Idiopathic ovarian vein thrombosis in a nonpregnant premenopausal woman in her 40s: A case report.

Ovarian vein thrombosis (OVT) is a rare and often underdiagnosed condition, most frequently associated with pregnancy, infection, malignancy, or recent surgery. Idiopathic OVT (i.e. that occurring in the absence of identifiable risk factors) is exceedingly uncommon and can easily be overlooked due to its non-specific presentation. This article reports the case of a 40-year-old multiparous woman who presented with a 6-day history of severe left-sided lower abdominal pain associated with fever and nausea. Clinical examination demonstrated left iliac fossa tenderness without palpable adnexal masses. Contrast-enhanced computed tomography (CT) showed a bulky left ovary and left ovarian vein, initially reported as suggestive of left adnexal torsion. Given the presumed diagnosis, diagnostic laparoscopy was undertaken and revealed a thrombosed left ovarian ligament without torsion, leading to left partial salpingectomy. Postoperatively, the final CT report concluded that the appearances were highly suggestive of left ovarian vein thrombosis. The patient was commenced on anticoagulation following haematology consultation. This case demonstrates that OVT may arise in the absence of known risk factors and highlights the diagnostic challenges when it mimics more common acute pelvic pathologies. Careful radiological review, multidisciplinary involvement, and a high index of suspicion are essential to avoid unnecessary surgical intervention and ensure timely anticoagulation in stable patients.