Isolated retroperitoneal metastasis of cervical squamous cell carcinoma mimicking an adnexal mass: a rare case report with literature review

Abstract Background Isolated retroperitoneal cystic metastasis from cervical squamous cell carcinoma is exceedingly rare. When such a metastasis deposit is interpreted as a primary adnexal mass on preoperative imaging, it may pose a substantial diagnostic and therapeutic challenge—particularly in elderly patients, whose preoperative staging is often constrained by severe cervical atrophy. Case presentation A 70-year-old woman presented with intermittent vaginal bleeding. Preoperative workup, including pathological examination of a sloughed cervical vegetation and imaging, suggested a high-grade squamous intraepithelial lesion (at least carcinoma in situ) and a left adnexal cystic mass. Both ultrasound and pelvic magnetic resonance imaging (MRI) favored a diagnosis of a primary adnexal tumor. Intraoperatively, however, an isolated retroperitoneal cyst was identified. Frozen-section analysis confirmed metastatic squamous cell carcinoma. Given the patient’s advanced age and the intraoperative finding of disease consistent with at least International Federation of Gynecology and Obstetrics (FIGO) stage IIIC, the surgical team elected to perform total hysterectomy with bilateral salpingo-oophorectomy rather than radical hysterectomy with lymphadenectomy, followed by adjuvant chemoradiotherapy. Final pathology confirmed cervical non-keratinizing squamous cell carcinoma with lymphovascular invasion and an isolated retroperitoneal cystic metastasis. Conclusions This case highlights a critical diagnostic pitfall: retroperitoneal cystic metastases from cervical cancer may closely mimic primary adnexal neoplasms, particularly in elderly patients with severe cervical atrophy. When intraoperative findings confirm metastatic disease, a staged strategy consisting of total hysterectomy with bilateral salpingo-oophorectomy followed by adjuvant chemoradiotherapy may represent an individualized, evidence-informed approach consistent with the rationale of current guideline recommendations rather than serving as a universal standard. To our knowledge, this is the first reported case of an isolated retroperitoneal cystic metastasis from cervical carcinoma detected at initial diagnosis.