Difficult Diagnosis and Management of a Torsion-Associated Giant Paratubal Serous Borderline Mass: Unraveling a Rare Gynecologic Pathology-A Case Report.

BACKGROUND

Paratubal borderline tumors are exceptionally rare, particularly when presenting as giant adnexal masses complicated by torsion. Their clinical and radiological features often mimic ovarian lesions, and diagnosis is often only clarified intraoperatively or after definitive histological examination. This report highlights the diagnostic challenges and fertility-sparing management in a young woman with a giant paratubal serous borderline tumor.

CASE PRESENTATION: A 25-year-old nulliparous woman presented with acute abdominal pain and distension. Transabdominal ultrasonography by a senior obstetrician-gynecologist revealed a large left adnexal cystic mass (17 × 13 × 9 cm) with minimal vascular flow on Doppler. Laboratory results showed a normal complete blood count and serum CA-125 of 18.06 U/mL (reference <35 U/mL). No MRI was performed due to the emergency presentation with suspected torsion and limited availability. Exploratory laparotomy revealed a torsed giant left paratubal cyst; a fertility-sparing left salpingectomy was performed, preserving the ovary. Histopathology confirmed a serous borderline tumor arising from the paratubal region.

DISCUSSION: This case illustrates the diagnostic difficulty of distinguishing paratubal from ovarian tumors, particularly in emergency torsion. MRI, frozen section, and extended tumor markers may aid diagnosis but are often unavailable in resource-limited settings. Fertility-sparing surgery remains a feasible option in carefully selected young patients, supported by literature showing favorable outcomes.

CONCLUSION

Giant paratubal serous borderline tumors with torsion are rare and diagnostically challenging. Clinicians should consider paratubal origin in the differential diagnosis of adnexal masses. Recognition of limitations in low-resource settings and prioritization of fertility preservation are essential for optimal patient care.