BACKGROUND: Malignant extrarenal rhabdoid tumor (MERT) is a rare and highly metastatic tumor, which is more than 75% of patients dying within 6 months of initial diagnosis, and it often leads to misdiagnosis and delayed treatment.
METHODS: This paper reports a 16-year-old girl who presented with the chief complaint of acute abdominal pain. She underwent laparoscopic exploration and excisional biopsy, then pathological examination and immunohistochemistry revealed \"extrarenal malignant rhabdomyoma.\" One month after operation, she died of intra-abdominal hemorrhage and multiple organ dysfunction.
CONCLUSIONS: MERT were often misdiagnosed and had a poor prognosis. The surgery and chemotherapy are usually beneficial to prolong the survival time of patients with MERT.

BACKGROUND: The most common causes of scrotal enlargement in patients include primary tumor of the scrotum, inflammation, hydrocele of the tunica vaginalis, and indirect inguinal hernia; scrotal enlargement caused by external tumors of the scrotum is rare. The patient had both a greater omentum tumor and an inguinal hernia, and the tumor protruded into the scrotum through the hernia sac, which is even rarer. Moreover, omental tumors are mostly metastatic, and primary omental fibroma is rare.
METHODS: Here, we report a rare case of a 25-year-old young man with scrotal enlargement and pain for 3 months. Preoperative examination and multidisciplinary discussions considered intra-abdominal tumor displacement and inguinal hernia, and intraoperative exploration confirmed that the greater omentum tumor protruded into the scrotum. Therefore, tumor resection and tension-free inguinal hernia repair were performed. The final diagnosis was benign fibroma of the greater omentum accompanied by an indirect inguinal hernia.
CONCLUSIONS: This unusual presentation of a common inguinal hernia disease illustrates the necessity of performing detailed history taking, physical examination, and imaging before surgery.

Umbilical hernia is a common type of extra-abdominal hernia in adults. However, chronic granulocytic leukemia in combination with cirrhotic ascites and renal insufficiency is less common. The patient reported here had both indications and contraindications for emergency surgery; therefore, the treatment options were subject to debate. We report the case of a man in his 60s who had a strangulated umbilical hernia, with overlying purple-colored infected and necrotic skin. The area was painful, but his bowel movements were normal. Patients underwent comprehensive conservative management, and remote follow-ups via telephone and video conferencing for a period of 60 days, during which the incarcerated contents of the hernia eventually retracted and his pain was relieved, such that there were no longer indications for emergency surgery. In addition, his skin infection disappeared and his quality of life improved, and therefore the treatment outcomes were good. Thus, we provide evidence that not all incarcerated umbilical hernias require emergency surgery, but may respond well to conservative treatment when the contents do not include intestinal loops or other critical organs.

Inflammatory myofibroblastic tumor (IMT) prevalence is less than one in a million. Anaplastic lymphoma kinase (ALK)-positive IMT in the greater omentum and with a diameter greater than 8 cm is extremely rare. Here, we present a case and provide a brief literature review. A 4-year-old female was referred to our hospital with a 1-month history of intermittent fever. Computed tomography revealed a 6.4 × 5.5 × 6.5-cm lesion between the spleen and stomach. During the operation, we confirmed that the mass originated in the greater omentum and completely resected the mass, achieving a negative margin. The maximum cross-sectional area of the tumor after surgery was 8.3 × 7.5 cm. The immunohistochemistry result of this IMT was ALK (+), S100 (-), Ki-67+ (20%), Desmin (+), CD21 (-), CD35 (+), Vim (+), and SMA (+). The final pathology was IMT. No local recurrence or metastasis has been observed in the 8 months of follow-up.

