At first glance, this is a very alarming case. However, careful inspection indicates that this mass is arising from the uterus, and thus the differential quickly narrows to a degenerating pedunculate fibroid or leiomyosarcoma.

This patient proceeded to surgery where they confirmed it arising from the lower uterine segment, with final pathology demonstrating a benign leiomyoma with gelatinous material (characteristic of myxoid degeneration).