
Tuccio
Agostino
A
Mancini
Massimiliano
M
della Rocca
Carlo
C
Serni
Sergio
S
Bevilacqua
Generoso
G
Carini
Marco
M
D000368:Aged; D001707:Biopsy, Needle; D002292:Carcinoma, Renal Cell / Q000473:pathology* / Q000601:surgery*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000473:pathology* / Q000601:surgery*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods; D009361:Neoplasm Invasiveness / Q000473:pathology*; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D009367:Neoplasm Staging; D009360:Neoplastic Cells, Circulating / Q000473:pathology; D009392:Nephrectomy / Q000379:methods*; D016017:Odds Ratio; D011336:Probability; D011379:Prognosis; D011446:Prospective Studies; D016896:Treatment Outcome