Diagnosis Of Gastrointestinal Stromal Tumors Research Articles

Analysis of the efficacy of adjusting the dose of imatinib with therapeutic drug monitoring in adjuvant treatment after complete resection of gastrointestinal stromal tumors

Objective: To explore the efficacy of adjusting the dose of imatinib dose in the context of therapeutic drug monitoring (TDM) in patients with gastrointestinal stromal tumors (GISTs) who are receiving adjuvant therapy after complete resection of their tumors. Methods: This was a descriptive study. Inclusion criteria were (1) complete surgical resection with a pathological diagnosis of GIST, (2) postoperative adjuvant therapy with imatinib and dosage adjustment, (3) multiple TDM of imatinib, and (4) complete clinical, pathological, and follow-up data. The data of 70 patients with GISTs treated at Union Hospital, Tongji Medical College, Huazhong University of Science and Technology between January 2015 and December 2023 were collected retrospectively. The study cohort comprised 15 (21.4%) men and 55 (78.6%) women of median age 60 years (range: 25-82). Of the eligible patients, 49 (70.0%) were at high-risk, 14 (20.0%) at intermediate-risk, six (8.6%) at low-risk, and one (1.4%) at very low risk. Patients were followed up by the gastrointestinal stromal tumor clinic every 2-3 months and their plasma concentrations of imatinib were checked. The dose was adjusted to 300 mg/d or 200 mg/d depending on whether they had had ≥ grade III adverse reactions, and whether the first plasma concentration of imatinib was ≥ 1,500 μg/L or between the expected range of 760 μg/L-1,100 μg/L. Studied indicators included adverse reactions, quality of life before and after dose adjustment, and overall survival and recurrence-free survival (RFS) after dose adjustment. Results: Before dose adjustment, all 70 patients received 400 mg of imatinib daily, with initial TDM values of 1,900 ± 568 μg/L, for a median duration of 8.3 months. After dose adjustment, 60 patients received 300 mg daily, with a TDM of 1,216 ± 350 μg/L, whereas 10 received 200 mg daily, with a TDM of 1,023 ± 269 μg/L. The median duration of treatment after dose adjustment was 23.4 months. Compared with those whose dosages were not adjusted, the incidence of bone marrow suppression was significantly lower (74.3% [52/70] vs. 51.4% [36/70], χ2=9.202, P=0.010); as were the incidences of edema (95.7% [67/70] vs. 50.0% [35/70], χ2=40.526, P<0.001); skin reactions (70.0% [49/70] vs. 32.9% [23/70), χ2=22.495, P<0.001); and gastrointestinal reactions (38.6% [27/70] vs. 10.0% [7/70], χ2=15.899, P<0.001) in those whose dosages were adjusted. The average total scores for physical health before and after dose adjustment were 76 ± 5 and 88 ± 4, respectively; whereas the mental health scores were 75 ± 6 and 89 ± 4, respectively. The median follow-up period was 36 months (range 6-126). During the first 3 years of follow-up, five high-risk patients with non-gastric GISTs developed recurrences. The 3-year overall survival rate was 100%, and the 3-year RFS rate was 92.8%, high-risk patients having a 3-year RFS rate of 89.8%. Conclusion: The adverse reactions and quality of life of GIST patients with severe adverse reactions to adjuvant imatinib therapy after complete resection can be mitigated by appropriately reducing the dosage of imatinib under the guidance of TDM.

From following to surpassing: insight into GIST treatment development in China

Since the concept of GIST was proposed in 1983, the diagnosis and treatment of GIST in China have continuously progress. Over the two decades from 1990 to 2010, the diagnosis and treatment of GIST had achieved a foundation of development through the collective efforts of GIST scholars, from the first pathological review to the first expert consensus. The period from 2010 to 2020 marked rapid development. Besides the updates of expert consensus, other relevant expert consensus was published regarding pathology, surgery, targeted therapy, therapeutic drug monitoring, and patient' management. Based on the above development, China's first GIST guideline, the "CSCO Gastrointestinal Stromal Tumor Diagnosis and Treatment Guidelines (2020 Edition)", was published. This guideline considers regional development disparities, accessibility of treatments and diagnostic methods, and the social value of cancer care, maintaining its scientific rigor, fairness, and timeliness. Over the past 30 years, the diagnosis and treatment of GIST in China significantly development. However, we should recognize that further development must require more original Chinese research, which would better benefit the Chinese population.

