Clear cell carcinoma arising from a uterus-like mass

Area of Science:

• Gynecologic Oncology
• Pathology
• Reproductive Medicine

Background:

• A uterus-like mass is a rare extrauterine condition characterized by a cavity lined by endometrial tissue and a smooth muscle layer.
• Its histogenesis remains unclear, posing diagnostic and therapeutic challenges.

Observation:

• A 67-year-old nulliparous woman with a 14-year history of an ovarian endometriotic cyst was found to have a retroperitoneal mass.
• Imaging revealed an enlarged cystic mass with a thickened, irregular wall, raising suspicion for malignancy.
• Surgical excision identified a distinct 8 cm retroperitoneal mass with features resembling uterine myometrium.

Findings:

• Microscopic examination confirmed the presence of endometrial tissue within the cyst.
• The endometrial lining was diffusely infiltrated by clear cell carcinoma.
• The mass was separate from the normal uterus and right ovary.

Implications:

• This case demonstrates that clear cell carcinoma can arise from a uterus-like mass.
• The pathway of carcinogenesis may be similar to that observed in endometriosis-related ovarian neoplasms.
• Further research into the histogenesis and malignant potential of uterus-like masses is warranted.