Lesser Omental Infarction: Clinical Insights and Diagnostic Challenges in a Rare Case of Acute Abdominal Pain.

Intraperitoneal focal fat infarction (IFFI) is a rare condition characterized by infarction of fatty tissue within the abdominal cavity. Lesser omental infarction, a relatively rare type of IFFI, occurs when there is an infarction of fat within the lesser omentum. Patients typically present with acute abdominal pain that can mimic more serious conditions. This case report highlights the clinical presentation, diagnostic challenges, and management strategies for patients presenting to the emergency department with lesser omental infarction. A 63-year-old female presented to the emergency department with a chief complaint of epigastric abdominal pain that had been persisting for approximately a week and a half. The pain, which initially seemed like a sore muscle, became increasingly sharp and intermittent, with tenderness upon palpation of the epigastric area. Computed tomography (CT) imaging revealed an omental infarct in the lesser sac with focal inflammation in the fat of the lesser omentum. Through conservative management with analgesics and anti-inflammatory medication, the patient experienced resolution of her symptoms within a few days and had a follow-up with the gastrointestinal team several weeks later. Lesser omental infarction typically results from compromised blood flow due to torsion or thrombosis, leading to ischemia and necrosis of the fatty tissue. CT imaging is crucial for its diagnosis and reveals fat-density lesions with surrounding inflammatory changes. Conservative management is typically effective, though in rare cases, surgical intervention may be necessary when significant vital signs and electrolyte derangements occur.

Multiple calcifying fibrous tumors from gastric and retroperitoneal tissue: A case report.

INTRODUCTION AND IMPORTANCE: Calcifying fibrous tumor (CFT) is a rare benign mesenchymal lesion that has been occurred in the gastrointestinal tract, especially occurs most commonly in the stomach and the small and large intestines. CASE PRESENTATION: 74-year-old woman was admitted to our hospital with complaints of epigastric discomfort. Whole-body computed tomography (CT) revealed a 2.2-cm mass with a 1.2-cm low-density area at the anterior wall in the gastric cardia and lesser omentum; however, no abnormal uptake at the same site was noted on positron emission tomography (PET). We performed laparoscopic tumor resection of the two sites. The postoperative course was good without complications. Histopathological findings revealed collagen fibrous granulation connective tissue and psammomatous calcification. Subsequently, the patient has been relapse-free for 6 months. CLINICAL DISCUSSION: CFT is a rare benign tumor that commonly occurs in soft tissues, such as the subcutaneous extremities and neck. In particular, development from the stomach and lesser omentum has never been reported. Our case was incidentally found on a general examination. In our case, CT showed a low-density area, MRI showed a low-intensity area, and PET examination showed no uptake; it was difficult to establish a preoperative diagnosis. Therefore, in our case, laparoscopic tumor resection was performed, with GIST as the differential diagnosis. CONCLUSIONS: We herein reported a rare gastric and lesser omentum CFT that was successfully treated by laparoscopic surgery. For curative treatment of CFT, complete surgical resection is necessary.

Morphological differences between the lesser and the greater omenta in albino rats.

BACKGROUND: Publications report that all mammals have two omenta, namely, lesser omentum and greater omentum. Basically, these organs, which share the same name except for the adjective "lesser" or "greater," should not differ from each other. However, no clear description of the structure of the lesser omentum, as well as comparative morphological analysis between the lesser and greater omenta have been found in the literature, which necessitates a thorough investigation. Therefore, the aim of our study was to analyze the morphofunctional differences between the greater and lesser omenta in albino rats. METHOD: The experiment involved 20 mature male albino rats, weighing 298,28±7,36 grams. The material for our study were preparations of lesser and greater omenta, fixed in 10 % of neutral buffered formalin. Paraffin sections were stained with hematoxylin-eosin and Van Gieson stain. RESULTS: The findings of the study showed that the greater omentum in albino rats, unlike other derivatives of the omentum (ligaments and mesenteries), represents a free extension (mostly from the greater curvature of the stomach), in the form of an "apron," into a specific depth of the peritoneal cavity, duplicating the serous membrane. This duplication is characterized by the composition of two structurally interdependent formations. These include vascular-fatty arcades, associated with lymphoid nodules known as milky spots, and binding serous-reticular membranes. The findings of the study of the lesser omentum have established that in all cases it is located beneath the liver and becomes visualized only after hepatolifting. It is presented in the form of two ligaments: hepatoduodenal and hepatogastric, which contain two main structured formations, which we called vascular-fatty spurs, between these spurs, serous-reticular membranes are located. CONCLUSION: despite having similar names, the lesser omentum, a derivative of the peritoneum, is fundamentally different. As it is well known, the lesser omentum is represented by ligaments that extend from the liver hilus to the lesser curvature of the stomach and the duodenum. Due to this arrangement, the lesser omentum lacks the mobile activity characteristic of the greater omentum, which plays a crucial role in rapid response to damage in the gastrointestinal tract. Despite sharing the same names, both formations differ in shape, morphological structure, development and function.

