Computed tomography of a canine omental torsion secondary to a chronic abdominal gossypiboma and concurrent incidental broad ligament torsion

A 5-year-old female spayed Dogue de Bordeaux was referred for concerns of an abdominal mass and peritoneal effusion. Abdominal radiographs identified a mid-ventral abdominal soft tissue opaque mass containing a radiopaque marker consistent with a gossypiboma. Contrast-enhanced abdominal CT identified two whirl signs associated with the abdominal gossypiboma. Exploratory laparotomy confirmed an omental torsion with encapsulated gossypiboma and concurrent incidental torsion of the remnant of the right broad ligament. Based on a literature review, omental torsions are an unreported complication of gossypibomas in canids.

Ruptured primary omental ectopic pregnancy during the first trimester

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Omental infarction in an overweight child: conservative treatment is a safe approach

A previously healthy but overweight (body mass index (BMI) of 24.4) adolescent boy presented with fever and significant right-sided abdominal pain. An abdominal ultrasound scan revealed an omental infarction (OI), which was treated conservatively. OI has been described in overweight teenage children with abdominal trauma but can be missed if not considered. A missed diagnosis could result in an unnecessary laparotomy or laparoscopic surgery. Although CT is the gold standard for diagnosis, ultrasonography is an effective approach to identifying OI in children. The benefits of early diagnosis of OI by abdominal ultrasound include a shorter hospital stay and a reduction in unnecessary investigations and surgery.

Inguinal hernia leading to omental torsion: Role of CT in differentiating from other clinical mimics - a case report and literature review

Omental torsion is a very rare cause of acute abdomen. Clinically, it mimics other common pathologies such as acute appendicitis, acute diverticulitis and acute cholecystitis. It is therefore no surprise, that it was rarely diagnosed pre operatively before the advent and easy availability of modern imaging techniques. CT scan, in particular, can diagnose omental torsion with confidence pre operatively. This can make conservative treatment possible in cases of primary omental torsion and guide regarding the appropriate treatment in cases of secondary torsion. We present a case of a young male patient who presented to Emergency department with symptoms of acute abdomen. Clinical and laboratory findings were non-specific for any specific cause of acute abdomen. CT scan, however, showed omental fat stranding with whirlpool sign representing omental torsion which was seen to be secondary to left inguinal hernia. Patient was operated in emergency and necrotic omentum was resected and hernia repaired. Post-operative recovery was uneventful.

Peri-gastric appendagitis with lesser omentum hemorrhagic infarction: US, CT, and MRI findings of a rare entity

Peri-gastric appendagitis followed associated with gastro-hepatic ligament/lesser omentum hemorrhagic infarction has not been well investigated yet. With an accurate radiological diagnosis of peri-gastric appendagitis, even in case of hemorrhagic infarction, the patient can receive supportive measures for the self-limited pain and can forgo surgery, endoscopy, and further invasive testing.

Computed tomography of suppurative and neoplastic diseases involving the canine omenta and omental bursa

The greater and lesser omenta are fused peritoneal folds that largely delimit the omental bursa (lesser peritoneal cavity). The omental bursa is a potential space within the abdominal cavity that communicates with the greater peritoneal cavity via the omental (epiploic) foramen: it is subdivided into the omental vestibule, caudal omental recess, and splenic recess. Aims of this retrospective case series study were to describe the frequencies of CT findings of dogs with confirmed inflammatory or neoplastic disease of the omenta, omental bursa, or both. The sample included seven adult, medium-to-large breed dogs. All had fluid in the greater peritoneal cavity and 5/7 (71%) dogs also had fluid in the omental bursa. Primary suppurative inflammatory disease was present in three dogs, each dog had a large abscess with central gas in either the omental vestibule (two dogs) or caudal omental recess (one dog). Both abscesses in the omental vestibule arose from the papillary process of the caudate liver lobe and were surgically removed without complication. Neoplasia was present in four dogs and either arose from omentum (hemangiosarcoma, carcinoma) or infiltrated the omentum from an adjacent organ (splenic leiomyosarcoma, gastric adenocarcinoma). Neoplasms created mass-like tumors, infiltrative tumors, or both and had variable distribution (focal, multifocal, or locally extensive). All dogs with neoplasia were euthanized. CT signs of inflammatory and neoplastic disease overlapped, but the presence of gas might prioritize abscessation. CT signs helped decide feasibility of surgery based on extent of local invasion, especially involvement of structures passing through the porta hepatis.

Omental infarction mimicking acute appendicitis with negative radiological findings

A male in his 30s presented to the emergency department with a 1-day history of supra-umbilical pain migrating to the right iliac fossa. On examination, his abdomen was soft but tender with localised guarding in the right iliac fossa and a positive Rovsing's sign. The patient was admitted under a presumptive diagnosis of acute appendicitis. A CT scan and ultrasound scan of the abdomen and pelvis showed no acute intra-abdominal pathology. He stayed in hospital for 2 days for observation without improvement of symptoms. A diagnostic laparoscopy was therefore performed that revealed an infarcted omentum adherent to the abdominal wall and ascending colon causing congestion of the appendix. The infarcted omentum was resected, and the appendix was removed. The CT images were reviewed by multiple consultant radiologists, but no positive findings were appreciated. This case report demonstrates the potential difficulty in diagnosing omental infarction clinically and radiologically.

