Computed tomography diagnosis of omental infarction presenting as an acute abdomen

Are all primary omental infarcts truly idiopathic? Five case reports

BACKGROUND

Idiopathic omental infarction (IOI) is challenging to diagnose due to its low incidence and vague symptoms. Its differential diagnosis also poses difficulties because it can mimic many intra-abdominal organ pathologies. Although hypercoagulability and thrombosis are among the causes of omental infarction, venous thromboembolism scanning is rarely performed as an etiological investigation.

CASE SUMMARY

The medical records of the 5 cases, who had the diagnosis of IOI by computed tomography, were examined. The majority of the patients were male (n = 4, 80%) and the mean age was 31 years (range: 21-38). The patients had no previous abdominal surgery or a history of any chronic disease. The main complaint of all patients was persistent abdominal pain. Omental infarction was detected in all patients with contrast-enhanced computed tomography. Conservative treatment was initially preferred in all patients, but it failed in 1 patient (20%). After discharge, all patients were referred to the hematology department for thrombophilia screening. Only 1 patient applied for thrombophilia screening and was homozygous for methylenetetrahydrofolate reductase (A1298C mutation) and heterozygous for a factor V Leiden mutation.

CONCLUSION

IOI should be considered in the differential diagnosis in patients presenting with progressive and/or persistent right side abdominal pain. Investigating risk factors such as hypercoagulability in patients with IOI is also important in preventing future conditions related to venous thromboembolism.

Imaging Features of Uncommon Entities That Manifest with Torsion

Torsion is the twisting of an object along the axis, and various structures (organs and tumors) in the body can twist. Torsion causes initial lymphatic and venous outflow obstruction, leading to congestive edema, enlargement, venous hemorrhagic infarction, and surrounding edema. It can also cause subsequent arterial obstruction depending on the degree of torsion, leading to ischemia, infarction, necrosis, gangrene, and surrounding inflammation. Therefore, in several cases of torsion, immediate surgical intervention is required to improve blood flow and prevent serious complications. Clinical manifestations of torsion are often nonspecific and can affect individuals of varying ages and sex. Imaging plays an important role in the early diagnosis and management of torsion. Multiple imaging modalities, including US, radiography, CT, and MRI, are used to evaluate torsion, and each modality has its specific characteristics. The imaging findings reflect the pathophysiologic mechanism: a twisted pedicle (whirlpool sign), enlargement of the torsed structures, reduced blood flow, internal heterogeneity, and surrounding reactive changes. The whirlpool sign is a definitive characteristic of torsion. In some cases, despite poor internal enhancement, capsular enhancement is observed on contrast-enhanced CT and MR images and is considered to be associated with preserved capsular arterial flow or capsular neovascularization due to inflammation. Radiologists should be familiar with the pathophysiologic mechanisms, clinical characteristics, and imaging characteristics of torsion in various structures in the body. Since other articles about common organ torsions already exist, the authors of this article focus on the uncommon entities that manifest with torsion. ©RSNA, 2024.

Omental Infarction Mimicking Acute Appendicitis: A Case Report

Acute abdominal pain is a common presentation in emergency departments, often attributed to a myriad of potential causes. Among these, acute appendicitis remains a frequently diagnosed culprit. However, this case report presents a 32-year-old male who arrived at the emergency department with severe right lower quadrant abdominal pain, characterized by localized tenderness and guarding. The initial clinical diagnosis pointed to acute appendicitis. Before surgical intervention, a computed tomography scan was conducted and revealed a focal area of fat stranding, consistent with omental infarction, while the appendix appeared normal. The patient's management involved pain control and supportive care, leading to a complete resolution of abdominal pain at a two-week follow-up. This case emphasizes the significance of including omental infarction in the spectrum of diagnoses for acute abdominal pain, underlining the potential to prevent unnecessary surgical interventions.

Primary omental torsion in children: single-center experience of 17 cases

OBJECTIVE

Primary omental torsion (POT) is a rare condition in children often misdiagnosed because of a lack of clinical manifestations. Here we present insights gained from the treatment of pediatric POT cases at a single center over 8 years and summarize some influencing factors found in diagnosis and treatment, in order to reduce the misdiagnosis of POT in children in the future.

