Histological step sectioning of pelvic lymph nodes increases the number of identified lymph node metastases

Pathological examinations of lymph nodes (LN) in prostate cancer patients are handled differently at various institutions. The objective of this study is to provide means to improve the guidelines by examining the impact of step sectioning on LN status in patients with intermediate and high-risk prostate cancer. Two hundred ten patients who awaited curative indented therapy were included. We first performed a standard pathological examination of the LN, followed by an extended pathological examination of the patients who were LN negative in the standard examination. The extended pathological examination included a 100-mu m-deep haematoxylin and eosin (HE) section followed by a slide stained with cytokeratin AE1/AE3 and then by four HE sections at 0.5-mm intervals. The standard pathological examination detected 41 patients with LN metastasis. The remaining 169 patients had 1,185 HE sections made at the standard examination, whereas the extended examination gave additional 7,110 slides and detected 5 additional patients with LN metastasis. In all, 1,158 LN were removed. The additional LN metastases were smaller than the LN metastases found at the standard examination, mean 1.2 mm vs. 7.8 mm. Our results indicate that an extended pathological examination of LN will improve the staging of intermediate- and high-risk prostate cancer patients; however, we acknowledge that it is both costly and time consuming. We do not recommend the use of cytokeratin staining in routine staining because the immunohistochemistry did not reveal new or further information. A detailed guideline on how to handle the LN specimens at the pathological department is needed.