Ultrasonographic misdiagnosis of multicystic mesothelioma of the omentum: A case report

RATIONALE

Multicystic Mesothelioma (MM) is very rare and preoperative diagnosis is difficult.

PATIENT CONCERNS

We report a case of a 34-year-old man with solid abdominal cystic echo mass. Physical examination showed that the patient had a flat and soft abdomen without tenderness or rebound pain, no fluid wave tremor, and no obvious abdominal mass was touched. The patient complained of repeated abdominal distention with nausea for 5 days. Sonographic examination suspected pseudomyxoma peritoneum.

DIAGNOSIS

Conventional ultrasound examination showed a cystic solid echo mass in the right abdominal cavity of the patient, with uneven internal echo and honeycomb change, and clear boundary with surrounding organs. Color Doppler suggested that the blood flow in the mass was not obvious. Contrast-enhanced computed tomography of the abdomen revealed hypodensity foci in hepatic and renal crypts and right paracolic sulcus.

INTERVENTIONS

Laparoscopic resection of the mass was performed, and the postoperative pathological findings were polycystic mesothelioma (greater omentum).

OUTCOMES

After mass resection, all laboratory tests and abdominal ultrasound were normal, and abdominal distension and nausea disappeared.

LESSONS

Improved ultrasound diagnosis of MM is useful for clinical decision-making.

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.

Primary liposarcoma of the omentum: A case report

RATIONALE

Omental liposarcoma is extremely rare, and only a few reports have been published in the literature. Due to the rarity of the disease, establishing a clear diagnosis and formulating a treatment plan may be challenging for clinicians.

PATIENT CONCERNS

The patient was a 51-year-old woman who presented with a protruding mass and pain in the lower abdomen.

DIAGNOSIS

Magnetic resonance imaging revealed a tumor measuring 15 cm in diameter in the pelvis. Ovarian cancer was suspected based on pre-operative imaging findings.

INTERVENTIONS

An exploratory laparotomy was performed. Intra-operative analysis of the frozen section suggested a benign tumor.

OUTCOMES

Postoperative histopathological analysis confirmed the diagnosis of omental liposarcoma. The patient recovered well after surgery.

LESSON

This case report helps clinical oncologists to develop a comprehensive understanding of this disease and treat it accordingly.

Omental desmoplastic small round cell tumor with metastasis

Desmoplastic small round cell tumor (DSRCT) is a very rare diagnosis with about 200 cases reported in literature. DSRCT is a recently described histopathological entity by Gerald and Rosai in 1989. Abdominopelvic cavity especially peritoneum is the most common site. We report a case of a huge omental DSRCT with lymph node metastasis which was initially misdiagnosed as gastrointestinal stromal tumor on radiology. A 26-year-old male presented with complaints of upper abdominal swelling associated with constant dull pain. On examination there was a large 15 × 12 cm intraabdominal mass in the epigastric and umbilical region. Imaging studies were suggestive of neoplastic mesenchymal etiology. Image-guided fine-needle aspiration cytology (FNAC) was suggestive of mesenchymal neoplastic etiology. On laparotomy, there was a huge 20 × 15 cm mass arising from omentum with multiple omental and mesenteric seedlings and mesenteric, peripancreatic and perigastric lymphadenopathy. The patient underwent debulking surgery with uneventful post-operative recovery. Histopathological examination with immunohistochemistry revealed a diagnosis of DSRCT of omentum and small bowel mesentery with lymph node metastasis. Patient then received adjuvant chemotherapy with multiple chemotherapeutic drugs as per P6 protocol and has stable disease at 1 year follow up.

Omental Infarction: An Underrecognized Cause of Right-Sided Acute Abdominal Pain in Children

OBJECTIVE

To evaluate the prevalence of omental infarction (OI) in children with suspected appendicitis, the role of ultrasonography (US) in its diagnosis and management and the efficacy of conservative management.

METHODS

Consecutive children with suspected acute appendicitis were prospectively enrolled. Ultrasonography was performed at baseline, during follow-up, before the discharge, and at 15-day intervals until US findings of OI disappeared. All children with a diagnosis of OI were treated conservatively.

RESULTS

One hundred ninety-nine children (91 male; age range, 3-15 years) were evaluated. Eighty-four patients had acute appendicitis. Omental infarctions were found in 14 children (8 male; mean age, 9.8 ± 2.6 years), with an incidence of 7%. Ultrasonography depicted an echogenic mass consistent with OI in all children. Ultrasonography detected in 8 patients a normal-looking appendix, whereas in other 6 patients, it identified neither appendix nor indirect signs of acute appendicitis. A normal appendix has been detected by US during follow-up in 2 of these 6 patients. During follow-up, US finding of OI disappeared in all cases and no signs of acute appendicitis or other disease occurred. All 14 OIs were treated conservatively, with no reported complications.

CONCLUSIONS

Omental infarction is an underestimated cause of abdominal pain in children accounting for 7% of patients with suspected appendicitis. Ultrasonography is a useful method for the diagnoses and to guide clinical management of OI. Conservative therapy is a safe option for the management of OI.