Differential diagnosis of gastrointestinal stromal tumors versus leiomyomas by special stains

The objective of the study was to investigate whether special stains can differentiate gastrointestinal stromal tumors (GISTs) and gastrointestinal leiomyomas (GILs). In this retrospective study, 39 cases of GISTs (diameter, 0.2–8.8 cm) and 75 cases of GILs (diameter, 0.2–4.5 cm) were recruited, all biopsy specimens were obtained by endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR) excision, and the depth of excision included the whole mucosa, mucosal myometria, and most submucosa. GISTs and GILs were the most common types of mesenchymal tumors found anywhere along the gastrointestinal (GI) tract, from the esophagus to the rectum. GISTs were often associated with a higher risk of malignancy. In this study, the gender, age of onset, size and sites of the lesions, together with the number of mucosal or lamina propria lesions all have significant differences, nevertheless, there was no significant difference in cell morphology of GISTs and GILs tested by hematoxylin eosin (H&E) stain, and all showed low echo areas by EUS examination. In this retrospective study, the GISTs and GILs had been diagnosed by immunohistochemistry combined with clinical morphology. Subsequently, special stains including Masson’s trichrome (MT) stain, Alcian blue periodic acid-Schiff (AB-PAS) stain (pH 2.5), Wright-Giemsa (W-G) stain and periodic acid-Schiff (PAS) combined with diastase periodic acid-Schiff (D-PAS) stains were also applied in the diagnosis, the retrospective study results showed that 92.3% GISTs were stained blue with MT stain, 97.3% GILs were stained red with MT stain (P < 0.01), almost all GISTs were PAS-negative (light purple), in contrast, all GILs were PAS-positive (rose red) (P < 0.01), all of these experiments set control using the blood vessels stained by MT and AB-PAS stains. Nevertheless, there was no significant difference between GISTs and GILs stained by W-G stain. These obvious and meaningful differential results were also confirmed in the detection of new GISTs and GILs cases using MT and AB-PAS stains. In conclusion, MT and AB-PAS stains could also identify GISTs and GILs cases, particularly, AB-PAS was more sensitive and more specific, providing a more cost-effective, simple, and high sensitivity and specificity inspection methods, which should be noticed and widely used in the future, especially in resource-limited grass-roots testing institution or in cases with inconclusive immunostains or insufficient material.

Radiomics-based predictive model for preoperative risk classification of gastrointestinal stromal tumors using multiparametric magnetic resonance imaging: aretrospective study.

