Laparoscopic-Assisted Resection for an Extra-gastrointestinal Stromal Tumor Arising From the Mesentery of the Small Intestine: A Case Report.

Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors that arise in the muscular or submucosal layers of the gastrointestinal tract. Extra-gastrointestinal stromal tumors (EGISTs) are rare primary entities that develop outside the digestive tract which are histologically and immunologically similar to GISTs. We present the case of a 52-year-old female diagnosed with a primary EGIST arising in the small bowel mesentery four months after undergoing hormone therapy for multiple uterine myomas. Transvaginal ultrasonography and MRI revealed a pelvic mass suspected to be a GIST. The patient was treated with laparoscopic-assisted partial resection of the small bowel. Histopathological examination of the surgical specimen confirmed the diagnosis of an EGIST. Imatinib treatment was initiated, and no clinical evidence of recurrence or metastasis was detected postoperatively. Because EGISTs are extremely rare, the differences between EGISTs and GISTs, the degree of malignancy, and prognosis have not been fully investigated. Further studies are needed to accumulate additional cases. The present case shows that laparoscopic-assisted excision can be successfully used to manage EGISTs.

A rare clinical case of extra-gastrointestinal stromal pancreatic tumor.

Extra-gastrointestinal stromal tumors arising from the pancreas are extremely rare. To date, just over 30 cases have been described in the world literature. A clinical observation of a 67-year-old patient with dull epigastric pain and a large cystic solid neoplasm instrumentally identified as an extra-gastrointestinal stromal tumor of the head of the pancreas is presented. The volume of surgical intervention consisted of pancreatogastroduodenectomy and right-sided hemicolectomy, since tumor invasion into the transverse mesocolon was detected intraoperatively. The final diagnosis of extra-gastrointestinal stromal sarcoma of the head of the pancreas with invasion into the mesocolon pT4N0M0, stage IIIb was made on the basis of histopathology and immunohistochemistry results.

Acute Pyelonephritis and an Incidental Diagnosis.

Gastrointestinal stromal tumors (GISTs) arise from the gastrointestinal tract. In rare cases, extra-gastrointestinal stromal tumors (EGISTs) occur in the omentum, mesentery, et cetera. They are mostly asymptomatic or have unspecific symptoms. Risk stratification classification systems are based on tumor size, mitotic rate, location, and perforation. The gold standard for diagnosis is a computed tomography (CT) scan. Ultrasound/CT-guided percutaneous biopsy allows histopathology and immunochemistry results (most stain positive for CD117 (c-KIT), CD34, and/or DOG1). Mutational analysis (most are in proto-oncogene c-KIT and platelet-derived growth factor receptor A (PDGFRA)) determines appropriate therapy. Surgical resection is the gold standard of treatment, with adjuvant and neoadjuvant molecular-targeted therapies depending on recurrence risk and mutations. This report describes a rare case of GIST (omentum EGIST) with a rare presentation (acute pyelonephritis) in a 67-year-old woman. Abdominal examination showed tenderness and a positive Murphy sign on the left side. Blood analysis presented microcytic hypochromic anemia, aggravated renal function, leukocytosis, and increased C-reactive protein. Abdominal CT revealed a heterogeneous abdominal mass, and a CT-guided biopsy showed epithelioid cells positive for CD117 and DOG1, which is compatible with a GIST. The patient underwent surgery that determined the GIST's origin from the greater omentum. Histology revealed an epithelioid GIST with large dimensions and a high histologic grade. Genetic testing detected a variant in the PDGFRA gene. With a high risk of progression, the patient received a three-year course of imatinib.

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.

Primary Hepatic Extra-gastrointestinal Stromal Tumors: Molecular Pathogenesis, Immunohistopathology, and Treatment.

