Canal of Nuck Cyst with Endometriosis Presenting as a Left Inguinal Mass: A Rare Clinical Variant

A cyst of the canal of Nuck is a rare clinical entity in females, resulting from the failure of obliteration of the processus vaginalis. Although it is typically diagnosed in the pediatric population, it is extremely rare in adult women and often misdiagnosed as an inguinal hernia, leading to delays in appropriate treatment. Clinically, it usually presents as a painless, fluctuating mass in the inguinal region. Ultrasonography is the primary imaging modality for diagnosis, while magnetic resonance imaging (MRI) can further delineate the origin and anatomical relationships of the lesion. Surgical excision remains the standard treatment approach. Herein, we present the case of a 34-year-old woman who presented with a painless swelling in the left inguinal region. A preoperative diagnosis was established based on imaging findings, and the lesion was surgically excised. Histopathological examination revealed a focus of endometriosis within the cyst wall. This case highlights the importance of considering rare coexisting pathologies such as endometriosis in the differential diagnosis of canal of Nuck cysts in adult women and aims to raise clinical awareness of this uncommon presentation.