OBJECTIVE: To demonstrate the entire course of the human vitelline vein (VV) in specimens after degeneration of the yolk sac.
METHODS: Sagittal and horizontal histological sections from 8 embryos and 19 fetuses (gestational age approximately 6-12 weeks; crown-rump length 11-61 mm) were examined.
RESULTS: Two types of VV remnants were observed: a long VV on the right superior side of the mesentery of the jejunum (VV1) and a short VV on the left inferior side of the mesentery (VV2). The VV1, observed in 12 specimens, was 20-30 microns in diameter and ran dorsally between the right liver lobe and the jejunum, subsequently merging with an initial superior mesenteric vein on the pancreatic head immediately below the superior portion of the duodenum. The VV2, observed in four specimens, passed dorsally between loops of the ileum on the left side of the mesentery of the ileum and connected to the mesentery. Many of the VVs did not originate from the umbilical cord but suddenly started in the sack of physiological herniation. At 10-12 weeks, after herniation, the VVs originated from the umbilicus and were involved by the expanding greater omentum.
CONCLUSIONS: The right-sided and left-sided VVs seemed to correspond to right and left VV remnants, respectively, and both took an upstream course outside the mesentery of the jejunum and ileum. The right VV upstream portion was likely to disappear later than the left one, but the timing of degeneration varied greatly among individuals, depending on the topographical relationship between the right liver lobe and the jejunum.

BACKGROUND: Drainage tube removal is difficult when the greater omentum becomes incarcerated in the drainage tube through the side holes. Currently, known removal methods are either ineffective or will cause additional damage to the patient in a secondary operation. Ureteroscopy and the holmium laser have been used in various surgical techniques in urology, and in theory, they are expected to be a good strategy for solving the problem of tissue incarceration.
METHODS: Four patients diagnosed with difficult removal of an abdominal drainage tube following abdominal surgery are reported. All patients underwent surgery to remove the incarcerated greater omentum in the drainage tube using a holmium laser and a ureteroscope, and a new 16-F drain was then placed in the abdominal or pelvic cavity. The efficacy of this technique was evaluated by intraoperative conditions, success rate, and operating time; safety was evaluated by perioperative conditions and the probability of postoperative complications. All four operations went smoothly, and the drains were successfully removed in all patients. The average operating time was 24.5 min. Intraoperatively, the average irrigation volume was 892.0 mL, the average drainage volume was 638.5 mL, and no bleeding or damage to surrounding tissues was observed. Postoperatively, the average drainage volume was 32.8 mL and the new drains were removed within 36 h. All patients were able to get out of bed and move around within 12 h. Their visual analogue pain scores were all below 3. The average follow-up duration was 12.5 mo and no complications such as fever or bleeding were noted.
CONCLUSIONS: Ureteroscopic holmium laser surgery is an effective, safe and minimally invasive technique for removing drains where the greater omentum is incarcerated in the abdominal drain.

Although complete omentectomy is traditionally performed in patients with gastric cancer as part of radical gastrectomy to ensure the elimination of micrometastases, the prognostic value of omentectomy during gastrectomy remains unclear. Retrospective studies have shown that the incidence of metastases in the greater omentum is very low in T1-T3 gastric cancer. Thus radical gastrectomy with D2 lymphadenectomy and preservation of the greater omentum may be a proper curative treatment for gastric cancer patients with T1-T3 tumors. The aim of this article is to describe the design and rationale for this prospective, randomized controlled DRAGON-05 trial, conducted to evaluate the prognostic value of omentum-preserving gastrectomy for patients with T1-T3 gastric cancer. Clinical trial registration: ChiCTR2000040045 (ClinicalTrials.gov).