Gastrointestinal stromal tumors are the most common mesenchymal tumors of the gastrointestinal tract. They originate from the interstitial cells of Cajal and are usually found in extrahepatic gastrointestinal sites. However, a small subset are derived from the liver and are known as primary hepatic gastrointestinal stromal tumors (PHGIST). They have a poor prognosis and are historically difficult to diagnose. Our objective was to review and update the latest evidence-based knowledge concerning PHGIST, with a focus on epidemiology, etiology, pathophysiology, clinical presentation, histopathology, and treatment. These tumors are usually found incidentally, occur sporadically, and are associated with mutations of KIT and PDGFRA genes. PHGIST is a diagnosis of exclusion, as it has the same molecular, immunochemistry and histological appearance as gastrointestinal stromal tumors (GIST). Thus, imaging, such as positron emission tomography-computed tomography (PET-CT) must be used to rule out metastatic GIST before a diagnosis can be made. However, with mutation analysis and pharmacological advances, tyrosine kinase inhibitors are typically pursued with or without surgical intervention. Other potential treatments include transcatheter arterial chemoembolization and tumor ablation. However, these are typically considered palliative options. As there are only a limited number of publications regarding PHGIST, data concerning morbidity and mortality are not yet available. Immunohistopathology can help develop screening guidelines and evaluating resistance to treatment.

Retroperitoneal extra gastrointestinal stromal tumor: A case report.

INTRODUCTION: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors. Researchers do not know precisely what leads to GISTs, but genetic mutations play an important role. These mutations have no apparent cause. GISTs are usually asymptomatic tumors, although GI bleeding and weight loss can occur. CT is preferred for investigating potential GISTs. CASE PRESENTATION: A 36-year-old unmarried Syrian female came to the hospital complaining of recurrent abdominal pain. CT revealed a large mass occupying a significant portion of the left hypochondrium and the lower part of the epigastrium. The tumor exceeded the median line to the right, pressing on the mesenteric vessels and the intestinal loops below. Immunohistochemistry results showed moderate positivity to CD117 and CD34, which were compatible with the diagnosis of GIST. The entire mass was excised. Physicians performed CT follow-ups every three months for 18 months, and no evidence of recurrence was observed. DISCUSSION: Extragastrointestinal GISTs are a rare subtype of GISTs that occur outside the GI tract. GISTs previously used to be misdiagnosed as leiomyoma, leiomyosarcoma, leiomyoblastoma, and schwannoma. Treatment depends on surgery with adjuvant therapy tyrosine kinase inhibitors. Follow-up is recommended as the risk of recurrence is high. CONCLUSION: We recommend that GIST, as an extremely rare tumor, should be considered in the differential diagnoses of masses that occur in the extra-intestinal region. Usually, patients need surgery with lymph node resection. However, this was not needed in our case.

Extra-gastrointestinal stromal tumor of the pancreas: A case report.

INTRODUCTION: Gastrointestinal stromal tumors (GIST) represent the most common mesenchymal tumors of the gastrointestinal tract. In rare cases, these tumors do not develop in the gastrointestinal tract and are defined as extra-gastro-intestinal stromal tumors (EGISTs). Pancreatic EGIST is extremely rare. We reported a case of EGIST of the pancreas in a 53-year-old patient. PRESENTATION OF CASE: A 53-year-old man presented with chronic epigastralgia. An enhanced CT scan showed a solido-cystic tumor of the pancreatic body-tail. The patient underwent a laparotomy. Cytology fine needle aspiration did not find any tumor cells. Enucleation was performed. Histopathology and immunohistochemical examination confirmed the diagnosis of EGIST (CD117 +, Dog-1 +) with a high risk of malignancy. The patient received adjuvant therapy. There was no evidence of disease recurrence after 8 months of follow-up. CLINICAL DISCUSSION: We reported a rare case of a pancreatic EGIST. Enucleation was performed permitting to avoid distal pancreatectomy and thus decreasing morbidity rates. The clinical presentation is not specific and it depends on the location and the size of the tumor. CT scan shows hypervascular tumors with no regional lymph nodes metastasis but is not accurate in assessing diagnosis. Whenever possible, enucleation should be performed. This tumor should be considered in the differential diagnoses of pancreatic neoplasms. CONCLUSION: Pancreatic stromal tumor is extremely rare. There are no specific clinical and radiologic findings. A careful decision should be made after a discussion in a multidisciplinary coordination meeting. Surgical resection is the cornerstone of the treatment. Whenever possible, enucleation is sufficient.