Characterizing omental PET/CT findings for differentiating tuberculous peritonitis from peritoneal carcinomatosis

PURPOSE

To characterize and investigate PET/CT findings in the omentum in the differentiation of tuberculous peritonitis (TBP) and peritoneal carcinoma (PC).

METHODS

Thirty-nine patients with TBP and 113 patients with PC who underwent PET/CT were retrospectively enrolled. The omental uptake intensity, distribution characteristics, contracture, size and boundary of soft-tissue lesions, and CT patterns were reviewed.

RESULTS

Absent and focal FDG uptake in the lesser omentum was more common in the PC patients (P = 0.034 and P = 0.017, respectively), and diffuse FDG uptake in the lesser omentum was more common in the TBP patients (P < 0.001). An apron-like pattern in the greater omentum commonly occurred in the TBP patients (P = 0.004). Micronodules (< 5 mm) were more common in the TBP patients (P < 0.001), and masses (> 3 cm) were more common in the PC patients (P = 0.001). Smudged and nodular patterns occurred more frequently in the TBP patients than in the PC patients (P < 0.001 and P = 0.003, respectively), and the caked pattern occurred more frequently in the PC patients (P < 0.001). There was no significant difference in the FDG uptake intensity and the boundary of soft-tissue lesions between the TBP and PC patients (P = 0.191 and P = 0.061, respectively).

CONCLUSION

Diffuse FDG uptake, an apron-like pattern, micronodules, and a smudged and nodular pattern might be significant differential features of TBP. Absent and/or focal FDG uptake, mass, and a caked pattern might be significant differential features of PC.

Encapsulated Omental Necrosis as an Unexpected Postoperative Finding: A Case Report

Postsurgical fat necrosis is a frequent finding in abdominal cross-sectional imaging. Epiploic appendagitis and omental infarction are a result of torsion or vascular occlusion. Surgery or pancreatitis are conditions that can have a traumatic and ischemic effect on fatty tissue. The imaging appearances may raise concerns for recurrent malignancy, but percutaneous biopsy and diagnostic follow-up assist in the accurate diagnosis of omental infarction. Herein we describe a case of encapsulated omental necrosis temporally related to gastric surgery. Preoperative CT and MRI findings showed the characteristics of encapsulated, postcontrast nonviable tumefaction in the epigastrium without clear imaging features of malignancy. Due to the size of the lesion and the patient’s primary disease, tumor recurrence could not be completely ruled out, and the patient underwent surgery. Histopathological analysis confirmed the diagnosis of steatonecrosis of the omentum.

[Omental infarction with omental torsion, arare condition very seldom suspected clinically]

This is a case report of an adult female with omental infarction caused by internal herniation and omental torsion. The patient, who had no previous surgical record, presented with three days of pain in the right upper quadrant. Ultrasound evaluation showed no signs of cholecystitis, after which an abdominal computed tomography confirmed the diagnosis. The patient underwent laparoscopic omentectomy, with an uneventful recovery. This case highlights the importance of radiological and surgical awareness of this rare condition.

Lung cancer combined with diffuse peritoneal and mesenteric amyloidosis detected on 18F-FDG PET/CT: A case report

RATIONALE

Amyloidosis is a heterogeneous group of diseases characterized by extracellular deposition of amyloid fibrils. Lung carcinoma is rarely reported to be associated with AA amyloidosis. With regard to the manifestation of amyloidosis infiltrating organs, most of the cases focus on the heart, liver, kidneys, and peripheral nervous system. Amyloidosis with diffuse abdominal involvement in combination with pulmonary squamous cell carcinoma carcinoma is an exceptionally rare occurrence.

PATIENT CONCERNS

A 70-year-old man was admitted to hospital for a 2-month history of repeated cough, low grade fever, hemoptysis and left back shoulder pain, which was not relieved by nonsteroid anti-inflammatory drugs. Meanwhile, he complained of intermittent diffuse abdominal discomfort and chronic persistent constipation.

DIAGNOSES

The patient was diagnosed with poorly differentiated lung squamous cell carcinoma and diffuse peritoneal and mesenteric amyloidosis based on the pathological biopsy.

INTERVENTIONS

The patient received surgery and chemotherapy for lung tumor. He did not receive any treatment against amyloidosis.

OUTCOMES

The patient died of a severe respiratory infection.

LESSONS

This case indicates that lung carcinoma is suspected to play a causative role in the development of amyloidosis. In addition, amyloidosis should be considered in the differential diagnosis in cases in which diffuse greater omentum, peritoneal, and mesenteric calcifications on 18F-2-fluoro-2-deoxy-D-glucose(18F-FDG) photon emission computed tomography (PET/CT).

Rapidly Evolving Diffuse Omental Carcinomatosis of Prostate Cancer in 68Ga-PSMA PET/CT

ABSTRACT

An 81-year-old man received androgen deprivation therapy for a locally advanced prostate cancer and, 6 months later, a curative radiation therapy. Half a year later, the patient presented with a steeply increased PSA value (32 ng/mL) and a suppressed testosterone level (0.48 nmol/L). The consecutively performed 68Ga-PSMA PET/CT revealed, besides local tumor remains and several PSMA-positive lymph node and soft tissue metastases, an extensive, diffuse PSMA ligand accumulation in the omentum, which was immunohistochemically proven to be a carcinomatosis of prostate cancer. None of the extraprostatic lesions were present in the pretherapeutic PSMA PET 1 year ago.

