External ureteral involvement as a result of ovarian cancer initially suspected as endometriosis leading to the diagnosis of squamous cell carcinoma.

Ovarian squamous cell carcinoma [SCC] is a rare and aggressive malignancy that can mimic benign gynecological disorders, often leading to diagnostic delays and suboptimal management. Ureteral obstruction and subsequent hydroureteronephrosis due to extrinsic compression are atypical initial presentations of ovarian SCC. A 39-year-old female presented with nausea, vomiting, anuria, and bilateral hydroureteronephrosis, initially suspected to be endometriosis. Given the severity of acute kidney injury, emergent hemodialysis was initiated. Imaging demonstrated bilateral distal ureteral obstruction, necessitating percutaneous nephrostomy and subsequent referral for definitive management. Intraoperative findings revealed extensive fibrosis and adhesions, warranting left salpingo-oophorectomy and bilateral ureteroneocystostomy with double-J stent placement. Histopathological analysis confirmed ovarian SCC with direct ureteral invasion and hepatic metastases. Despite surgical intervention and palliative systemic therapy, the disease exhibited rapid progression, ultimately culminating in patient mortality. This case underscores the diagnostic complexities of ovarian SCC presenting with obstructive uropathy and highlights the necessity of maintaining a high index of suspicion for malignancy in patients with bilateral hydroureteronephrosis of unclear etiology. A timely, multidisciplinary approach integrating urological and oncological expertise is paramount in optimizing clinical outcomes.