KIT (CD117) Positive Huge Primary Malignant Extra Gastrointestinal Stromal Tumors (EGISTs) Arising From Jejunal Mesentery: A Rare Case Report.

Tumors arising outside gastrointestinal systems are known as extra gastrointestinal stromal tumors (EGISTs). Outside gastrointestinal sites include the mesentery, omentum, peritoneum, pancreas, and liver. Our case highlights a rare occurrence of an EGIST in jejunal mesentery in a 45-year-old male with an asymptomatic large abdominal growth and weight loss. A contrast-enhanced multi-dimensional computed tomography scan showed a large heterogeneous mass in the left hypochondrium. lumbar, and paraumbilical regions. Later, the patient underwent surgical resection of the tumor along with the involved jejunal segment and small tumor masses in the mesentery. Histopathological examination reported a malignant EGIST of mesentery and invasion into the jejunum, further confirmed by immunohistochemistry (IHC) markers like CD117 and smooth muscle actin with a high proliferative index (Ki67). One should be aware that these are different from other malignancies arising from the mesentery. Their cell of origin is different and needs a specific type of treatment. The clinical history, radiological findings, histopathology, and IHC help in diagnosing especially when they are arising from unusual areas like jejunal mesentery. Surgical intervention and chemotherapy are mainstay treatments.

Primary extra gastrointestinal stromal tumors of the abdomen.

OBJECTIVE: In the present study, we aimed to evaluate the clinicopathological features and prognostic factors in extra-gastrointestinal stromal tumor (EGIST) cases, which are observed very rare, by examining the data the cases obtained in a single center. METHODS: Data of 14 EGIST cases who were operated by a general surgeon between January 2007 and May 2020 were obtained and analyzed. RESULTS: The median age was 47.5 (range: 34-87) years. A total of 135 patients were operated for GIST, and 14 (10.4%) of these patients were EGIST. The mean tumor diameter was 16.8±10.5 (range: 2.8-40) cm. The mitotic index was 5/50 high power field and below in seven (50%) cases. Twelve (85.7%) of the patients were in the high-risk group. The overall survival (OS) rate was 80%, and the 5-year survival rate was 88.9%. Mean OS was 78.5±50.7 months, 5-year OS and disease-free survival (DFS) were both 53.3±20.0 months, and overall DFS was 58.0±59.8 months. The mean OS and DFS durations were found to be significantly lower in women than men (p=0.006 for both comparisons). The mean OS was found to be significantly lower in patients over 60 years of age compared to those aged 60 and under (p=0.013). CONCLUSION: In the present study, it has been determined that the rare EGISTs are large in size and that the mitotic index is often low. In addition, it has been observed that the prognosis may be similar to other GISTs, however, may be worse in elderly patients and in women.

Whole-exome sequencing for high-risk primary prostatic extra-gastrointestinal stromal tumor: A case report.

The low incidence rates of prostatic extra-gastrointestinal stromal tumors (EGIST), combined with the lack of published guidelines on its treatment, often results in its misdiagnosis and challenges in the treatment of patients, even in cases with high-risk factors. The present case study reported a 65-years-old Chinese male patient, who presented with intermittent hematuria and lower urinary tract symptoms for three months. The colonoscopy results revealed no gastrointestinal lesions; however, a core biopsy diagnosed an EGIST, which subsequently underwent radical prostatocystotomy, standard pelvic lymph node resection, and bricker ileal conduit diversion. The postoperative pathological results suggested a high-risk primary prostatic EGIST, according to the aggressive behavior of the GIST. The immunohistochemistry results revealed the positive expression of CD117, DOG1, CD34, androgen receptor AR, prostate-specific antigen (PSA), a 2% Ki-67 index and a positive surgical margin. The whole exome sequencing (WES) results revealed that the patient harbored a single nucleotide mutation in 121 genes and copy number variations in 601 genes, including a defect in c-Kit (in-frame deletion in p.Q556-V560; fold, 17.5%). By compiling the data obtained from the ConsensusPathDB and the drug-gene interaction databases and expert opinions, the patient was prescribed with the personalized drugs (400 mg per day imatinib mesylate and 50 mg per day bicalutamide, which were stopped when the PSA levels remained stable below 0.01 ng/ml) for 18 months follow-up and there were no signs of recurrence. In conclusion, WES identified multiple genomic alterations and the underlying genetic defect in the rare case enabled the evaluation of the prognosis and the decision of potential drug candidates. The underlying mechanism of the substantial genetic variations in the primary prostatic EGIST, as well as the malignant behaviors of the tumor, remain to be investigated.

