A Unique Case of Mesenteric Gastrointestinal Stromal Tumor Presenting as an Acute Abdomen.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in the digestive tract and arise from the interstitial cells of Cajal in the mesenteric plexus. These tumors can originate in any part of the GI tract; however, a higher burden has been observed in the stomach and small intestines. Mesenteric GISTs are exceedingly rare, with unique clinicopathological features and a poorer prognosis. Herein, we describe a unique case of a 66-year-old female with a remote history of appendectomy who presented to the emergency room complaining of severe abdominal pain and vomiting. On imaging, the patient was found to have a large inflammatory mass associated with small bowel loops, and the pathology confirmed a mesenteric GIST. The tumor was resected, and the genomic test results confirmed the KIT (exon 11) mutation. Although the tumor had a low mitotic rate, the tumor was large enough to warrant the initiation of adjuvant imatinib mesylate for 36 months with regular bloodwork and imaging.

68 Ga-FAPI-04 PET/CT Imaging of Mesenteric Aggressive Fibromatosis.

ABSTRACT: Aggressive fibromatosis is a relatively rare disease. We describe 68 Ga-FAPI-04 PET/CT findings in a case of histologically proved mesenteric aggressive fibromatosis. 68 Ga-FAPI-04 PET/CT revealed a mass in the mesentery with increased FAPI activity. This case indicates that FAPI PET may be useful for evaluation of aggressive fibromatosis.

Recurrent mucinous cystic neoplasm of the mesentery in a young nullipara mimicking as ovarian carcinoma.

INRODUCTION: Mucinous cystic neoplasms are rare tumors. They may originate from either ovaries, pancreas, or other intra-abdominal sites, but rarely from the mesentery. CASE HISTORY: A 22-year-old nulliparaous woman, who had undergone laparascopic bilateral cystectomy for recurrent ovarian mass, presented with pain in abdomen, backache, and menstrual irregularities. Provisionally diagnosed as ovarian carcinoma, she underwent bilateral salpingo-oophorectomy and sigmoid colectomy. However, the histopathological examination revealed mucinous cystic neoplasm of the mesentery. DISCUSSION: Thus, complete resection of the cysts with meticulous gross and histopathological examination remains the gold standard to differentiate mucinous cystic neoplasm (MCN) of the mesentery from its mimics, especially malignant counterparts, enabling clinicians to adequately manage such patients. Here, we present a case of recurrent MCN of mesentery (mesocolon), mimicking as ovarian carcinoma confirmed on histopathological examination, in a young adult.

A case of significant loss of mesenteric fat: Educational and clinical relevance.

Mesenteric fat, a type of intraperitoneal adipose tissue, plays a critical role in protection and the immune response. Loss of mesenteric fat is a known consequence of a variety of clinical conditions; however, visual documentation of this rare occurrence is not available in the literature searched. Here we report a case of significant loss of mesenteric fat identified during educational dissection of a 79-year-old male fresh frozen donor cadaver, causing the mesenteric folds to appear transparent. The gross anatomical characteristics, clinical importance, and educational significance of this abnormality are described in this report. Knowledge of this condition may be of interest to clinicians, and documentation could benefit anatomists and educators dissecting and teaching in the laboratory setting.

[A Case of Desmoid-Type Fibromatosis of the Mesentery of Small Intestine].

Desmoid-type fibromatosis is a relatively rare disease, often associated with familial adenomatous polyposis and a history of abdominal surgery. A 43-year-old male patient presented with abdominal pain and contrast-enhanced CT showed a mass in the lower abdomen. The mass was a 4×4×3 cm white, dense tumor with a wreath-like arrangement of eosinophilic spindle-shaped cells. Immunostaining showed KIT(-), CD34(-), desmin(-), ß-catenin(+), SMA(few+), and the diagnosis was desmoid-type fibrosis. Six months after surgery, there was no apparent recurrence.

Peritonectomy and resection of mesentery during Visceral-Peritoneal Debulking (VPD) in patients with stage IIIC-IV ovarian cancer: A phase I-II trial.

OBJECTIVE: To describe the surgical technique, assess feasibility, efficacy, and safety of peritonectomy and/or resection of mesentery (P-Rme) during Visceral-Peritoneal Debulking (VPD) in patients with stage IIIC-IV ovarian cancer (OC). METHODS: In April 2009 we registered a protocol study on the safety and feasibility of P-Rme. In the period April 2009-December 2022, 687 patients with FIGO stage IIIC-IV ovarian cancer underwent VPD. One hundred and twenty-nine patients (18.7%) had extensive disease on the mesentery and underwent P-Rme. Feasibility was assessed as the number of procedures completed. Efficacy was measured as the rate of Complete Resection (CR). Safety was defined by the intra- and post-operative morbidity rate specifically associated with these procedures. RESULTS: In all patients P-Rme was successfully completed. P-me was performed in 82 patients and R-me in 47, both procedures in 23 patients. CR was achieved in all 129 patients with an efficacy of 100%. Intra-operatively 5 patients out of 129 experienced small bowel loop surgical devascularization. They required small bowel resection and anastomosis. The procedure specific morbidity was 3.8%. No post-operative complication was related to P-Rme. At 64 months median follow-up, survival outcomes in the study group were similar to patients in the control group. CONCLUSION: Overall, almost 20% of the VPD patients needed P-Rme to obtain a CR. P-Rme was a safe and effective step during VPD. The rate of CR in the study group was 100% achieved thanks to the addition of the P-Rme. No procedure specific post-operative complications occurred but 3.8% of the patients had unplanned additional surgery related to these procedures.