METHODS

Demographic and clinical data of 17 children with POT treated in Shanghai Children's Hospital, Shanghai Jiaotong University from June 2012 to December 2020 were reviewed.

RESULTS

The mean age of the 17 pediatric patients was 7.65 ± 2.12 years (range: 4-12 years), sixteen were male. The average time from the pain onset to operation was 73.82 ± 47.21 h (range: 21-144 h). In 5 cases, the ultrasound scan revealed a low-intensity inflammatory mass in the abdominal cavity. Only 1 of the 17 patients had normal body mass index, while others were overweight or obese. The mean computed tomography (CT) value of the mass in the lower right abdomen was - 58.74 ± 10.32 HU (range: - 70 to - 46 HU), which is close to that of its own abdominal wall fat [- 46.29 ± 9.45 HU (range: - 62 to - 32 HU)]. The location of the mass was located in front of the right colon in ten cases, except for two cases near the ligamentum teres. Five patients had whirl sign on CT images and 8 patients had pelvic fluid. Five cases were diagnosed as acute appendicitis and 12 were diagnosed as POT, the preoperative diagnosis was correct in 70.59% of cases. All 17 patients were treated with laparoscopic omentectomy. The average duration of hospitalization was 5.53 ± 1.12 days (range: 4-8 days). All cases were followed up. 1 case relapsed 8 months post operation, while the remaining cases had no complications.

CONCLUSION

POT is rare in children with acute abdominal pain, which is more common in obese boys. The fatty mass in front of colon and between rectus abdominis sheath in CT image is specific, which is helpful for diagnosis of POT. Laparoscopy is an effective method for the treatment of POT in children.

Omental infarction present with right upper quadrant pain, case report

Omental infarction is a rare cause of pain and must be considered in the differential diagnosis of acute abdomen. It arises in any quadrant that contains omentum when a compromised blood supply takes place. We report a morbid obese 45-year-old male with Diabetes mellitus, dyslipidemia and coronavirus-disease-related pneumonia 2 months prior to his emergency presentation with acute epigastric and right upper quadrant pain. The patient was investigated by computed tomography (CT), and the provisional diagnosis was biliary colic from gallbladder stone. The patient’s pain was severe and not compatible with biliary colic. Diagnostic laparoscopy approached and an incidental finding of omental necrotic area. Excision of the infarcted omentum in addition to cholecystectomy was done. The patient’s postoperative course was uneventful, and he was discharged home after 2 days. In our case, the CT image did not discover mental changes that may help us to make a preoperative diagnosis.

Laparoscopic Surgery for Diagnosis and Treatment of Acute Right Upper-Quadrant Abdominal Pain Due to Omental Infarction: A Report of a Rare Case in a Single Vietnamese Hospital

Case series

Patients: Female, 56-year-old • Female, 58-year-old

Final Diagnosis: Omental infarction • omental torsion

Symptoms: Abdominal and/or epigastric pain • nausea • right upper quadrant pain • vomiting

Medication: —

Clinical Procedure: Laparoscopic ometectomy • omentectomy

Specialty: Surgery

Non-operative management of primary omental torsion, a case report and literature review

Primary omental torsion is a rare cause of acute abdomen especially in obese patients with inconsistent history, examination, and laboratory findings. The liberal use of computed tomography in casualties has increased its preoperative diagnosis. Despite the controversy, the non-operative approach should be attempted as a first line of management while the laparoscopic resection should be only considered after failure of non-operative management.

Not Just Fat: Imaging in Abdominal Fat Pathology

Fat in abdomen has diverse distribution and function. Insult to fat due to several causes can result in infarction or necrosis and present as acute abdomen clinically. Intra-abdominal focal fat infarction is one such condition that comprises of epiploic appendagitis, perigastric appendagitis, omental infarction, and torsion of fatty appendage of falciform ligament that have characteristic imaging features. Secondary causes of fat necrosis include pancreatitis or trauma related. Metabolic or responsive fat changes, like hypertrophy and dystrophy, can be diagnosed on imaging especially on computed tomography. Mesentric fat stranding including the mesentric panniculitis spectrum poses diagnostic dilemma and the causes and imaging role are covered in this review. Some infections and neoplasms that preferably affect abdominal fat compartments may mimic benign conditions, although some have specific patterns of involvement.