A case of KIT negative extra-gastrointestinal stromal tumor arising in the greater omentum with predominant cystic formation.

We report a rare case of KIT-negative extra-gastrointestinal stromal tumor, in a 40-year-old woman. Contrast-enhanced computed tomography and magnetic resonance imaging revealed a >15-cm mass of multiple cystic lesions in the greater omentum. Histopathological findings after surgery showed a sheet-like growth of stellate tumor cells from epithelial cells, cystic degeneration, and mucus-like stroma. Immunohistochemistry was positive for discovered on GIST-1 (DOG1) but negative for CD117 (c-kit).

Current knowledge of primary prostatic extra-gastrointestinal stromal tumor: a case report and review of the literature.

The patient was a 62-year-old man diagnosed as having prostatic extra-gastrointestinal stromal tumor (EGIST) who was treated with imatinib. No recurrence or metastasis was found after a 6-month follow-up. We identified 14 cases of prostatic primary EGIST in PubMed and summarized these cases with our case. The patients' ages ranged from 31 to 78 years (average: 53.6 years), and most patients' prostate-specific antigen (PSA) concentrations were within normal limits (92.9%, 13/14). All patients underwent imaging examinations; prostatic masses measured 6 to 14.2 cm (mean: 9.43 cm), and imaging excluded secondary prostatic masses from the intestinal tract. By immunohistochemical staining, the tumors were positive for cluster of differentiation (CD)117 (71.4%, 10/14), DOG1 (100%, 7/7), and CD34 (100%, 14/14), and negative for smooth muscle actin (SMA) (71.4%, 10/14), desmin (100%, 11/11), and S100 (100%, 12/12). Treatment depended on the results of the gene mutation detection as well as the risk estimation according to tumor size and microscopic mitotic rates (>5 per 50 high-power fields: 60%, 6/10). Among the 12 patients with reported outcomes, nine achieved good results (no recurrence or metastasis), one achieved reduced mass volume, one experienced recurrence, and one died.

Giant hepatic extra-gastrointestinal stromal tumor treated with cytoreductive surgery and adjuvant systemic therapy: A case report and review of literature.

BACKGROUND: Primary extra-gastrointestinal stromal tumors (E-GIST) of the liver are rare. The clinical presentation may range from asymptomatic to bleeding or manifestations of mass effect. Oncologic surgery followed by adjuvant therapy with imatinib is the standard of care. However, under specific circumstances, a cytoreductive approach may represent a therapeutic option. We describe herein the case of an 84-year-old woman who presented with a tender, protruding epigastric mass. Abdominal computed tomography scan revealed a large, heterogeneous mass located across segments III, IV, V, and VIII of the liver. The initial approach was transarterial embolization of the tumor, which elicited no appreciable response. Considering the large size and central location of the tumor and the advanced age of the patient, non-anatomic complete resection was indicated. Due to substantial intraoperative bleeding and hemodynamic instability, only a near-complete resection could be achieved. Histopathology and immunohistochemical staining confirmed the diagnosis of primary E-GIST of the liver. Considering the risk/benefit ratio for therapeutic options, debulking surgery may represent a strategy to control pain and prolong survival. CASE SUMMARY: Here, we present a case report of a patient diagnosed with E-GIST primary of the liver, which was indicated a cytoreductive surgery and adjuvant therapy with imatinib. CONCLUSION: E-GIST primary of the liver is a rare conditional, the treatment is with systemic therapy and total resection surgery. However, a cytoreductive surgery will be necessary when a complete resection is no possible.

