Minimal or no residual prostatic adenocarcinoma on radical prostatectomy: a 5-year experience with "vanishing carcinoma phenomenon".
BACKGROUND
"Vanishing carcinoma phenomenon" (VC) has been defined as the finding of minute or no cancer on radical prostatectomy specimens after a positive biopsy.


OBJECTIVE
To discuss our experience with VC and to recommend guidelines for its detection.


METHODS
One thousand seven hundred forty-one radical prostatectomy specimens (2004-2009) processed by whole-mount section procedure yielded 21 (1.2%) cases with VC and 6 (0.34%) cases with minimal carcinoma (≤ 2 mm) in the radical prostatectomy specimen. To find the eluding carcinoma in VC cases or more carcinoma in minimal carcinoma cases, the following was done: 3 levels of all the paraffin blocks were obtained; if negative, the paraffin blocks were melted, the tissue was flipped, and 3 levels were prepared. The tumor bank frozen tissue was also processed for routine examination.


RESULTS
Three deeper levels in the radical prostatectomy specimen of 21 VC cases failed to show malignancy; however, the flipping and recutting of the tissue yielded a focus of carcinoma (1-5 mm) in 16 of 21 cases and in 3 of 16 cases in the saved frozen tissue. In 1 of the 6 cases with minimal carcinoma, subsequent recuts of the flipped tissue displayed carcinoma (2 foci of tumor, <1 mm each).


CONCLUSIONS
In VC we recommend: embed and process any remaining prostatic tissue including any saved fresh-frozen tissue; obtain 3 levels of each paraffin block; if results are negative, melt and flip the tissue and obtain 3 more levels. Following the above guidelines, a hidden carcinoma may be detected in the majority of the cases of VC.
Department of Pathology, The Methodist Hospital, 6565 Fannin St, Houston, TX 77030, USA. okosarac@tmhs.org
Ognjen
O
Kosarac
Qihui Jim
QJ
Zhai
Steven
S
Shen
Hidehiro
H
Takei
Jae Y
JY
Ro
Alberto G
AG
Ayala
D000230:Adenocarcinoma / Q000473:pathology / Q000601:surgery*; D000368:Aged; D016208:Databases, Factual; D006801:Humans; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000473:pathology / Q000601:surgery*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000473:pathology / Q000601:surgery*