Postoperative diagnosis of uterine florid cystic endosalpingiosis: a case report emphasizing diagnostic challenges and multimodal imaging correlation.

Background: Endosalpingiosis, a rare benign condition characterized by ectopic fallopian tube-like epithelium, often coexists with endometriosis. This case report presents a unique instance of florid cystic endosalpingiosis confined to the uterine myometrium-marking the first documented case without associated pelvic pathology. Using multimodal imaging and histopathological analysis, we highlight key diagnostic approaches to distinguish this condition from malignant mimics. Case presentation: A 47-year-old woman with a 2-year history of chronic pelvic pain and recent irregular bleeding underwent surgical exploration after imaging revealed isolated, non-communicating cystic lesions within the myometrium. Histopathological examination identified cyst walls lined with ciliated pseudostratified epithelium, confirmed as benign through immunohistochemistry. A 6-year follow-up showed no evidence of recurrence. Conclusion: Florid cystic endosalpingiosis should be considered in the differential diagnosis of cystic uterine lesions. Establishing standardized imaging criteria and adopting fertility-preserving management strategies can help avoid unnecessary radical interventions, optimizing outcomes for premenopausal women.