Periacinar retraction artifact of the prostate.

Retraction artifacts are well known phenomenon in diagnostic surgical pathology for a long time but they were usually considered as artificially produced tissue alteration. Some recent studies of retraction artifact in different tumors have focused on its diagnostic and/or prognostic role. Their presence in prostatic carcinoma may be used in diagnostic and prognostic purposes. Peritumoral retraction artefacts in prostatic carcinoma are more pronounced and more common around neoplastic glands compared to benign glands, gland with prostatic intraepithelial neoplasia and postatrophic hyperplasia that is the one of the most common mimickers of prostatic carcinoma. In addition, the presence of extensive retraction artifact in prostatic carcinomas is clearly associated with tumor features that indicate a more aggressive tumor phenotype and with shorter biochemical recurrence-free survival. Studies at the molecular level demonstrate that retraction artifact may be attributed to molecules produced by reactive cancer stroma. The origin of retraction artifact in tumor specimens is unknown but they are probably the consequence of lack of basal cells and /or stromal changes but not simply artifacts due to laboratory procedures.