Cystic lymphangioma of the lesser omentum in an adult patient.

INTRODUCTION: Lymphangiomas belong to the group of benign vascular tumors that originate in the lymphatic tissue. Up to 90% of cases manifest in children before the second year of life. In adults, their presence is very rare. In most cases, they are located in the head, neck and axilla. Intra-abdominal lymphangiomas are very rare and represent less than 1% of all cases. CASE REPORT: The authors present the case of a 64-year-old female patient diagnosed with an intra-abdominal cystic lesion following a routine examination. A CT scan of the abdomen confirmed a cystic lesion located in the lesser omentum between the left lobe of the liver and the lesser curvature of the stomach. The patient was scheduled for laparoscopic exstirpation of the lesion. Histological examination confirmed the clinical diagnosis of cystic lymphangioma of the lesser omentum. CONCLUSION: The etiopathogenesis of lymphangiomas remains unclear. Despite the fact that they are benign tumors, lymphangiomas tend to have an infiltrative pattern of growth, invading surrounding structures. The majority of cases are asymptomatic and the diagnosis is incidental. The gold standard in treatment remains complete surgical extirpation with microscopically negative margins.

Hiatal Hernia of Stomach and Lesser Omentum in a Cadaver: Is It a Type III or IV?

Hiatal hernias, protrusions of abdominal viscera through the esophageal hiatus, are classified into four types. Types I and II involve ascent of the stomach without affecting the gastroesophageal junction. Types III and IV involve the gastroesophageal junction. Type IV specifically may have stomach as well as other abdominal organ involvement, such as pancreas or omentum. Among these types, type IV is the most complex and rare form, accounting for only 0.1% of all cases of hiatal hernias. This report presents a case of a type IV hiatal hernia involving the lesser omentum and a significant portion of the stomach in an 86-year-old male cadaver with a history of mediastinal surgery. To our knowledge, this presentation in a cadaver has not previously been reported in the literature.  This case highlights classification inconsistencies in the literature, particularly regarding type IV hiatal hernias. It is unclear given the current classification system, whether this presentation would be considered a type III or type IV hiatal hernia as it fits both criteria and there are several interpretations of the criteria of a type IV hiatal hernia. Inconsistencies in the classification system may impede standardization of care. This report highlights the need for a more precise classification system that better accounts for anatomical changes and clinical presentation.

Extra-gastrointestinal stromal tumour of the lesser omentum presenting as a massive intra-abdominal swelling: A case report and literature review.

Extra gastrointestinal stromal tumour(EGIST) is rare and is regarded as gastrointestinal stromal tumour(GIST) that originates outside of the gastrointestinal tract. They originate from other intraabdominal tissues such as the omentum, mesentery and peritoneum. The cell of origin is the interstitial cell of Cajal(ICC), a pacemaker cell that controls gastrointestinal peristalsis and the tumor is characterized by the expression of KIT(CD117) a transmembrane tyrosine kinase receptor. Here, a 49-year-old female who presented with a 6 month history of abdominal pain, progressive abdominal swelling and the presence of an upper abdominal mass. She had surgical resection and adjuvant imatinib for the intraabdominal mass diagnosed on histology and immunohistochemistry as EGIST of the lesser omentum. Serial CT 14 months after surgery revealed no evidence of recurrence or metastasis. Clinicians should consider EGIST in the differential diagnosis of abdominal masses.

Spontaneous lesser omental herniation resolved by laparoscopic surgery: case report and systematic literature review.

BACKGROUND: Despite its extremely low incidence, intra-abdominal herniation through the lesser omentum is associated with a high mortality rate and must be recognized early and treated urgently. To overcome a lack of data on the management of this condition, we collected and reviewed all the reported cases of operated lesser omental hernia and presented the case of a patient treated by laparoscopy for an isolated lesser omental hernia. METHODS: According to PRISMA guidelines and using PubMed, Cochrane Library, and Web of Science, a systematic literature review of cases of lesser omental hernia treated by surgery was performed on February 12, 2023. RESULTS: Of 482 articles, 30 were included for analysis and only 9 articles presented an isolated hernia through the lesser omentum. Among these, 4 patients were female and the median age was 38. Upper abdominal pain and vomiting were reported in 7 out of 9 patients. The small bowel was responsible for 78% (7/9) of all lesser omental herniations. All of them were treated by laparotomy. In addition, we describe the case of a 65-year-old woman without prior surgical history who was treated by laparoscopy for a spontaneous closed loop hernia through the lesser omentum without any other associated hernias. CONCLUSION: Mostly associated with prior surgery or trauma, this type of herniation could sometimes occur spontaneously without any sign of peritonitis. Due to the high mortality rate, internal abdominal hernias should always be ruled out with a CT scan in front of patients presenting with persisting acute abdominal pain and no alternative diagnosis.