Spontaneous regression of gastric gastrinoma after resection of metastases to the lesser omentum: A case report and review of literature

BACKGROUND

Gastric gastrinoma and spontaneous tumor regression are both very rarely encountered. We report the first case of spontaneous regression of gastric gastrinoma.

CASE SUMMARY

A 37-year-old man with a 9-year history of chronic abdominal pain was referred for evaluation of an 8 cm mass in the lesser omentum discovered incidentally on abdominal computed tomography. The tumor was diagnosed as grade 2 neuroendocrine neoplasm (NEN) on endoscopic ultrasound-guided fine-needle aspiration. Screening esophagogastroduodenoscopy revealed a 7 mm red polypoid lesion with central depression in the gastric antrum, also confirmed to be a grade 2 NEN. Laparoscopic removal of the abdominal mass confirmed it to be a metastatic gastrinoma lesion. The gastric lesion was subsequently diagnosed as primary gastric gastrinoma. Three months later, the gastric lesion had disappeared without treatment. The patient remains symptom-free with normal fasting serum gastrin and no recurrence of gastrinoma during 36 mo of follow-up.

CONCLUSION

Gastric gastrinoma may arise as a polypoid lesion in the gastric antrum. Spontaneous regression can rarely occur after biopsy.

Lesser Omental Panniculitis

A 44-year-old woman presented to our hospital with abdominal pain. Abdominal ultrasonography and computed tomography showed a mass-like change in the lesser omentum between the liver and stomach. Esophagogastroduodenoscopy revealed a submucosal tumor-like change, and endoscopic ultrasonography (EUS) revealed that the mass was located outside of the stomach wall. We performed EUS fine-needle aspiration and diagnosed panniculitis of the lesser omentum. Based on these findings, we suggest that mass-like lesions in the lesser omentum and submucosal tumor-like changes in the anterior wall on the lesser curvature side of the stomach be evaluated for the possibility of panniculitis of the lesser omentum.

Greater Omentum Imaging-Reporting and Data System: establishing the grade of benign and malignant lesions of the greater omentum using ultrasonography

OBJECTIVE

To establish Greater Omentum Imaging-Reporting and Data System (GOI-RADS) to evaluate the possibility of omental diseases being malignant.

METHOD

A retrospective analysis was made of 883 patients who had undergone biopsy of the greater omentum in our center from October 2009 to October 2019. Twelve parameters of ultrasonographic images were evaluated, and the odds ratio of each group calculated. We assigned scores for the direct signs (omental echo, omental structure, and omental nodules) and indirect signs (separation of ascites, echo of ascites, mesenteric lymph nodes, and thickening of parietal peritoneum) of omental lesions. We created an omental score (OS) for each patient and receiver operating characteristic (ROC) curve to analyze its effectiveness in the differential diagnosis of benign and malignant omental diseases.

RESULTS

The OS was divided into ≤5, 6, 7, 8, 9, 10, 11, 12, 13, and ≥ 14 points, and the malignant rate was 0, 1.85, 5.56, 30.36, 37.25, 87.72, 96.72, 98.28, 99.08, and 100%, respectively. The area under the ROC curve (AUC) was 0.976. When taking 10 points as the cutoff value to diagnose benign and malignant omental diseases, the sensitivity and specificity was 93.85 and 98.21%, respectively. A grading system was established: grade 1: omental score ≤ 5, malignant rate 0%; grade 2: omental score 6-7, malignant rate ≤ 5.56%; grade 3: omental score 8--9, malignant rate ≤ 37.25%; grade 4: omental score ≥ 10, malignant rate ≥ 87.72.

CONCLUSION

GOI-RADS had high sensitivity and specificity in the differential diagnosis of benign and malignant omental lesions. We believe that GOI-RADS will aid the diagnosis of omental diseases based on objective and accurate interpretation of ultrasound features, and also to promote the ultrasonography of omental diseases in clinical application.

Integration of proteomics with CT-based qualitative and radiomic features in high-grade serous ovarian cancer patients: an exploratory analysis

OBJECTIVES

To investigate the association between CT imaging traits and texture metrics with proteomic data in patients with high-grade serous ovarian cancer (HGSOC).

METHODS

This retrospective, hypothesis-generating study included 20 patients with HGSOC prior to primary cytoreductive surgery. Two readers independently assessed the contrast-enhanced computed tomography (CT) images and extracted 33 imaging traits, with a third reader adjudicating in the event of a disagreement. In addition, all sites of suspected HGSOC were manually segmented texture features which were computed from each tumor site. Three texture features that represented intra- and inter-site tumor heterogeneity were used for analysis. An integrated analysis of transcriptomic and proteomic data identified proteins with conserved expression between primary tumor sites and metastasis. Correlations between protein abundance and various CT imaging traits and texture features were assessed using the Kendall tau rank correlation coefficient and the Mann-Whitney U test, whereas the area under the receiver operating characteristic curve (AUC) was reported as a metric of the strength and the direction of the association. P values < 0.05 were considered significant.

