the typical clinical presentation of poi is pain in the right side of the abdomen , and this may lead to a misdiagnosis of acute appendicitis or cholecystitis . here , we present a case of poi , with pain in the left lower quadrant . a 50-year - old woman admitted to the emergency room with a history of worsening abdominal pain for 5 days . the pain began in the upper abdomen and later localized to the left lower quadrant , and the pain intensity exacerbated with activities . the pain was sharp and constant in nature without nausea or vomiting . on physical examination , the patient was febrile with a temperature of 38.1c and had severe left lower quadrant tenderness and abdominal rigidity . the previous history included an open ectopic pregnancy surgery in 1996 , and no atrial fibrillation , no venous thrombosis , no contraceptive , or aspirin usage . the laboratory test showed white blood cell 9.71  10/l , d - dimer 1.58 mg / l , and no other abnormalities . an abdominal computed tomography ( ct ) was performed and showed a left ovarian cyst measuring 6.0 cm  4.5 cm with no other remarkable findings [ figure 1a ] . after about 1 day , the patient complained of worsening abdominal pain and absence of passage of feces and gas . ( a ) axial image showed a left ovarian cyst measuring 6.0 cm  4.5 cm . median sagittal section showed an increased fat - density mass consequently , we performed laparoscopic exploration . during the procedure , we found a segment of congested necrotic omentum adhering to the abdominal wall with a segment of small intestine [ figure 2a ] , bloody ascites ( 200 ml ) accumulated in the abdominal cavity [ figure 2b ] , and an ovarian cyst measuring 6.0 cm  4.5 cm in pelvic cavity [ figure 2c ] . we resected the nonviable omental segment , and the gynecologist removed the ovarian cyst using laparoscopic procedures . ( b ) a dark purple mass on the left side in the lower part of the omentum and bloody ascites in the left abdomen . ( c ) a huge ovarian cyst by reanalyzing the preoperative ct , a segmental fat mass with an increased density was noted in the left lower quadrant which was consistent with the intraoperative findings [ figure 1b ] . final pathological examination revealed hemorrhagic infiltrations , thrombosis of the tissue , acute inflammatory cellular infiltrate , and fibrinoid necrosis , and poi was diagnosed [ figure 3 ] . histological examination of the resected nonviable omentum revealed hemorrhagic infiltrations , thrombosis of the tissue , acute inflammatory cellular infiltrate , and fibrinoid necrosis up till now , only a few hundred cases have been published in the english literature . susceptible factors include ( 1 ) anatomic malformations such as a bifid or accessory omentum causing the spontaneous torsion , ( 2 ) sudden movement , violent exercise , and hyperperistalsis , and ( 3 ) obesity . most authors support the hypothesis that it is associated with an anomalous and fragile blood supply of the right lower portion of the omentum , which is consequently susceptible to infarction . thus , 90% of all the cases have initial pain in the right side of the abdomen . our patient had pain in the left lower quadrant , so we did not include poi in the differential diagnosis spectrum . poi has no early specific signs and is often characterized by progressive , persistent abdominal pain . clinical features include unspecific gastrointestinal symptoms , slightly febrile , and mild leukocytosis . in the present case , d - dimer can be used as an objective parameter in the differential diagnosis of poi as it is used in other thromboembolic diseases . the most diagnostic finding is an ill - defined heterogeneous fat density with surrounding inflammatory changes . by retrospective reanalysis of the preoperative ct in this study , ultrasound is specific but not sensitive for diagnosing poi ; suspected imaging features include hyperechoic , incompressible , ovoid mass , and detectable in < 50% of cases , even when reviewed retrospectively . two patients underwent surgery , one because of the absence of spontaneous regression and the other because of extremely severe clinical symptoms . in the other four patients , conservative management was given and successful . if a confirmed diagnosis of poi can be made with the typical clinical signs and imaging studies , conservative treatment is the first - line therapy during the first 2448 h while resuscitation and antibiotics are initiated . however , if the diagnosis is in doubt or if conservative treatment fails , laparoscopy should be performed without delay . as in the present case , the pain was not relieved after conservative treatment for 24 h. intestinal obstruction occurred as a segment of small intestine adhered to the abdominal wall . poi should be considered in the differential diagnosis of any patient presenting with acute abdominal pain . laparoscopic exploration should be performed if new symptoms occur or do not relieve within 2448 h. there are no conflicts of interest .
primary omental infarction ( poi ) is a rare cause of acute abdomen . 
 most patients have aggravating abdominal pain without gastrointestinal symptoms . here , we report a case of omental infarction in a 50-year - old woman , who had left abdominal pain and intestinal obstruction . preoperative computed tomography ( ct ) of the abdomen showed a left ovarian cyst measuring 6.0 cm  4.5 cm but otherwise seemed normal initially . 
 the white blood cell count was 9.71  109/l , and d - dimer was 1.58 mg / l . 
 laparoscopic exploration was performed 1 day after admission because of peritonitis and intestinal obstruction . during the exploration 
 , a segment of congested necrotic omentum was found adhering to the abdominal wall with a segment of small intestine . 
 bloody ascites was also observed in the abdominal cavity . 
 we resected the nonviable segmental omentum , and the ovarian cyst was removed by the gynecologist using laparoscopic procedures . 
 final pathological findings confirmed poi . while reanalyzing the preoperative ct , a segmental fat mass with an increased density 
 was noted in the left lower quadrant , which was consistent with the intraoperative view 6 days after surgery . 
 the patient recovered uneventfully and was discharged .