Lesser omental hernia through a defect in the posterior layer of the lesser omentum.

BACKGROUND: In previously reported cases of lesser omental hernia, a rare clinical presentation, the herniated intestinal tract was passing through both peritoneal layers of the lesser omentum to herniate into the peritoneal cavity or bursa omentalis. Here we present a very rare case of lesser omentum hernia, where the transverse colon entered through only the posterior layer of the lesser omentum to form a hernia between the anterior and posterior layers. CASE PRESENTATION: A 43-year-old man was admitted to the emergency department with acute abdominal pain. Plain abdominal computed tomography (CT) revealed a change in the caliber of the transverse colon between the stomach and pancreas, forming a closed loop on the cephaloventral side of the stomach. On contrast-enhanced CT images, vessels were observed in the contrast-enhanced lesser omentum surrounding the herniated intestine. The patient was diagnosed with a lesser omental hernia and underwent laparoscopic surgery. Intraoperatively, the transverse colon was covered by the anterior layer of the lesser omentum, and a defect was found in the posterior layer of the lesser omentum on the dorsal side of the stomach. A 2-cm incision was made in the posterior layer of the lesser omentum to widen the small defect. The herniated intestinal section was removed from the hernia sac, and the transverse colon was retained unresected. The postoperative course was uneventful. CONCLUSIONS: As illustrated in this first case of a lesser omental hernia forming between the anterior and posterior layers, characteristic CT findings may play an active role in the diagnosis of this rare presentation.

Lesser omental hernia without intestinal gangrene - Case report.

INTRODUCTION: There are several types of internal hernia. Herniation through the defect in the lesser omentum is extremely rare. Symptoms of this type of hernias may vary a lot and diagnosis is difficult. In this case report a young adult with nonspecific symptoms is diagnosed with an intestinal herniation through the defect in the lesser omentum. CASE PRESENTATION: A 35-year-old man with the history of laparoscopic colectomy presented with abdominal pain but no symptoms of peritonitis or acute bowel obstruction. Abdominal computed tomography (CT) revealed displacement of mesenteric vessels, small intestine and stomach. Intestinal herniation through the lesser omentum was suspected. Laparoscopic reposition of small intestine was performed. The greater curvature of the stomach was sutured to the transverse mesocolon to prevent recurrence of hernia. DISCUSSION: Previous surgery, low body mass index (BMI), absence of adhesions may predispose the lesser omental hernia. Herniating of intestines through the large openings may occur without presence of acute obstruction or gangrene. CT is helpful in making a correct diagnosis. CONCLUSION: When evaluating the patient with abdominal pain, internal hernia should be considered. CT modalities may aid in the detection of these rare hernias and ensure timely treatment. Perioperative inspection and repair of the hepatogastric ligament may help to prevent lesser omental hernias.

Complete enclosure of gall bladder inside the lesser omentum - a rare anomaly.

Gall bladder is known for many congenital anomalies such as duplication, intrahepatic position, floating position etc. Most of its anomalies can be detected in ultrasound examination and radiography. We report an extremely rare congenital anomaly of gall bladder as observed in a male cadaver during dissection classes. The gall bladder was totally enclosed in the right free margin of the lesser omentum, in front of the usual contents of the right free margin of lesser omentum. The size, shape and blood supply of the gall bladder were normal. Though this anomaly might not cause any functional disturbances, it might result in complications during laparoscopic cholecystectomy.

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.

Target region resection in patients undergoing cytoreductive surgery for peritoneal metastases-is it necessary in absence of visible disease?

