Abstract
BACKGROUND: Retroperitoneal leiomyoma is a rare benign tumor. Retroperitoneal leiomyomas located in the latissimus uterine ligament are even rarer. Retroperitoneal leiomyomas have similar characteristics to uterine leiomyomas in terms of tissue, which results in confusion during diagnosis. CASE SUMMARY: A 47-year-old female with 3 years of pain in the right lower quadrant and discovery of a pelvic mass 13 d ago underwent open abdominal exploration. In the right broad ligament, a solid mass with well circumscribed boundaries, approximately 15 cm × 10 cm × 10 cm in size was bluntly peeled off. The pathological result was a spindle cell tumor, morphologically considered to originate from smooth muscle. Immunohistochemical results supported a deep soft tissue leiomyoma. CONCLUSION: Retroperitoneal leiomyoma is a rare benign tumor, and surgical treatment can have a good therapeutic effect.