Vascular "pseudo invasion" in laparoscopic hysterectomy specimens: a diagnostic pitfall

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.