BACKGROUND: The aim was to study the patterns of target region (greater omentum, lesser omentum, falciform and umbilical round ligament) involvement in patients undergoing cytoreductive surgery (CRS) from various primary tumors, factors affecting involvement and implications on surgical practice. METHODS: All patients undergoing CRS from July 2018 to December 2018 were included in this prospective study. The incidence of target region involvement in presence and absence of visible disease and the impact of primary tumor site, PCI and other variables on target region involvement was evaluated. RESULTS: In 191 patients, greater omentum was involved in over 15% of patients irrespective of the primary tumor type and in 15.7% in absence of visible disease. 75% of these had PCI <20. The involvement of the other three target regions was higher than 20% in ovarian cancer, appendiceal tumors and peritoneal mesothelioma. Involvement of these 3 regions was associated with a higher PCI (p < 0.001 for all) and omental involvement (p < 0.001for all). 2.1% of colorectal cancer patients had umbilical round ligament involvement, 4.2% had falciform ligament involvement and none had lesser omentum involvement. CONCLUSIONS: Target region involvement varies according to primary tumour site and disease extent. Resection of the greater omentum should be performed during CRS for PM arising from all primary sites. Resection of other target organs may be performed for selected patients with ovarian cancer, peritoneal mesothelioma and mucinous appendiceal tumors in absence of visible disease. For other patients, it should be done only in presence of visible disease.

Lesser omental panniculitis: a possible cause of acute abdomen.

We encountered a case of panniculitis of the lesser omentum in 2018 after a long time since our first case report in 2007. We reviewed previously reported three cases of lesser omental panniculitis including our first case to investigate its clinical characteristics. Total four cases were relatively young with mean age of 30, and had common chief complaint of considerable epigastric pain and tenderness. Blood test showed increase in the white blood cell, C-reactive protein, or erythrocyte sedimentation rate. Computed tomography revealed mass like change in the fat tissue outside of the lesser curvature of the stomach. Histopathological diagnosis was made in one operated patient. Other three patients were treated conservatively, and progressed well. Lesser omental panniculitis is a possible cause of acute abdomen, which shows characteristic images of computed tomography and probably good progress by conservative treatment.

Earlobe-like peritoneal appendage near the angle of His: a useful landmark for demarcating the lateral margin of the gastric cardia.

The gastric cardia-the small area around the cardiac orifice including the abdominal esophagus-is an important target area for abdominal and thoracic surgeries, especially for laparoscopic procedures. In this study of 28 cadavers, a peritoneal earlobe-like appendage near the angle of His was identified as a useful indicator of the lateral margin of the abdominal esophagus, which is otherwise obscure because the peritoneum continues to the diaphragm without definite demarcation of this margin. This structure, which appears equivalent to the epiploic appendages, was commonly found to be present (in 22/28, 78.6 % of the 28 cadavers) and was 4-21 mm × 6-40 mm × 1-4 mm in size, triangular, round, or leaf-like in shape, contained fat, and was on an imaginary line along which the lesser omentum adheres to the lesser curvature and continues to the diaphragm (18/22, 81.8 %). This indicator is associated with the lesser omentum and is part of the gastrophrenic ligament, and could serve as a useful indicator of the margin of the gastric cardia, thus aiding surgeons performing laparoscopic surgery in this region.

Internal herniation through lesser omentum hiatus and gastrocolic ligament with malrotation: a case report.

BACKGROUND: Internal herniation through lesser omentum hiatus and gastrocolic ligament with malrotation is extremely rare. This type of internal hernia has rarely been described before. Preoperative diagnosis is difficult and prone to misdiagnosis. CASE PRESENTATION: A 38-year-old Chinese woman was an emergency admission to our hospital with a sudden onset of acute epigastralgia for the past 14 hours. We made a presumptive diagnosis of gastrointestinal perforation and septic shock. Due to the acute onset and rapid progress, she received timely surgical treatment. During operation, we observed that her small intestine herniated into the hepatogastric ligament and ligamentum gastrocolicum hiatus accompanied with intestinal malrotation that resulted in internal hernia. We found a diverticulum of approximately 3.0 × 6.0 cm sited at a distance of 80 cm from the ileocecal intestine. We resected the strangulated intestinal loop and the diverticulum, performed an appendicectomy, and closed the ligamentous fissure. Postoperation, she recovered smoothly, without any complications, and was discharged on day 6. CONCLUSIONS: A case of internal hernia formation is quite rare; accurate preoperative diagnosis and timely surgery are essential because it can cause strangulation of the ileus. However, the incidence of this internal herniation is low and preoperative diagnosis is difficult. An accurate preoperative diagnosis of internal hernia is still a challenge.

Extragastrointestinal stromal tumour of the lesser omentum: A case report and literature review.

