A 30 years old female patient under anticoagulation therapy for a valvular cardiopathy presented at the emergency department for biliary vomit, diarrhoea, and hypotension. The blood exams showed low haemoglobin levels. The clinical examination was otherwise unremarkable.
The patient underwent an abdominal CT scan showing the presence of free fluid in the whole abdomen without free air (Figure 1). Within the anterior central pelvis, there was a large lesion with hypodense and enhancing areas (Figure 2). This finding was adjacent to the right ovary, where two cystic lesions with enhancing borders were visible (Figure 3). There was no evidence of active arterial bleeding during the arterial phase. The central pelvic lesion finding was interpreted as a large hematoma, but the suspect of a bleeding adnexal mass was raised. Therefore, the patient underwent an MR examination that showed a cystic lesion in the right ovary, slightly hyperintense in the T1w image also after fat suppression (Figure 4), with a restricted DWI (Figures 5 and 6). The median lesion within the pelvis showed inhomogenous intensity on T2w images (Figure 7), no restricted diffusion and no enhancement after gadolinium injection (Figure 8).
Hemoperitoneum is a rare cause of acute abdomen. In women of reproductive age, ruptured corpus luteal cysts are the commonest cause of spontaneous hemoperitoneum . Corpus luteum is a functional cyst developing in the luteal phase of the ovarian cycle that regresses spontaneously in corpus albicans when pregnancy does not occur. Being a thin-walled vascular structure corpus luteum is prone to haemorrhage, but bleeding is usually contained within the cyst. If the corpus luteum cyst-wall breaks, haemorrhage may spread into the peritoneal cavity, causing hemoperitoneum.
Clinical presentation of corpus luteum rupture is variable, ranging from completely asymptomatic to severe abdominal pain due to peritoneal irritation. Personal history may help to make the correct diagnosis since the patient is generally in the luteal phase of the ovarian cycle, shows pain and laboratory tests indicate the presence of anaemia. However, these signs and symptoms are similar to gastrointestinal tract diseases, ruptured ectopic pregnancy, and complicated appendicitis. Furthermore, some ovarian tumours may rarely present in young women with rupture and hemoperitoneum (e.g.dysgerminoma, clear cell carcinoma , granulosa cell tumour , mucinous cystadenocarcinoma ).
The presence of free fluid not hypodense on CT scan should suggest bleeding and an arterial phase is needed to exclude active bleeding [5-7]. Secondarily, the presence of a mass-like lesion should suggest evaluating causes associated with malignancies in young age, such as familiar history for cancers . To this end, MRI is of great help because the hyperintensity on T1w and T1 FS images suggests the presence of blood, and the images after contrast medium show the absence of enhancing tissue . DWI in presence of bleeding may be misleading because blood may show restricted diffusion .
According to the clinical presentation, patients with hemoperitoneum may undergo observation or laparoscopy to evacuate the blood and to fix its origin, being the extension of the surgery related to the cause of bleeding. In this case, the patient underwent a laparoscopic peritoneal washing and coagulation of the right ovary, with prompt resolution of the symptoms and she was discharged the day after surgery.
Take Home Message
When facing hemoperitoneum in a young patient, the first hypothesis should be the rupture of a haemorrhagic corpus luteum. However, it is mandatory to consider also other causes and to suggest any differential diagnosis according to the imaging findings.
 Fiaschetti V, Ricci A, Scarano AL, Liberto V, Citraro D, Arduini S, Sorrenti G, Simonetti G (2014) Hemoperitoneum from corpus luteal cyst rupture: a practical approach in emergency room. Case Rep Emerg Med. 2014:252657. doi: 10.1155/2014/252657. PMID: 24987535
 López-Rublo MA, Gómez-García MT, Rubio-Moreno MA, González-De Merlo G (2015). Spontaneous hemoperitoneum and clear cell tumor of ovary. Ginecol Obstet Mex. 83(9):551-5. PMID: 26591044.
 Bastu E, Akhan SE, Karamustafaoglu B, Gungor-Ugurlucan F, Sozen H, Iyibozkurt AC. (2013) Hemoperitoneum and acute abdomen caused by the rupture of ovarian granulosa cell tumor: a case report. Eur J Gynaecol Oncol. 34(3):263-4. PMID: 23967560.
 Casal Rodriguez AX, Sanchez Trigo S, Ferreira Gonzalez L, Brage Gomez S. (2011) Hemoperitoneum due to spontaneous rupture of ovarian adenocarcinoma. Emerg Radiol. 18(3):267-9. doi: 10.1007/s10140-010-0929-0. PMID: 21221696.
 Ichikawa S, Onishi H. (2022) Computed tomography and magnetic resonance imaging findings of gynaecologic emergencies: A pictorial essay. J Med Imaging Radiat Oncol. 66(5):654-661. doi: 10.1111/1754-9485.13450. PMID: 35751641.
 Choi HJ, Kim SH, Kim SH, Kim HC, Park CM, Lee HJ, Moon MH, Jeong JY. (2003) Ruptured corpus luteal cyst: CT findings. Korean J Radiol. 4(1):42-5. doi: 10.3348/kjr.2003.4.1.42. PMID: 12679633
 Potter AW, Chandrasekhar CA (2008). US and CT evaluation of acute pelvic pain of gynecologic origin in nonpregnant premenopausal patients. Radiographics. 28(6):1645-59. doi: 10.1148/rg.286085504. PMID: 18936027.
 Rizzo S, Cozzi A, Dolciami M, Del Grande F, Scarano AL, Papadia A, Gui B, Gandolfo N, Catalano C, Manganaro L. (2022) O-RADS MRI: A Systematic Review and Meta-Analysis of Diagnostic Performance and Category-wise Malignancy Rates. Radiology. 22:220795. doi: 10.1148/radiol.220795. Epub ahead of print. PMID: 36413127.
 Tonolini M, Foti PV, Costanzo V, Mammino L, Palmucci S, Cianci A, Ettorre GC, Basile A. (2019) Cross-sectional imaging of acute gynaecologic disorders: CT and MRI findings with differential diagnosis-part I: corpus luteum and haemorrhagic ovarian cysts, genital causes of haemoperitoneum and adnexal torsion. Insights Imaging. 10(1):119. doi: 10.1186/s13244-019-0808-5. PMID: 31853900
 Bhatt A, Masih A, Grothous HF, Farooq MU, Naravetla B, Kassab MY. (2009) Diffusion-weighted imaging: not all that glitters is gold. South Med J.102(9):923-8. doi: 10.1097/SMJ.0b013e3181a9142a. PMID: 19668055.
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