RESULTS

Four proteins were associated with CT-based imaging traits, with the strongest correlation observed between the CRIP2 protein and disease in the mesentery (p < 0.001, AUC = 0.05). The abundance of three proteins was associated with texture features that represented intra-and inter-site tumor heterogeneity, with the strongest negative correlation between the CKB protein and cluster dissimilarity (p = 0.047, τ = 0.326).

CONCLUSION

This study provides the first insights into the potential associations between standard-of-care CT imaging traits and texture measures of intra- and inter-site heterogeneity, and the abundance of several proteins.

KEY POINTS

• CT-based texture features of intra- and inter-site tumor heterogeneity correlate with the abundance of several proteins in patients with HGSOC. • CT imaging traits correlate with protein abundance in patients with HGSOC.

Schwannoma in the hepatoduodenal ligament with portal vein invasion: A case report

RATIONALE

Schwannomas are mesenchymal tumors with low malignant potential that originate from Schwann cells. They can occur in most parts of the body, such as the head, neck, and extremities. Schwannoma in the hepatoduodenal ligament is extremely rare, and only four cases have been reported in the literature.

PATIENT CONCERNS

Herein, we describe a 58-year-old female who presented with right epigastric pain for 10 days. Preoperative computed tomographic (CT) revealed a 4.5 cm × 3.8 cm tumor in the hepatic hilar area.

DIAGNOSES

Schwannoma in the hepatoduodenal ligament with portal vein invasion.

INTERVENTIONS

Intraoperative findings revealed that the tumor was identified in the hepatoduodenal ligament, and the left branch of the portal vein was compressed. Complete tumor resection with reparation of the portal vein was performed for the patient. Postoperative pathological examination confirmed the final diagnosis of benign schwannoma, characterized by abundant spindle-shaped cells and positive reactivity for S-100 protein.

OUTCOMES

The patient had a good prognosis and had no recurrence after 37 months of follow-up.

LESSONS

Our case of schwannoma in the hepatoduodenal ligament is unique owing to the portal vein invasion, aimed at helping recognize the difficulty of preoperative diagnosis.

"Tethered Fat Sign": The Sonographic Sign of Omental Infarction

Our purpose is to describe the ultrasound sign for a correct non-invasive diagnosis of omental infarction in children. From January 2014 to December 2018, a total of 234 children (109 boys and 125 girls, age range 3-15 y) with acute right-sided abdominal pain, admitted to our hospital with a presumptive diagnosis of acute appendicitis, were prospectively evaluated. In all patients, abdominal ultrasound was performed, and the omental fat was always evaluated. In 228 patients, the omental fat resulted to be normal or hyperechogenic, never tethered, and they results affected by other causes of abdominal pain different from omental infarction (such as appendicitis, pancreatitis, urolithiasis and others). In the remaining 6 children, we found a hyperechoic mass between the anterior abdominal wall and the ascending or transverse colon in the right abdomen quadrant, suggesting the diagnosis of omental infarction. This subhepatic mass was always tethered to the abdominal wall, motionless during respiratory excursions. We named this finding the "tethered fat sign." The diagnosis was confirmed with laparoscopy in 4 children. The other 2 children were treated with conservative therapy. In these 2 patients, a sonographic follow-up was performed, showing a progressive reduction in size of the right-sided hyperechoic mass. In conclusion, our study suggests that the presence of the "tethered fat sign" may be an accurate sonographic sign for non-invasive diagnosis of omental infarction in children.

Capillary hemangioma arising from the lesser omentum in an adult: A case report

RATIONALE

Although capillary hemangiomas, common lesions involving the proliferation of small capillary vessels and a single layer of endothelial cells, can arise in any organ, they are rarely reported in the greater or lesser omentum. Here in, we report a case of capillary hemangioma arising from the lesser omentum in an adult with interesting diagnostic imaging findings, including changes in tumor size over time on computed tomography (CT), that was resected using laparoscopic surgery. To our knowledge, this is the first English report to describe a capillary hemangioma arising from the lesser omentum.

PATIENT CONCERNS

A 63-year-old Japanese man received hemodialysis for chronic renal failure due to diabetic nephropathy, and a small, gradually enlarging tissue mass was found near the lesser curvature of the stomach on plain CT performed annually, without any associated complaints. Diagnostic imaging revealed an 18 × 15-mm tumor with a homogenous, highly enhanced effect in the early phase that was attenuated but prolonged in the delayed phase. Magnetic resonance imaging showed a mass with low signal intensity on T1-weighted imaging and relatively high signal intensity on T2-weighted imaging.

DIAGNOSIS

The patient was diagnosed with capillary hemangioma arising from the lesser omentum according to the pathological and immunohistological findings.

INTERVENTIONS

The patient underwent laparoscopy for excision of the tumor from the lesser omentum.

OUTCOMES

At the 1 year follow-up, the patient had no recurrence of the tumor.

LESSONS

We describe the first case worldwide of capillary hemangioma that was a true vascular tumor arising from the lesser omentum. Although capillary hemangioma arising from the lesser omentum is extremely rare, it should be considered in the differential diagnosis of patients presenting with a highly enhanced lesser omental tumor, and laparoscopy can be safely applied for the excision of this tumor.

A rare diagnosis of abdominal pain presentation in the emergency department: Idiopathic omental bleeding: A case report

RATIONALE

Idiopathic omental bleeding is a rare cause of acute abdomen, with only a few reported cases. It usually presents with abdominal pain and may be life-threatening. As it rarely occurs, it may not be considered initially during patient presentation.