The aim of this study was to develop and assess aradiomics model utilizing multiparametric magnetic resonance imaging (MRI) for the prediction of preoperative risk assessment in gastrointestinal stromal tumors (GISTs). An analysis was performed retrospectively on agroup of 121 patients who received ahistological diagnosis of GIST. They were then divided into two sets, with85 in the training set and 36 in the validation set through random partitioning. Radiomics features from five MRI sequences, totaling 600 per patient, were extracted and subjected to feature selection utilizing arandom forest algorithm. The discriminatory efficacy of the models was evaluated through receiver operating characteristic (ROC) and precision-recall (P-R) curve analyses. Model calibration was assessed via calibration curves. Subgroup analysis was performed on GISTs with apathological maximum diameter equal to or less than 5 cm. Furtherly, Kaplan-Meier (K-M) curves and log-rank tests were used to compare the differences in survival status among different groups. Cox regression analysis was employed to identify independent prognostic factors and to construct aprognostic prediction model. The clinical model (ModelC) displayed limited predictive efficacy in the context of GIST. Conversely, aradiomics model (ModelR) incorporating five parameters exhibited robust discriminative capabilities across both the training and validation sets, yielding area under the ROC curve (AUC) values of 0.893 (95% confidence interval [CI]: 0.807-0.949) and 0.855 (95% CI: 0.732-0.978), respectively. The F1max scores derived from the P‑R curves were 0.741 and 0.842 for the training and validation sets, respectively. Noteworthy was the exclusion of the two-dimensional tumor diameter and tumor location when constructing ahybrid model (ModelCR) that amalgamated radiomics and clinical features. ModelR demonstrated asubstantially enhanced discriminative capacity in the training set compared with ModelC (p < 0.005). The net reclassification improvement (NRI) corroborated the superior performance of ModelR over ModelC, thereby enhancing diagnostic accuracy and clinical applicability. Patients in the high-risk group had significantly worse recurrence-free survival (RFS, p < 0.001) and overall survival (OS, p = 0.004), and the radiomics signature is an independent risk factor for RFS. The extended model incorporating the radiomics signature outperformed the baseline model in terms of risk assessment accuracy (p < 0.001). Our investigation underscores the value of integrating radiomics analysis in conjunction with machine learning algorithms for prognostic risk stratification in GIST, presenting promising implications for informing clinical decision-making processes as well as optimizing management strategies.

Appendiceal neurofibroma after resection of multiple gastrointestinal stromal tumors of the small intestine in a patient with neurofibromatosis type 1: a case report

BackgroundNeurofibromatosis type 1 (NF1), also known as von Recklinghausen disease, is an autosomal dominant disorder that can affect multiple organs. Although gastrointestinal manifestations, such as neurofibromas and gastrointestinal stromal tumors (GISTs), can occur, appendiceal neurofibromas are extremely rare, with no documented cases of their occurrence following other gastrointestinal lesions. Herein, we report a case of an appendiceal neurofibroma following the resection of multiple small intestinal GISTs.Case presentationA 68-year-old man with NF1 presented with melena and was diagnosed with anemia due to bleeding from multiple small intestinal GISTs. Laparoscopic three partial resection of the small intestine was performed to control the bleeding. Histopathologic examination revealed the proliferation of spindle cells that are positive for c-kit and Discovered on GIST-1, confirming the diagnosis of GIST. Two years later, a follow-up computed tomography (CT) scan revealed a progressively enlarging mass in the appendix with suspected invasion into the small intestine. Positron emission tomography/CT showed fludeoxyglucose accumulation in the tumor. Therefore, considering the possibility of malignancy, laparoscopic ileocecal resection with lymph node dissection was performed. Postoperatively, melena was observed, but the anemia did not progress and improved with fasting and hemostatic therapy. The patient was eventually discharged on postoperative day 8. Histopathologic examination revealed spindle cell proliferation with positivity for S-100, confirming the diagnosis of neurofibroma.ConclusionsPatients with NF1 can develop a variety of gastrointestinal lesions. Appendiceal neurofibroma can be difficult to diagnose preoperatively and differentiate from malignancy. Hence, surgical resection should be considered.

Gastrointestinal Stromal Tumor (GIST) masquerading as undifferentiated gastric carcinoma; a potential diagnostic pitfall

Abstract Introduction/Objective Epithelioid variant of the GIST can mimic carcinoma and misdiagnosis has grave implications in patient management. The purpose of this report is to describe such a case and to remind pathologists to keep epithelioid GIST in the differential. Methods/Case Report A 66-year-old male presented with melena for 2 weeks. Endoscopy showed a large, infiltrative, and ulcerated mass in the gastric fundus. CT imaging showed a 16 x 12 cm mass-like gastric wall thickening, most compatible with gastric carcinoma. The mass was biopsied, which showed sheets and clusters of anaplastic, large to medium sized polygonal epithelioid cells with areas of rhabdoid phenotype characteristic of an undifferentiated gastric carcinoma. Initial immunohistochemical stains including pancytokeratin and p40 showed negativity, prompting additional stains including Cam5.2, SOX10, CD45, synaptophysin, INSM1, EMA, CK7 and CK20- all of which were also negative. At this point the main diagnostic consideration was undifferentiated gastric carcinoma. However, for completion purposes, DOG1 stain was added that came back positive. Since rhabdoid morphology is a bit unusual, even for epithelioid GISTs, and literature review suggested that DOG1 positivity can be seen in up to 11% of carcinomas, confirmatory NGS testing was performed. This demonstrated a KIT W557R gene mutation, confirming the diagnosis of GIST. The patient was treated with imatinib and subsequent imaging showed decreased size and hypermetabolism of the gastric mass. Patient is alive with disease 6 months after the diagnosis. Results (if a Case Study enter NA) NA Conclusion Using a panel of appropriate immunohistochemical stains and keeping epithelioid GIST in the differential can help avoid this diagnostic pitfall.

