Evaluation of vascular space involvement in endometrial adenocarcinomas: laparoscopic vs abdominal hysterectomies

Recent reports have described 'vascular pseudoinvasion' in total laparoscopic hysterectomies with endometrial carcinoma. To better understand this phenomenon, we compared pathologic findings in these laparoscopic and total abdominal hysterectomies performed for uterine endometrioid adenocarcinoma. Reports from 58 robotically assisted laparoscopic and 39 abdominal hysterectomies with grade 1 or 2 endometrioid endometrial adenocarcinomas were reviewed for stage, depth of invasion, vascular space involvement, uterine weight, and lymph node metastases. In addition, attention was given to possible procedural artifacts, including vertical endomyometrial clefts, and inflammatory debris, benign endometrial glands, and disaggregated tumor cells in vascular spaces. All foci with vascular involvement were reviewed by three gynecologic pathologists. Nine of the 58 (16%) laparoscopic and 3 of the 39 (7%) abdominal hysterectomies contained vascular space involvement based on the original pathology reports (P-value=0.0833). No one histologic feature consistently distinguished laparoscopic from abdominal cases on blind review of the available cases. Disaggregated intravascular tumor cells were significantly associated with reported vascular involvement in both procedures (P-values<0.001 and 0.016), most of which were corroborated on review. Laparoscopic procedures tend to have a higher index of vascular involvement, which is associated with lower stage, fewer lymph node metastases, and less myometrial invasion; however, pathologists cannot consistently determine the procedure on histologic findings alone. Moreover, there is significant inter-observer variability in distinguishing true from artifactual vascular space involvement, even among pathologists at the same institution. The clinical significance of apparent true vascular space involvement seen adjacent to artifacts is unclear, as is the impact of laparoscopic hysterectomy on recurrence risk.