Low-grade Endometrial Stromal Sarcoma Presenting as a Sigmoid Mass

Area of Science:

• Gynecologic Oncology
• Gastrointestinal Pathology
• Surgical Oncology

Background:

• Low-grade endometrial stromal sarcoma (LG-ESS) is a rare uterine neoplasm.
• LG-ESS typically recurs or metastasizes to pelvic or peritoneal sites, rarely involving the colon.

Observation:

• A 42-year-old female presented with constipation.
• EUS revealed a 5 cm hypoechoic sigmoid colon lesion.
• CT demonstrated a 7 cm pelvic mass and enlarged sigmoid mesocolon lymph nodes.

Findings:

• Biopsy confirmed LG-ESS.
• Anterior resection and bilateral salpingo-oophorectomy were performed.
• Endometrial nodules were also identified as LG-ESS.

Implications:

• This case represents LG-ESS presenting as a solitary sigmoid tumor without evident intrauterine lesions preoperatively.
• It underscores the importance of considering rare metastatic patterns in LG-ESS diagnosis.
• Further research into the metastatic behavior of LG-ESS is warranted.