An Exceptionally Rare Ovarian Lymphangioma Mimicking a Dermoid Cyst Recurrence: A Case Report.

Ovarian lymphangioma is an exceptionally rare benign tumour derived from lymphatic vessels, with only a few cases reported worldwide. The imaging features are nonspecific and often resemble those of common adnexal lesions, such as dermoid cysts, cystadenomas, or endometriomas. Therefore, a definitive preoperative diagnosis is difficult, making histopathological confirmation essential. Surgical excision, either by cystectomy or oophorectomy, is the treatment of choice, with a favourable prognosis when excised completely. However, because of the rarity of this condition, there are no established evidence-based recommendations for postoperative surveillance, and follow-up is usually tailored to the individual after multidisciplinary review. We report a unique case of an ovarian lymphangioma coexisting with a haemorrhagic corpus luteal cyst, initially mistaken for a recurrent dermoid cyst after laparoscopic cystectomy. The patient, a woman in her 30s, presented several months after surgery with pelvic pain and prolonged menstrual bleeding. Ultrasound evaluation suggested a recurrent dermoid cyst. She subsequently underwent laparoscopic right salpingo-oophorectomy, and histopathological analysis confirmed the diagnosis. This case highlights the importance of maintaining a broad differential diagnosis when symptoms or lesions recur following complete dermoid excision. Histopathological evaluation is crucial to ensure diagnosis, while multidisciplinary discussion facilitates appropriate follow-up planning. Greater awareness of this rare entity may help clinicians avoid misdiagnosis and implement individualised postoperative surveillance.