Methylene blue: how to visualize the endometrium in uterine morcellation material

The aim of the study was to evaluate whether the preoperative intrauterine injection of methylene blue could help in visualizing the endometrium of uterine morcellation specimens. A total of 48 laparoscopic subtotal hysterectomies using the uterine morcellation technique were used for the study. In 19 of these cases, a preoperative intrauterine administration of methylene blue had been performed (study group). The total number of slides for each group, without and with methylene blue, was counted. Moreover, the number of slides comprising endometrial tissue was evaluated. The number of sections included in the control group to adequately assess the endometrium ranged from 6 to 95 (mean 27.24±4.01), whereas the respective number for the study group ranged from 4 to 10 (mean 7.21±0.44). The efficacy of recognizing adequate endometrial tissue (defined by the percentage of slides with adequate endometrial tissue over the overall slides requested to evaluate complete uterine histology) was significantly higher in the study group compared with that in the control group (67.05%±2.36% vs. 17.46%±2.66%, respectively; P<10(-3)). The preoperative intrauterine methylene blue administration when programming a uterine morcellation is an easy, cheap, harmless, and quick procedure that has many advantages. It reduces the time of gross handling and the number of tissue blocks submitted for examination without harming the morphologic appearance of the endometrial tissue. Moreover, it helps pathologists in identifying areas with endometrial pathology that would have probably escaped from attention in conventionally handled material.