Primary extra-gastrointestinal stromal tumor (EGIST) of the mesentery: Case report and review of literature.

INTRODUCTION: Gastrointestinal stromal tumors (GISTs) represent <1% of all gastrointestinal (GI) tumors. Extra-gastrointestinal stromal tumors (EGISTs) are mesenchymal tissue neoplasm arising outside the GI tract. This rare group comprises only 5% of all GISTs. This case demonstrates a rare entity in a patient with non-specific symptoms, a large tumor size and unremarkable past personal and family history. PRESENTATION OF CASE: We present a 45-year old man with non-specific symptoms who was diagnosed with a primary EGIST arising in the small bowel mesentery after surgery. The tumor was not compromising the GI tract and it was completely resected. The tumor was sent for pathological examination that confirmed the diagnosis. Histological examination revealed a 15 cm in diameter mass, comprised of spindle cells and high mitotic activity. Treatment with imatinib mesylate was initiated. DISCUSSION: There have been only a few previous reports of EGISTs arising from the small bowel mesentery. It is believed that EGISTs originate from cells with similar pathological characteristics and biological behaviour as the intestinal cells of Cajal. Such tumors are associated with poorer prognosis, lager tumor size and younger presentation than their GI counterparts. The preferred treatment is complete surgical resection. The addition of specific tyrosine kinase inhibitors such as imatinib mesylate is recommended for high risk patients. Even though morphological and immunohistochemical similarities between GISTs and EGISTs are described, their pathogenesis, incidence, genetic background, complications and prognosis are not completely known because they are extremely rare. CONCLUSION: EGISTs are very rare tumors which originate from cells outside the GI tract and are associated with a more aggressive biological behavior than their GI counterparts. These tumors may grow without any clinical implications and should be kept in mind in the differential diagnosis for patients presenting with an abdominal mass. Further studies are needed due to lack of large patient cohort studies and long-term follow-up regarding the prognosis and management of this rare pathology.

Prevalence, diagnosis, and treatment of primary hepatic gastrointestinal stromal tumors.

Gastrointestinal stromal tumors (GIST), which is the most common mesenchymal tumor of the digestive tract, account for 1%-3% of gastrointestinal tumors. Primary stromal tumors outside the gastrointestinal tract are collectively referred to as extra GISTs, and stromal tumors in different regions often have different prognoses. A primary hepatic GIST is a rare tumor with an unknown origin, which may be related to interstitial Cajal-like cells. Although primary hepatic GIST has certain characteristics on imaging, it lacks specific symptoms and signs; thus, the final diagnosis depends on pathological and genetic evidence. This review summarizes all cases of primary hepatic GIST described in the literature and comprehensively analyzes the detailed clinical data of all patients. In terms of treatment, local resection alone or with adjuvant therapy was the prioritized choice to obtain better disease-free survival and longer survival time. For advanced unresectable cases, imatinib mesylate was applied as the first-line chemotherapy agent. Moreover, transcatheter arterial chemoembolization, radiofrequency ablation, and microwave ablation were shown to improve overall survival for selected patients. Liver transplantation was a final treatment option after resistance to chemotherapy developed.

Extra-gastrointestinal stromal tumor arising in the lesser omentum with a platelet-derived growth factor receptor alpha (PDGFRA) mutation: a case report and literature review.