Mesenchymal stem cells (MSCs) have been reported to promote regeneration in both subjects with acute kidney injury (AKI) and chronic kidney disease (CKD), but their efficacy remains limited, probably because most of the cells accumulate in the lungs, liver, and spleen after an intravenous infusion. Therefore, ultrasound-guided administration of MSCs represents a possible approach to solve this problem. The greater omentum is used to promote cell survival due to its rich vasculature. We hypothesized that ultrasound-guided administration of MSCs combined with greater omentum might be more curative than currently available approaches.
In this study, we established an aristolochic acid nephropathy (AAN) model by intraperitoneally administering aristolochic acid I sodium salt (AA-I) at a dose of 5 mg/kg body weight on alternate days for 4 weeks. Subsequently, a laparotomy was performed, and the left kidney from which the capsule had been removed was wrapped with the greater omentum. A dose of 2 × 107 MSCs was injected into the space between the greater omentum and the left kidney. Equal amounts of MSCs were administered under ultrasound guidance every second week for a total of 4 treatments. Mice were sacrificed 4 weeks after surgery. Serum creatinine and blood urea levels were measured to assess renal function. qPCR, Western blot, and histological analyses were conducted to further investigate the therapeutic mechanism of MSCs.
Ultrasound-guided injection of MSCs into the greater omentum that surrounds the kidney enriched cells in the kidney region for up to 5 days. Renal function tests indicated that MSCs improved renal function to a great extent, as reflected by decreased blood urea nitrogen and serum creatinine levels. In addition, histological analyses showed that MSCs noticeably attenuated kidney injury, as evidenced by the amelioration of tubular necrosis and peritubular interstitial fibrosis. Mitigation of renal interstitial fibrosis was further confirmed by immunohistochemistry, qPCR, and western blotting after MSC treatment. Moreover, immunofluorescence staining revealed that MSCs alleviated inflammatory responses by increasing the counts of CD206+ cells and decreasing the counts of CD68+ cells. MSC migration was initiated in response to AA-I-treated renal epithelial cells in an in vitro migration assay.
These findings suggested that administration of MSCs into the cavity formed by the injured kidney and the greater omentum under ultrasound guidance improved renal function, attenuated kidney injury, and mitigated renal interstitial fibrosis and inflammatory responses. Thus, this approach might be a safe and effective therapy for CKD.

BACKGROUND: Leiomyoma of the uterus is relatively common, but uterine leiomyoma of the greater omentum is rare.
METHODS: Here, we report the case of a 22-year-old woman who presented with a 3 mo history of progressive abdominal distension and a hypervascular abdominopelvic mass. Due to a high serum concentration of CA125, the preoperative diagnosis was unclear. During surgery, 5 L of ascites was removed. An 18.8 cm solid mass, which was pedunculated from the uterine fundus and exhibited complex adhesion to the greater omentum, was removed. The CA125 level was reduced postoperatively, and a pathologic study confirmed that the mass was a leiomyoma that originated in the uterus.
CONCLUSIONS: Uterine leiomyoma can share vessels with the greater omentum. This case highlights the difficulty of diagnosing pseudo-Meigs syndrome and the importance of imaging and laboratory examinations.

OBJECTIVE: To investigate whether ultrasound elastography (UE) is an effective non-invasive diagnostic procedure for evaluating benign and malignant thickened greater omentum.
METHODS: Ultrasound elastographic images from 118 patients who underwent ultrasound-guided biopsy for thickened greater omentum from May 2012 to October 2013 were retrospectively analysed. The results were compared with the pathological findings from the biopsies, and evaluated by ROC curve analysis.
RESULTS: A total of 93.6% of the benign thickened greater omentum had elasticity scoring of 1 or 2, whereas 93.0% of the malignant thickened greater omentum had elasticity scoring of 3 or 4. The elasticity strain ratios for malignant thickened greater omenta were higher than for benign thickened greater omenta using muscle or fat yielded as reference tissue (P < 0.01). The optimal cut-off point for elasticity strain ratios using fat as reference was 2.6. The sensitivity, specificity, accuracy, and positive and negative predictive values for determining elasticity strain ratios using fat as reference were 83.3%, 90.6%, 86.5%, 92.1%, and 80.6%, respectively, and for elasticity scoring were 95.2%, 96.9%, 95.9%, 97.6%, and 93.9%, respectively.
CONCLUSIONS: UE using elasticity scoring or elasticity strain ratios is an effective new non-invasive method for differentiating benign from malignant thickened greater omentum.
CONCLUSIONS: • Elasticity score is an objective method for differentiating greater omentum lesions. • Elasticity strain ratio is another method for differentiating greater omentum lesions. • Fat tissue is better than abdominal wall muscle as reference in elasticity imaging. • UE is a new effective, non-invasive method for diagnosing omental diseases.