Path. Res. Pract. 191, 836 - 837 (1995)
Working Standards in Prostatic Intraepithelial Neoplasia and Atypical Adenomatous Hyperplasia F. Algaba, J.I. Epstein, G. Fabus, B. Helpap, R.B. Nagle and
Section of Pathology, Fundaci6 Puigvert, Universitat Aut6noma de Barcelona, Barcelona, Spain
SUMMARY All participants agreed with the use of the terms low and high grade PIN, without treatment in the case of an isolated PIN lesion. The term, definitions and biology of atypical adenomatous hyperplasia (AAH) was discussed without reaching a consent among American and European participants. As a compromise, the designation of AAH-Adenosis was accepted as a working formulation that needs further research.
Prostatic Intraepithelial Neoplasia (PIN) All participants agreed with the use of the term prostatic intraepithelial neoplasia (PIN), and jointly decided not to use the term intraductal dysplasia. Consensus was also reached on classifying PIN as low grade and high grade. This will allow greater reproducibility of diagnosis, allowing recognition of a single gland with these changes. There were two major points of discussion. The first point was how to inform the urologist of the finding of PIN, and the second was how to evaluate microinvasion. All participants agreed that urologists should be informed about high grade PIN, whereas reporting of low grade PIN was not essential. We do not recommend treatment in patients presenting only with high grade PIN. The best course of action is to repeat the biopsy, especially in patients with elevated serum PSA. How should one interpret the presence of stromal microinvasion adjacent to PIN? No agreement was reached regarding this, although it was agreed that a new biopsy would be advisable. 0344-0338/95/0191-0836$3.50/0
Atypical Adenomatous Hyperplasia (AAH), Adenosis Despite the fact that all the participants in the Working Group agreed with the criteria for the diagnosis of this lesion, no agreement was reached regarding nomenclature. Some participants from the USA regarded the introduction of the term "atypical" as too agressive, possibly inducing therapeutic intervention, whereas the European participants felt that this risk did not exist. The discrepancy in terminology was also due to the belief on the part of USA participants that AAH is not a premalignant lesion, whereas participants from Europe believe that it might be the precursor of well differentiated carcinoma in the transition zone. To resolve this subject, a compromise was reached to utilize the term AAH (only the initials) followed by Adenosis. Among the criteria discussed for the delimitation of the morphological entities of AAH-Adenosis, the utility of high molecular weight cytokeratin (HMC) was evaluated. It was agreed that there is irregular expression of © 1995 by Gustav Fischer Verlag, Stuttgart
Working Standards in Atypical Adenomatous Hyperplasia· 837
HMC in samples obtained by transurethral resection or open surgery, while it is much better in core biopsies. Because of this, it was concluded that in AAH-Adenosis, there can be an irregular expression of HMC; however, if less than 10% of the basal cells are without HMC, it can be considered carcinoma.
Agreement was not reached regarding interpretation of small acinar foci with cells containing prominent nucleoli. For some participants, this was simply a variation of AAH-Adenosis and, for others, this was a small focus of malignant transformation of AAH-Adenosis.
Received March 1, 1995 . Accepted June 10, 1995
Key words: Prostatic Intraepithelial Neoplasia (PIN), Delimitation of - PIN, consensus of - Atypical Adenomatous Hyperplasia (AAH), Delimitation of - AAH, consensus of Ferran Algaba, Section of Pathology, Fundaci6 Puigvert, Universitat Aut6noma de Barcelona, Barcelona, Spain