The Role of MSCT in Evaluating Tumor Size, Density, Immunohistochemical Classification, and Pathological Risk in GIST Patients

Objective: To investigate the role of multilayer spiral CT (MSCT) in evaluating patients with gastrointestinal stromal tumors (GIST), particularly its utility in determining tumor size, immunohistochemical classification, and pathological risk. Methods: A retrospective analysis was conducted on 22 GIST patients, confirmed by surgical pathology between January 2019 and December 2023. All patients underwent MSCT examination prior to surgery. Tumor size, density, and immunohistochemical classification from the MSCT results were compared with the postoperative pathological findings. Additionally, the ability of MSCT to predict GIST risk grade was evaluated in combination with immunohistochemical analysis results. Results: No significant differences were found between the preoperative MSCT findings and postoperative pathological results in terms of tumor size, density, or immunohistochemical classification in GIST patients. MSCT also enhanced the ability to predict GIST risk grades. Conclusion: MSCT demonstrates significant clinical value in the diagnosis and risk assessment of GIST, aiding in the prediction of the tumor’s biological behavior and patients’ treatment responses.

SP9.8 - Assessing the quality of guidelines for the management of Gastro-Intestinal Stromal Tumour

Abstract Introduction Gastro Intestinal Stromal Tumours (GISTs) are tumours of the gastro-intestinal tract that arise from connective tissue and they have potential for malignancy. A number of guidelines exist in their management. The aim of this study is to assess the quality of these guidelines. Methods A search of the literature was undertaken for appropriate guidelines pertaining to the diagnosis and management of GISTs. The AGREE II checklist was used to assess the current GIST guidelines. Results A total of nine guidelines were included in this study. The overall median score across all guidelines was 68% (lowest; 50%, highest 89%). Guidelines tended to score highly in Domain IV (Clarity of Presentation, median score 76%) as well as Domain VI (Editorial Independence, 67%) and Domain I (Scope and Purpose, 61%). However, lower scores were noted in the Domain V (Applicability, 39%), Domain III (Rigor of Development, 52%) and Domain II (Stakeholder Involvement, 56%). None of the guidelines scored a unanimous ‘Yes’ vote for clinical usage, and all needed some level of modifying. Conclusion Whilst some of the current guidelines for the management of GISTs is of a high quality, there is a need for improvement with regards to the quality of the methodology used to formulate the guidelines and how they can be implemented in daily clinical use.

Gastrointestinal Stromal Tumors: Variants and Some Pitfalls That They Create

The diagnosis of gastrointestinal stromal tumors (GISTs) is generally straightforward using a combination of histologic evaluation and pertinent immunohistochemical staining with CD117/kit and DOG-1 (discovered on GIST) antibodies. However, this tumor can be challenging in cases with an unusual morphology, in limited biopsies, for those in uncommon sites, post-treatment, and when other neoplasms express CD117/kit and DOG-1, thereby mimicking GIST. Finding epithelioid GISTs in the stomach in younger patients should prompt testing for succinate dehydrogenase (SHD)-deficiency using immunohistochemical staining for subunit B (SDHB). However, SDH-deficient GISTs can also arise in older patients, or as part of the Carney triad or Carney-Stratakis syndrome. GISTs with PDGFRA mutations can also prove difficult if they lack kit expression. It is also important to consider morphologic and immunophenotypic changes associated with treatment, including the potential absence of kit expression, particularly in GISTs that have metastasized. Therefore, obtaining clinical information regarding prior therapy with a tyrosine kinase inhibitor (TKI) is crucial.

