The impact of complete embedding of remaining tissue in gynecological lymph node dissection specimen in surgical pathology on lymph node yield: is it clinically relevant?

The assessment of nodal metastases in gynecological surgical specimen is an important staging parameter, directing further therapeutic procedures. Since the number of lymph nodes (LNs) removed is seen as an indicator of surgical and pathological quality, the demand for higher lymph node (LN) counts is raising. The goal of this prospective study was the comparison between lymph node counts of macroscopically detectable LNs and the LN yield by complete embedding and proceeding of all submitted LN-containing tissue in the pathology laboratory. One hundred six cases of cervical, uterine, or ovarian cancer, treated in three different hospitals within 3 years, were analyzed. All tissue submitted to the pathology from the surgically performed LN dissections was completely dissected and embedded in the institute of pathology. Subsequently, the amount of LN of all macroscopically detectable nodes was compared to the final histologically reached numbers of LN. Furthermore the histologically visible area of the LNs and their metastases was analyzed to assess the relation of LN numbers to the whole examined LN area. Complete embedding raises the average number of LN counted by 3 to 7 but did only minimally increase the LN area for microscopical examination by about 5% due to the small area of the additional LNs in the remaining fat tissue. The staging was in no case altered by complete embedding, even when additional nodal metastases were detected in the remaining fat tissue, since this was only seen in cases which had already metastatic nodes. Complete embedding of LN-containing tissue did not provide relevant additional staging information and seems therefore unnecessarily laborious, careful pathological work-up assumed.