Raising Awareness of Intraoperative Diagnostic Challenges to Prevent Misdiagnosis and Overtreatment: Laparoscopic Management of Rare Cotyledonoid Dissecting Leiomyoma Mimicking Ovarian Tumour

Cotyledonoid dissecting leiomyoma (CDL), also known as Sternberg tumour, is a rare variant of leiomyoma that can be easily mistaken for a malignant neoplasm on clinical and radiological examination, posing a diagnostic challenge for clinicians. <b>Background:</b> Although the tumour can extend to neighbouring organs, it typically does not invade them and is considered benign. Therefore, it is essential to recognise and differentiate this leiomyoma variant from other malignancies to avoid misdiagnosis and overtreatment. <b>Methods:</b> This report depicts a unique case of CDL misdiagnosed as an ovarian tumour in a woman in her late 50s with post-menopausal bleeding and pelvic pressure. We initially planned and proceeded with a diagnostic laparoscopy and laparoscopic oophorectomy of the right ovarian mass, during which an intraoperative surprise of a retroperitoneal mass was explored and subsequently biopsied. <b>Results:</b> The final histopathology confirmed the presence of the rare fibroid variant CDL. The accompanying surgical video is among the first to feature a laparoscopic surgery of CDL and details the intraoperative findings and laparoscopic resection techniques utilised in this case. <b>Conclusions:</b> Given its rarity and non-specific clinical and radiological findings, diagnosing CDL pre-operatively can be challenging. This case prompts recognition and awareness of CDL and highlights the importance of careful consideration of uncommon differential diagnoses and thorough intraoperative exploration, with the goal of preventing the misdiagnosis and, consequently, overtreatment of unknown masses.