INTRODUCTION: Extragastrointestinal stromal tumours (EGISTs) are very uncommon compared to their gastrointestinal counterparts. Most of them originate from the intestinal mesentery and the omentum. CASE REPORT: A 70 year-old Caucasian woman presented with a bulky abdominal mass which on laparotomy was found to originate from the lesser omentum and was completely resected. Histological examination revealed spindle cells with severe pleomorphism and high mitotic activity. Immunohistochemically, the tumour cells showed strong positivity for c-kit (CD117), DOG-1 and human haematopoietic progenitor cell antigen (CD34). An exon 11 deleterious mutation was identified and thus regular dosing of 400mg imatinib mesylate was initiated. DISCUSSION: There have been only a few previous reports of EGISTs arising in the lesser omentum. Although EGISTs seem to have morphological and immunohistochemical similarities with GISTs, their pathogenesis, incidence, genetic background and prognosis are not completely known because they are extremely rare. It is strongly believed that such tumours originate from cells, which have similar pathological characteristics and biological behaviour as the intestinal cells of Cajal. In most series of EGISTs, a female predominance, a greater size and a higher mitotic index than GISTs were observed. CONCLUSION: EGISTs are very rare mesenchymal tumours which originate from cells outside the gastrointestinal tract and tend to have a more aggressive biological behaviour than their GI counterparts. Complete surgical resection is the most effective treatment associated with the use of imatinib in the presence of adverse prognostic factors. In any case a strict follow-up is necessary due to high recurrence rates.

[The lesser omentum approach for laparoscopic pancreatic enucleation].

Objective: To evaluate the feasibility and strategy of the lesser omentum approach for laparoscopic pancreatic enucleation. Methods: Between June 2011 and October 2013, 6 laparoscopic pancreatic enucleations were performed by lesser omentum approach.The average age was 42 years, including 1 male and 5 female.The preoperation diagnosis of 6 cases were pancreatic islet cell tumors determined by abdominal CT/MRI, ultrasound and digital subtraction angiography.The tumors of 3 cases located in pancreatic neck, 2 tumors located in neck and body of pancreas, and 1 tumor located in pancreatic body.Their biggest tumor diameter were 0.8-2.5 cm. Results: Among the 6 cases, all laparoscopic pancreatic enucleations were successfully performed.None of the patients were converted to open operation.Eestimated blood loss was (26.7±18.6)ml, operating time was (82.5±19.4)minutes, and postoperative length of stay was (5.17±1.17)days.Additionally, postoperative complication included grade A pancreatic fistula in 1 case.After 36-64 months followed-up, there was no tumor recurrence and clinical symptom disappeared. Conclusion: For the islet cell tumors located in pancreatic neck and body, the lesser omentumapproach may contribute to good surgical view and operative space, which can make pancreatectomy safer and easier for clinical application.

The lesser omentum approach for laparoscopic pancreatic enucleation / 中华外科杂志

Objective@#To evaluate the feasibility and strategy of the lesser omentum approach for laparoscopic pancreatic enucleation.@*Methods@#Between June 2011 and October 2013, 6 laparoscopic pancreatic enucleations were performed by lesser omentum approach.The average age was 42 years, including 1 male and 5 female.The preoperation diagnosis of 6 cases were pancreatic islet cell tumors determined by abdominal CT/MRI, ultrasound and digital subtraction angiography.The tumors of 3 cases located in pancreatic neck, 2 tumors located in neck and body of pancreas, and 1 tumor located in pancreatic body.Their biggest tumor diameter were 0.8-2.5 cm.@*Results@#Among the 6 cases, all laparoscopic pancreatic enucleations were successfully performed.None of the patients were converted to open operation.Eestimated blood loss was (26.7±18.6)ml, operating time was (82.5±19.4)minutes, and postoperative length of stay was (5.17±1.17)days.Additionally, postoperative complication included grade A pancreatic fistula in 1 case.After 36-64 months followed-up, there was no tumor recurrence and clinical symptom disappeared.@*Conclusion@#For the islet cell tumors located in pancreatic neck and body, the lesser omentumapproach may contribute to good surgical view and operative space, which can make pancreatectomy safer and easier for clinical application.

Strangulated lesser omentum hiatus hernia: a rare case report and a literature review.

Intestinal obstruction caused by primary intraperitoneal hernia is infrequent and difficult to diagnose. Incorrect diagnosis and delayed surgical treatment will lead to serious consequences. We report a rare case of a 62-year-old Chinese woman with strangulated lesser omentum hiatus hernia. Contrast-enhanced abdominal computed tomography(CT) scan is recommended for early revealing direct and indirect signs. We propose three diagnostic points of primary intraperitoneal hernia: 1. "Three-no" pathography: with no history of abdominal operation, abdominal trauma and abdominal infection. 2. It begins with mechanical intestinal obstruction, then turns into strangulated intestinal obstruction easily. 3. Exclude intestinal wall lesions and intestinal blockage. We also summarize surgical procedure into four steps. We hope this case can provide a reference for the diagnosis and treatment of similar situations.