Primary EGIST of the greater omentum - a rare presentation.

Extragastrointestinal stromal tumors (EGISTs) are rare mesenchymal neoplasms, which develop in the retroperitoneum, mesentery, and omentum, lacking continuity to the stomach or intestines. Authors hereby present a female patient with a large heterogeneous abdominal mass as a case of an omental EGIST. A 46-year-old woman was referred to our hospital due to an insidious enlargement and colicky pain in the right iliac fossa. Abdominal palpation revealed a voluminous, freely mobile, and non-pulsatile mesoabdominal bulge expanding to the hypogastrium. On exploratory midline laparotomy, the tumor was densely fused to the greater omentum, not connected to the stomach, without gross involvement of adjacent structures. The large mass was completely excised after adequate mobilization. Immunohistochemical techniques showed strong and diffuse expression of WT1, actin and DOG-1, as well as multifocal c-KIT marking. Mutational study concluded a double mutation of KIT exon 9 and a mutation of PDGFRA exon 18. The patient was submitted to adjuvant treatment with imatinib mesylate 800 mg/day. Despite an extremely diverse presentation, omental EGISTs often remain clinically silent for a long time having enough space to grow before becoming symptomatic. These tumors have a consistent pattern of metastasis that typically spares lymph nodes unlike epithelial gut neoplasms. Surgery remains the preferred treatment for non-metastatic EGISTs of the greater omentum. It is possible that DOG-1 will supplant KIT as the leading marker in the future. The scarcity of knowledge on omental EGISTs implies a close monitoring of these patients to detect local relapse or distant metastasis.

Incidental intra-abdominal synovial sarcoma.

Intra-abdominal synovial sarcomas are a rare type of soft tissue sarcomas that arise in the soft tissues of the abdominal cavity. They account for less than 1% of all primary synovial sarcoma cases. We report a case of a male patient in his early 30s who presented to the hospital with abdominal pain of 2 weeks duration. On examination, a mass was felt in the left mid-abdomen. MRI revealed a 12.7 cm×8.2 cm×8.6 cm soft tissue mass on the mesentery of the jejunum. The patient underwent surgical resection of the tumour, and the final pathology was synovial sarcoma, pT2b, grade 3.

[A Case of Desmoid Fibromatosis of the Small Intestinal Mesentery Institutions].

The patient was a 27-year-old man. He was referred to our hospital because he was aware of a mass in his abdomen. An abdominal ultrasound showed a 70-mm mass lesion. Enhanced computed tomography showed a 70-mm mass with well- defined margins and heterogeneous internal enhancement near the proximal jejunum. The patient was diagnosed with a suspected primary submucosal tumor of the duodenum or small intestine, and surgery was planned to diagnose and treat the tumor. The tumor was located in the upper jejunal mesentery, and tumor resection and partial small bowel resection were performed. Histopathological examination revealed proliferation of spindle-shaped cells without karyomitosis, and mixed collagen fibers in the tissue. Immunohistochemistry showed ß-catenin(+), SMA(+), AE1/AE3(-), KIT(-), CD34(-), and S-100(-). Based on these findings, we diagnosed primary desmoid fibromatosis of the small intestinal mesentery. In this report, we describe a case of primary desmoid fibromatosis of the small intestinal mesentery with a review of the literature.

18 F-FDG PET/CT Findings in Waldenström Macroglobulinemia With Mesentery Involvement.

ABSTRACT: A 74-year-old man presented to the hospital complaining of weight loss, increasing fatigue, and blurred vision. The abdominal ultrasonography initially revealed a massive lesion in the mesentery, which was later confirmed by a contrast-enhanced CT scan. The 18 F-FDG PET/CT scan showed a single, solitary hypermetabolic mass. The patient was finally diagnosed with Waldenström macroglobulinemia with mesentery involvement by the histopathological examination.

Desmoid-type fibromatosis of the mesentery: a clinicopatho-logical and genetic analysis of 9 cases. / è‚ ç³»è†œéŸ§å¸¦æ ·çº¤ç»´ç˜¤ç— æ‚£è€ ä¸´åºŠç— ç†å­¦åˆ†æž.