PATIENT CONCERNS

A 35-year-old male came to our emergency department with abdominal pain present for around 5 to 6 hours. The patient complained of left upper quadrant abdominal pain after eating breakfast. The only associated symptom was 3 episodes of vomiting up food. Physical examination revealed mild left upper quadrant abdominal tenderness without muscle guarding or rebounding pain. Blood examination showed leukocytosis with neutrophil predominance and C reactive protein elevation. The pain was persistent and relief was not obtained by medication.

DIAGNOSES

Computed tomography showed a large lobular-contour homogenous slightly hyperdense lesion without enhancement along the greater curvature of the stomach in the lesser sac. A surgeon was consulted and laparotomy was suggested. Hematoma was found at Morrison pouch, subsplenic fossa, and lesser sac under operation.

INTERVENTION

Laparotomy and ligation for hemostasis.

OUTCOMES

The patient was discharged with stable condition after 7 days of hospitalization.

LESSONS

This diagnosis should be considered in patients presenting with epigastric pain and vomiting after eating while in the emergency department because this disease might be life-threatening. This case highlights 2 important learning points. First, idiopathic omental bleeding could occur after eating in patients without underlying disease or trauma history, and this disease should be taken into consideration when acute abdomen occurs. Second, emergent laparotomy is indicated if the cause of acute abdomen is not clear.

Cystic lymphangioma of the lesser omentum in a pregnant woman: a case report and review of the literature

Lymphangiomas are rare benign tumors which are generally seen in pediatric population and the etiopathogenesis has not yet been understood. They occasionally occur in the head and neck or axillary region with only 5% of them being located in the abdominal or mediastinal cavity. These tumors may be asymptomatic or may cause acute abdominal symptoms due to the location and extention. In the English literature, only 4 cases of lymphangioma were reported to have occurred in the pregnancy period. Herein, we report a case of cystic lymphangioma of the lesser omentum detected incidentally on the ultrasonogram of a 21 year-old, 26-week pregnant woman. The patient was followed up uneventfully during pregnancy. Caesarean section was performed due to transverse presentation of the fetus, and the tumor was completely resected during the same session. The patient is recurrence-free after 1 year of postoperative follow-up.

Monophasic synovial sarcoma of the greater omentum: case report and review of literature

Synovial sarcoma is a malignant spindle cell neoplasm normally arising from tissues around joints, bursa and tendon sheaths. Several reports involving the gastrointestinal tract, mainly the oesophagus and stomach, have been documented; however, the omentum remains an extremely unusual location. Monophasic type is composed exclusively of spindle cells arranged in fascicles. Establishing the correct diagnosis of these tumours could be challenging because of the similarities with gastrointestinal stromal tumours and other mesenchymal tumours with similar histology.

Omental torsion: an infrequent cause of abdominal pain

Omental torsion is an infrecuent cause of acute abdomen. It is related to obesity, abdominal surgery and abdominal trauma. Urgent exploratory laparotomy allows diagnosis and prevents complications as intrabdominal abcess. We present CT imaging of a Omenat torsion clinical case.

[A Surgical Case of Solitary Fibrous Tumor Originating from the Greater Omentum]

A36 -year-old man with intellectual disabilities consulted a local physician complaining of a cough, and an abdominal mass was observed on palpation. The patient visited our hospital for close examination. Abdominal contrasting CT revealed a mass with a clear boundary with heterogeneous contrast on the left side of his abdominal cavity. We performed a laparotomy and observed that the tumor originated from the greater omentum. The tumor size was 9×8×6 cm and its weight was 200 g. Histopathologic examination showed hyperplastic spindle-shaped tumor cells with less nuclear fission. Immunohistochemical staining showed that the tumor was positive for CD34, CD99, and bcl-2, slightly positive for p53, and negative for S-100, a- SMA, c-kit, and desmin. Based on the results, a diagnosis of solitary fibrous tumor (SFT) was made. The patient has not shown any recurrence 8 months after surgery.

Omental Infarction In A Child

Omental infarction is a rare cause of acute abdomen in children. Typical findings on imaging establish the diagnosis. We present case of a 7 years old boy who presented with acute right iliac fossa pain with diagnosis of omental infarction on imaging and findings confirmed on laparotomy. Sound knowledge regarding this infrequent cause of acute abdomen in children is necessary for timely diagnosis.

Sclerosing mesenteric panniculitis in a young patient : common cause of diagnostic dilemma and treatment refractoriness

BACKGROUND

Sclerosing mesenteric panniculitis (SMP) is an idiopathic chronic fibroinflammatory disorder of the intra-abdominal fat.

CASE PRESENTATION

Herin, we report a case of SMP, involving the omentum, mesentery and peri-colic fat in a 18 year old male, who presented with significant and recurrent abdominal distension for 4.5 years. Computed tomogram revealed ascites, with nodular and irregular omental thickening and foci of calcification. Non-specific radiological and histological features made an accurate diagnosis extremely difficult. After a thorough work up and exclusion of other differentials, diagnosis of a nodular SMP (Weber Christian disease) was given. After showing resistance to chemotherapeutic agents, slow response was noted with cyclophosphamide, followed by rapid symptomatic improvement with mesenterectomy.

