Vascular “Pseudo Invasion” in Laparoscopic Hysterectomy Specimens: A Diagnostic Pitfall

Abstract

Total laparoscopic hysterectomy has been shown to be an equally effective and safe technique when compared with conventional abdominal surgery for endometrial carcinoma. The procedure, as performed at our institution, involves the use of a uterine balloon manipulator (RUMI manipulator and Koh Colpotomizer system) for optimal surgical control. The fallopian tubes are cauterized to prevent transtubal spread of the tumor. The balloon manipulator thus creates a positive closed pressure system within the uterine cavity. After observing extensive displacement of tumor into small and large blood vessels in 1 case of grade 1, stage 1b endometrial carcinoma, we reviewed slides from 37 hysterectomy specimens (7 for endometrial carcinoma or atypical hyperplasia and 30 for benign conditions) performed laparoscopically between August 2004 and March 2006 at Emory University and Crawford Long Hospitals. We reviewed all slides for the presence or absence of endometrial tumor/tissue in vascular spaces. Patients with endometrial carcinoma/atypical complex hyperplasia included 6 FIGO grade I endometrioid carcinomas (3 stages 1A; 3 stages 1B) and 1 patient with atypical complex hyperplasia. Tumor within blood vessels was noted in 5 of 7 (71%) cases. In 3 cases, including the case of atypical complex hyperplasia, the number of vessels containing tumor were too numerous to count small and large caliber blood vessels. In the remainder, 1 case had 2 small vessels involved and in the other 7 small vessels showed tumor within vascular lumina. Benign endometrial glands and stromal tissue were noted within vascular spaces in 4 of 30 (13%) hysterectomy specimens removed for benign conditions. We describe a hitherto unreported artifact of vascular pseudo invasion in hysterectomy specimens obtained using the technique of total laparoscopic abdominal hysterectomy. We postulate that the creation of a closed pressure system generated as part of the operative technique is likely responsible for this phenomenon. Pathologists need to be aware of this artifact to avoid misinterpretation of vascular invasion in these cases with its associated therapeutic and prognostic implications.

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

“…In contrast to the two previously published studies, which addressed vascular space involvement by endometrial carcinoma in total laparoscopic hysterectomies, 7,8 this study did not find a significant difference in the rate of vascular space involvement between total laparoscopic hysterectomy and total abdominal hysterectomy. Nevertheless, there was a trend towards a higher frequency of vascular space involvement in the total laparoscopic hysterectomy group and the lack of a strong correlation can be related to a number of issues.…”

“…Thirty-seven laparoscopic hysterectomies for benign (30) and neoplastic (7) conditions, including six grade 1 endometrioid cancers and one atypical complex hyperplasia, were originally examined. 7 The authors found tumor in blood vessels in 71% of the malignant total laparoscopic hysterectomies and benign glands and stroma in vascular spaces of 13% of benign cases. They concluded that total laparoscopic hysterectomy is associated with high rates of vascular pseudoinvasion, which is presumably caused by the increased intrauterine pressure created by the intrauterine manipulator.…”

Efficacy and safety of uterine manipulators in laparoscopic surgery: a review

“…In both cervical and endometrial malignancies, clinico-pathological parameters such as infiltration depth and lymphovascular space invasion (LVSI) may be influenced when a manipulator is used [27][28][29][30][31]. However, it is hypothesised that other factors such as artefacts and tissue handling contributed to these findings.…”

Recent Developments in Surgical Pathology of the Uterine Corpus

“…One possible explanation for this phenomenon can be described as vacuum effect in which the lymphovascular spaces in the endometrium collapse owing to positive pressure in the uterine cavity; this makes the myometrial vasculature accessible to dislodged endometrial glands and stroma. 88 Others propose that LVPI is a grossing artifact, arguing that displacement of endometrial glands and stroma is a result of manipulation of the specimen in the gross room and is more likely to occur in exophytic tumors. 87,89 However, it should also be noted that there can be significant interobserver variability in assessing lymphovascular space invasion.…”