Computed tomography and magnetic resonance imaging findings in a rare case of spontaneously ruptured ovarian endometrioma

Introduction: An uncommon occurrence associated with ovarian endometrioma is the unexpected rupture of the endometriotic cyst. This condition represents a gynecologic emergency that needs rapid identification and differential diagnosis with other more common gynecological and non-gynecological diseases. Imaging plays an important role in this context, and in particular, magnetic resonance imaging (MRI) allows for narrowing down the range of differential diagnoses before proceeding to surgery. Case description: We present the case of a 21-year-old woman, nullipara, admitted to the emergency department for diffuse abdominal pain. Blood tests showed an increased white blood cell count, increased levels of C-reactive protein, normal levels of beta-human chorionic gonadotropin, and increased levels of some tumor markers. The contrast-enhanced computed tomography (CT) showed peritoneal effusion and a suspected left ovarian mass without macroscopic signs of active bleeding. The subsequent contrast-enhanced MRI documented a left ovarian hemorrhagic cystic mass with hemoperitoneum, allowing the presence of tubo-ovarian abscess, mature cystic teratoma, and malignancy to be ruled out with high probability. The patient underwent diagnostic and operative laparoscopy with peritoneal washing, adhesiolysis, and removal of the left ovarian mass. The final histologic diagnosis was an endometriotic cyst. Conclusion: Our case illustrates that CT scanning facilitates the straightforward identification of pelvic mass lesions and a preliminary diagnosis of a gynecologic emergency. Nevertheless, MRI should be employed to refine the differential diagnosis and for preoperative planning. The conclusive identification of endometriosis is achieved through direct laparoscopic examination and histological confirmation.