Nine cases of mesenteric desmoid-type fibromatosis were diagnosed and treated in Taizhou Hospital, Wenzhou Medical University between January 2010 and May 2022, including 2 females and 7 males, aged 16 to 59 years. The lesions were in the mesentery of small intestine with 7 cases, ileocecal junction with 1 cases and transverse colon with 1 case. The tumors had an unclear boundary and no envelope, the section was solid, gray and tough. The mean maximum diameter was (10.7±8.5) cm (range 3.5-33.0 cm). Microscopically, fusiform fibroblasts and myofibroblasts were parallel, bunched or staggered, buried in a large amount of extracellular collagen. The cell morphology was relatively consistent, without obvious atypia, and mitosis was rare. Immunohistochemistry showed that the tumor cells were positive for vimentin (9/9), ß-catenin (9/9), while smooth muscle actin (5/9) stains were focally positive. Ki-67 proliferation index was 1%-10%. Cytokeratin Pan, S-100, STAT6, CD117, DOG1, CD34, desmin and anaplastic lymphoma kinase stains were negative. Genetic analysis showed that there were 7 cases of c.121G>A(p.Thr41Ala) mutation of CTNNB1 gene, 1 case of c.121G>A(p.Thr41Ala) and 1 case of c.134C>T(p.Ser45Phe) double mutation, and 1 case of wild type. Tumors were surgically resected in all 9 cases. Eight cases had no recurrence or metastasis, 1 case had recurrence 6 months later, and no recurrence or metastasis after additional surgical resection.

Laparoscopic surgery for rectal cancer with a coexisting Retzius shunt and inferior mesenteric arteriovenous malformation: A case report.

A coexisting short-circuit from the inferior mesenteric vein (IMV) to the inferior vena cava, known as a Retzius shunt, and arteriovenous malformation (AVM) of the inferior mesentery are extremely rare conditions. We encountered a case of rectal cancer with coexisting Retzius shunt and inferior mesenteric AVM successfully treated with laparoscopic surgery. Contrast computed tomography (CT) in a 62-year-old man with rectal cancer showed multiple dilated veins at the mesenterium of the descending sigmoid colon. These dilated veins were connected between the IMV and the left renal vein. A diagnosis of Retzius shunt was made, and laparoscopic low anterior resection with lymph node dissection was performed. A pathological examination of the colonic mesenterium revealed AVM communicating with the dilated IMV and Retzius shunt. The preoperative evaluation of aberrant vessels by three-dimensional CT is particularly useful for patients with vascular malformations to ensure safe laparoscopic surgery.

A Rare Cause of Abdominal Pain: IgG4-Related Sclerosing Mesenteritis.

A 67-year-old man with previous cardiovascular disease was referred to our consultation due to a 5-month history of recurrent epigastric pain. Esophagogastroduodenoscopy and full blood workup presented no alterations. CT scan showed an irregularly shaped mass at the root of the mesentery, measuring 40x25x47mm, with spiculated contours and retractile behaviour (a). Simultaneous densification of the adjacent fat and infracentimetric ganglionic formations scattered throughout the mesentery were shown. Surgical biopsy revealed extensive storiform fibrosclerosis, with the presence of interstitial lymphoplasmocytic infiltrate and obliterative phlebitis (b); the plasma cells had mostly IgG expression, with IgG4:IgG ratio >40% (c), accounting for more than 30- 40 IgG4 plasma cells per field. The serum IgG4 level was 137mg/dL. A diagnosis of IgG4-related sclerosing mesenteritis was made, without other organ involvement. Prednisolone (0.6mg/kg/d) improved partially the abdominal pain, so steroid sparing strategy with off-label rituximab was associated. Due to its low prevalence, the understanding of this entity is scarce, and its diagnosis is challenging. Unlike other manifestations of IgG4-related disease, the intra-abdominal disease is identified in later stages, due to unspecific symptoms. This case aims to raise awareness about this condition as a differential diagnosis of abdominal pain.

A Case of Cushing's Syndrome from Well-Differentiated Neuroendocrine Tumors of the Small Bowel and Its Mesentery.

Adrenocorticotropic (ACTH)-producing neuroendocrine tumours (NETs) are rarely found in the small bowel, and primary mesenteric NETs have only been reported in a few cases globally. We report the case of a 68-year-old female with ectopic Cushing's syndrome due to excessive ACTH secretion from small bowel primary lesions and mesenteric metastasis. Initially, only the mesenteric mass was detected on imaging and endoscopy/colonoscopy, and it was only with surgical exploration that the small bowel lesions were found. This highlights the importance of high clinical suspicion and robust investigation when locating NETs. Surgical resection of the affected small bowel and mesentery was the definitive treatment for this patient. Initial hydrocortisone replacement therapy was needed, and subsequent biochemical tests and clinical reviews demonstrated no recurrence.

Mesenteric lipoblastomatosis: an uncommon fat-containing childhood tumour diagnosed on imaging.

Lipoblastomatosis of mesentery is an extremely rare benign fat-containing mesenchymal tumour in infants and young children. On imaging, it appears as a solid infiltrating mass interspersed with macroscopic fat. We describe the distinctive imaging features of a large mesenteric Lipoblastomatosis, corroborated with intraoperative and histopathological features. We hope the case report and short review about this rare entity will increase the diagnostic confidence of reading radiologists while formulating differentials for lesions of similar appearance in the paediatric age group.