Intraoperative examination for suspected prostatic carcinoma: frozen sections in "marginal" (cadaveric) transplant donors.

Elderly patients are a potential source of additional organ supply for transplantation. Unfortunately, with increasing age, the chance is greater that an apparently healthy aged man will be carrying a silent prostatic carcinoma. Therefore, in order to maximize safety, intraoperatory evaluation of the prostatic gland may be required to rule out adenocarcinoma. We evaluated 14 prostatic tissue specimens obtained from "marginal" donors and examined by intraoperatory frozen sections. These were positive for carcinoma in three cases and negative in 11. Examination of permanent sections from snap-frozen tissue revealed three additional cases that were unrecognized on the initial frozen sections. The inaccuracy of the method could be explained by the difficulty, caused by freezing, of discriminating benign from malignant gland and by technical artifacts. Snap-freezing artifacts also compromised the evaluation of tumor invasion into the extraprostatic fat in 2 cases. Because of the architectural distortion, frozen sections were also ineffective in the recognition of Gleason pattern in all cases. Examination of prostatic frozen sections may be useful if the pathologist is asked to recognize only larger tumors. The estimation of small volume tumors, extracapsular extension, as well as Gleason pattern assessment suffers from an irreducible bias.