CONCLUSION

SMP is an uncommon benign mesenteric/ omental inflammation, and is a diagnosis of exclusion. As treatment refractoriness is common, management should be individualized and continued for along period. Surgical omentectomy may be helpful.

ILEAL HERNIATION THROUGH THE FORAMEN OF WINSLOW: OVEREATING AS A RISK FACTOR FOR INTERNAL HERNIATION

Internal hernias have an overall incidence of less than 1% and are difficult to diagnose clinically due to their nonspecific presentation. Most internal hernias present as strangulating closed-loop obstruction and delay in surgical intervention is responsible for a high mortality rate (49%). We present a case of ileal herniation through the foramen of Winslow. A 29-year-old previously healthy female presented with acute onset right upper quadrant pain, abdominal fullness, and nausea. The pain was sudden in onset and began shortly after a dinner party where she consumed larger portions of food. Laboratory investigations revealed mild leukocytosis with left shift. Dual-phase multi-detector computed tomography disclosed herniation of the small bowel into the lesser sac. The patient underwent an emergency median laparotomy that revealed ileal herniation through the foramen of Winslow. Adhesiolysis and manual reduction of the bowel was performed, and the reduced bowel showed only congestive changes. The postoperative recovery was uneventful and the patient was discharged on the third postoperative day. Risk factors for internal herniation still remain unclear, although excessively mobile bowel loops and an enlarged foramen of Winslow have been described. Our case demonstrated that overeating could be an additional risk factor for internal herniation. We describe our clinical and radiology findings, as well as surgical management. Due to the high rates of morbidity and mortality, it is imperative that clinicians be aware of the possible risks factors for internal herniation. Internal hernias should be included in the differential diagnosis of small bowel obstruction so that appropriate steps can be made in the work-up of these patients, followed by timely surgical intervention.

Growing teratoma syndrome after ovarian inmature teratoma: a case report and review of the literature

Growing teratoma syndrome is an uncommon complication of malignant germ cell cancer, characterised by the development of large tumours during or after chemotherapy, despite normalisation of tumour marker levels and metastasis, which contain only mature teratoma. Given its low incidence, little is data available. The authors present the case of a 15-year-old girl with a growing teratoma and the literature review outlines the current knowledge of its pathogenesis, common sites, diagnosis, natural course, treatment, and prognosis.

EGIST of the greater omentum - case study and review of literature

The development of immunohistochemical methods has outlined a particular group of tumors, with very specific features and treatment, originating in the Cajal cells of the muscularis propria or related stem cell-like precursors present in the wall of the digestive tract called gastrointestinal stromal tumors (GISTs). A sub-segment with similar features may develop outside the digestive tract, namely extra-gastrointestinal stromal tumors (EGISTs). From the small category of EGISTs, we report on a case of a primary epithelioid EGIST of the greater omentum, which is seldom reported in literature. The tumor was diagnosed in a man with non-specific symptoms who presented for abdominal enlargement. The tumor was characterized and there was a preoperative suspicion of a non-digestive tumor located in the greater omentum. The tumor was surgically removed showing no contact with adjacent organs. Immunohistochemical examination was consistent with a primary EGIST of the greater omentum. Treatment with Imatinib mesylate was started and at two-year follow-up, the patient is disease free. The case raises problems regarding pathogenesis, immunohistochemical features, behavior, evolution and prognosis of omental EGIST, for which no significant or conflicting data are available in the literature.

[Primary omental torsion in preschool girls case report]

INTRODUCTION

Primary omental torsion is a rare finding in cases of suspected acute abdomen. It is more common in children. Secondary omental torsion is typical for adults.

CASE REPORT

The authors describe two cases where pain in the right upper abdominal quadrant was caused by primary torsion of the omental corner due to increased intraabdominal pressure: after a strong cough in one girl and after a workout in the other. Primary omental torsion usually mimics acute appendicitis with clinical findings in the right lower abdominal quadrant, especially in obese children. However, our two cases describe normosthenic girls with pain in the right upper abdominal quadrant up to the mesogastrium.

CONCLUSION

Primary torsion of the omentum is a very rare cause of acute abdomen, which is also confirmed by its incidence in our group of patients where only two cases were seen during a 15-year period, which corresponds to 0.17% of all appendectomies performed in our department. This value is comparable to data reported in the literature.

KEY WORDS

acute abdomen omental torsion tenderness in right upper abdomen.

[Splenosis as a rare cause of abdominal pain]

INTRODUCTION

Splenosis is the autotransplantation of splenic tissue in atypical locations in the abdomen, chest or other parts of the body.

CASE REPORT

Authors present a case of splenosis in a 35 years old woman hospitalized with abdominal pain, who underwent splenectomy for traumatic rupture with splenic tissue implantation in the omentum 19 years ago. Surgical revision was indicated for intensive pain. Histopathology confirmed the diagnosis of splenosis in the excised tissue.

CONCLUSION

Despite the abandonment of splenic tissue autotransplantation after splenectomy, surgeons may still encounter the diagnosis of splenosis in patients after traumatic splenic rupture. Any incidental finding of splenosis during an operation for another indication should be sent for histopathology examination.

KEY WORDS

splenosis, splenectomy abdominal pain scintigraphy.