BACKGROUND: Gastrointestinal stromal tumors (GIST) arising from sites other than the gastrointestinal (GI) tract, termed extra-gastrointestinal stromal tumors (EGIST), are rare. Among EGIST, those with platelet-derived growth factor receptor alpha (PDGFRA) mutations are even rarer, with only a few cases reported. About 80% of GIST has KIT mutations, and 10% of GIST have PDGFRA mutations, which commonly affect the TK2 domain (exon 18). Among the exon 18 mutations, the D842V substitution is limited to gastric GIST. In EGIST, the degree of KIT and PDGFRA mutations varies on where the location of the tumor is, and it is suggested that omental EGIST is similar to gastric GIST. Adjuvant imatinib therapy is recommended for high-risk GIST; however, it is known that imatinib is less effective against GIST with a PDGFRA D842V mutation. CASE PRESENTATION: A 75-year-old man was referred to our hospital with an extrinsic tumor of the lesser curvature of the gastric body. Intraoperative findings showed a tumor located outside of the lesser omentum with no connection between the tumor and the gastric wall. The tumor was subsequently resected. Pathological examination indicated a GIST arising in the lesser omentum measuring 70 mm in its longer dimension. Because the tumor had a PDGFRA mutation (D842V substitution), imatinib was suspected to lack efficacy to the tumor. Thus, although the tumor was considered clinically to have a high risk of recurrence, adjuvant imatinib therapy was not indicated. The patient has been free of recurrence for 29 months since the surgery. CONCLUSION: We described a case of EGIST with a PDGFRA mutation arising in the lesser omentum. And we reviewed 57 cases of omental EGIST and showed that the clinicopathological characteristics and mutation status in omental EGIST were very similar to gastric GIST. In particular, PDGFAR D842V mutation rate in omental EGIST seemed as high as that in gastric GIST. These results suggested that omental EGIST is strongly related to gastric GIST, so the behavior of omental EGIST might be akin to gastric GIST. However, further studies are required to determine the prognosis and the necessity of adjuvant therapy for EGIST with a PDGFRA mutation.

Primary Prostatic Extra-Gastrointestinal Stromal Tumor Treated with Imatinib Mesylate as Neoadjuvant and Adjuvant Therapy: A Case Report and Literature Review.

The current study presents a case of primary prostatic extra-gastrointestinal stromal tumor (EGIST) in a 43-year-old man who suffered acute urinary retention. The serum level of prostate-specific antigen was normal. Imaging examinations demonstrated a diffusely enlarged prostate compressing the rectum without evidence of metastasis. After excluding the possibility of secondary involvement by a rectal GIST, the pathologic diagnosis of primary prostatic EGIST was established based on microscopic study, immunohistochemistry, and molecular analysis. This patient is the first case with primary EGISTs of prostate received imatinib mesylate as neoadjuvant and adjuvant therapy reported in the literature to date. We hope this case could provide the experience of diagnosis and treatment of primary prostatic EGISTs.

Extra-Gastrointestinal Stromal Tumor Presenting as an Anterior Chest Wall Mass.

A 71-year-old man was referred for an anterior chest wall mass. Chest computed tomography (CT) and positron emission tomography-CT suggested a malignant tumor. Surgical biopsy through a vertical subxiphoid incision revealed an extra-gastrointestinal stromal tumor (EGIST). En bloc resection of the tumor, including partial resection of the sternum, costal cartilage, pericardium, diaphragm, and peritoneum, was performed. Pathologic evaluation revealed a negative resection margin and confirmed the tumor as an EGIST. On postoperative day 17, the patient was discharged without any complications. At the 2-week follow-up, the patient was doing well and was asymptomatic.

Extra-Gastrointestinal Stromal Tumor of Prostate.

BACKGROUND: Extra-gastrointestinal stromal tumor is defined as a mesenchymal neoplasm arising from soft tissues outside the gastrointestinal tract. Prostatic extra-gastrointestinal stromal tumor has rarely been noted. CASE REPORT: A 56 year-old man presented with pain in the anal region. A digital rectal examination revealed that the prostate was markedly enlarged with a smooth, bulging surface. Computerized tomography images showed a 6 cm heterogeneous, infiltrative tumor within the prostate gland extending to the trigon of the bladder, left seminal vesicle and rectum. The tru-cut biopsy of the prostate was reported as leiomyoma. It was decided to perform surgery and the masses were easily and completely removed from the adjacent structures. The case was reported as extra-gastrointestinal stromal tumor within the intermediate- risk category with free surgical margins. Four years after the surgery, a locoregional failure was observed and treated with imatinib. CONCLUSION: Stromal tumor, although rare, should be considered in the differential diagnosis in patients with an enlarged prostate.