Case Report of Multimodality Imaging in Omental Cake: Plain Radiograph, Computed Tomography, and Ultrasonography: A Care-Compliant Article

The imaging finding of omental cake has been demonstrated in other modalities, such as computed tomography, magnetic resonance imaging, and ultrasonography. However, to the best of our knowledge, the image presentation of omental cake on a routine kidney-ureter-bladder film has not been reported before in the literature. We presented a unique case of a 61-year-old woman, with known advanced cecal colon mucinous adenocarcinoma, presented to our institution with abdominal fullness, poor appetite, and decreased stool passage for 20 days. Physical examination was unremarkable, except distended abdomen. Subsequent study revealed massive post-pigtail catheter drainage ascites with a prominent soft-tissue mass-causing centralization and tethering of focally distended small bowel gas, suggestive of omental cake on plain radiograph. The imaging finding in plain radiograph corresponds to the findings in other imaging modalities, including abdominal sonography and computed tomography. The patient underwent subtotal colectomy and ileostomy during later courses of chemotherapy due to adhesion ileus and possible intraabdominal abscess, and pathologic study confirmed the diagnosis of cecal mucinous adenocarcinoma and peritoneal carcinomatosis. Although the image finding of omental cake on plain radiograph has never been described, this image finding is unique and should be recognized, as it may suggest the presence of omental cake when first identified in the emergency department from patients with abdominal distension and warrant further evaluation to evaluate the underlying cause.

Extragastrointestinal stromal tumor of lesser omentum: a challenging radiological and histological diagnosis

Extragastrointestinal stromal tumors (EGISTs) are a rare subgroup of gastrointestinal stromal tumors (GISTs), arising from outside the walls of gastrointestinal tubular organs. We report a case of an EGIST of the lesser omentum that represented a diagnostic challenge. Due to its atypical radiologic findings, it was preoperatively mistaken for pedunculated hepatic hemangioma. Histopathologically, it showed epithelioid structure and c-kit negative, very uncommon for GIST. Only a few cases of EGISTs have been previously reported. We discuss imaging and histological features, emphasizing potential pitfalls.

Tubo-omental ectopic pregnancy

Tubo-omental pregnancy is a very rare form of ectopic pregnancy. Here we present a case of tubo-omental pregnancy diagnosed at surgical exploration. A 26-year-old woman presented with abdominal discomfort, nausea and vomiting. There was ectopic pregnancy with viable foetus in the right adnexa and haemoperitonium. Laparotomy was performed and on exploration tubo-omental pregnancy was found attached to fimbria at one side and omentum at the other. Fimriaectomy and partial omentectomy was performed. The patient had a successful post-operative recovery.

Primary omental gastrointestinal stromal tumour (GIST) presenting with a large abdominal mass and spontaneous haemoperitoneum

A 60-year-old Indonesian woman presented with a 9-day history of increasing abdominal distension, pain and tiredness. Physical examination revealed significant pallor with a palpable mass in the abdomen. CT of the abdomen reported a 22 cm complex mass in the peritoneal cavity with free intra-abdominal fluid. Laboratory results showed anaemia with a raised serum CA 125 level. At laparotomy a large haemorrhagic tumour with blood filled cystic cavities was found attached to both greater omentum and the transverse mesocolon with 2.2 L of blood in the peritoneal cavity. There was no invasion of any part of the stomach or intestines and there were no metastases seen. Histopathology of the resected specimen was consistent with that of a gastrointestinal stromal tumour arising from the omentum. Immunohistochemical studies revealed the tumour to be strongly positive for discovered on GIST-1 (DOG1) but negative for both CD117 and CD34. Platelet-derived growth factor receptor α (PDGFRA) exon 18 mutation D842V was detected.

Rare case of omentum-wrapped abscess caused by a fish bone penetrating the terminal ileum

Accidentally ingested foreign bodies, for the most part, pass through the gastrointestinal tract, but can cause several complications. Perforation is rare, but can occur in any segment of the gastrointestinal tract. Intestinal perforations due to foreign bodies are rarely diagnosed preoperatively as clinical symptoms are non-specific and they can mimic other abdominal conditions. We describe a case of a 48-year-old patient who was admitted to the emergency room because of severe abdominal pain of 5 d duration. A computed tomography scan showed an undefined liquid collection involving a linear image 35 mm in size, suggestive of a foreign body. On laparotomy, an abscess containing a fish bone was resected. As fish bone ingestion is usually not remembered by the patient, the diagnosis can be delayed. The preoperative diagnosis is frequently acute abdomen of unknown cause. A low threshold of suspicion along with a good clinical history and radiological studies are extremely important in order to make a correct diagnosis.

18F-FDG PET imaging in a patient with late omental infarction after treatment of pancreatic adenocarcinoma

We report a case of late omental infarction visualized by F-FDG PET/CT during follow-up for pancreatic adenocarcinoma. The 65-year-old patient was referred for imaging 8 months after pancreaticoduodenectomy and 2 months after completion of a course of chemotherapy. PET/CT showed an FDG-avid omental lesion that suggested peritoneal carcinomatosis. The appearance and evolution at follow-up studies confirmed the diagnosis of omental infarction, a rare complication of pancreatic surgery. This case revealed the possibility of late FDG uptake in omental infarction.