Hypercalcaemia in gastrointestinal stromal tumour and sarcoidosis: a case report

BackgroundHypercalcaemia is a common manifestation of sarcoidosis but is sparingly described in gastrointestinal stromal tumours (GISTs). We describe a case of acute kidney injury and hypercalcemia resulting from simultaneous diagnosis of GIST and sarcoidosis, the presentation of which has not yet been reported.Case PresentationA 61-year-old male presented with acute kidney injury and hypercalcemia, with elevated 1,25-dihydroxyvitamin D levels. Investigations demonstrated a large gastric antral mass which was resected and proven to be GIST. Histopathology of incidentally found liver nodules revealed non-necrotising epithelioid granulomas consistent with concomitant sarcoidosis. The hypercalcemia was successfully treated with bisphosphonate therapy, resection of the GIST and a four month course of corticosteroids, which was truncated due to a mycobacterial infection.ConclusionsOur case report is the first to describe hypercalcemia due to GIST and biopsy-proven sarcoidosis, thereby raising the possibility of a common pathophysiological pathway relating the two entities. We review the literature describing the mechanisms of hypercalcaemia in GIST and the association between GIST and sarcoidosis.

A primary leiomyosarcoma of small intestine: A rare case report

Primary leiomyosarcoma of small intestine originating from smooth muscle cell is extremely rare entity. It mimics gastrointestinal stromal tumor (GIST) because of their common morphological appearance. Microscopic and immunochemistry findings are necessary to differentiate Leiomyosarcoma from gastrointestinal tumor (GIST). We report a case of 58-year-old male patient presented to tertiary care hospital with complain of generalized abdominal pain, vomiting, early satiety and constipation. Physical examination revealed no significant findings. Imaging findings showed Ileo-Ileal intussusceptions. Neither CT scan nor MRI reveal any evidence of tumor. The patient underwent exploratory laparotomy which revealed polypoidal mass in ileum. Resection and anastomosis of distal Ileum done &amp; specimen received in histopathology department. On microscopic examination, Diagnosis of GIST &amp; Leiomyosarcoma was considered. Immunohistochemistry was positive for Desmin marker and negative for CD 117, DOG 1, S-100 &amp; ALK marker. The diagnosis of High grade Leiomyosarcoma was confirmed.

Radiomics in the differential diagnosis of gastrointestinal stromal tumors and leiomyomas. A literature review

Radiomics in the differential diagnosis of gastrointestinal stromal tumors and leiomyomas. A literature review

Neoadjuvant Imatinib in Gastrointestinal Stromal Tumors (GIST): The First Analysis of a Mexican Population.

Introduction Gastrointestinal stromal tumors (GISTs) are neoplasms originating from the interstitial cells of Cajal, pacemaker cells responsible for intestinal motility. Patients with locally advanced GISTs and those with borderline resections due to the proximity of vital anatomical structures, which could result in unacceptable post-surgical morbidity, require special therapeutic consideration. Imatinib, a tyrosine kinase inhibitor, has demonstrated significant successin the non-surgical management of metastatic GIST, and its favorable impact on overall survival in the adjuvant setting makes it logical to speculate on the benefit it could provide as a neoadjuvant medication in patients with locally advanced disease. Methods Patients aged 18-90 years with a diagnosis of GIST confirmed by immunohistochemistry (CD117 positivity) who were treated at the Oncology Hospital of Centro Médico Nacional Siglo XXI in Mexico City from January 2012 to December 2016 were included in the study. It is a retrospective study with a duration of four years. Clinical data were collected from the medical records, which included sex, age, tumor location, initial resectability, reason for unresectability, initial tumor size, and mitotic rate. In the case of unresectable disease, patients who were evaluated by medical oncology and who had received treatment with 400 mg of imatinib daily were evaluated. Results A total of 312 patients diagnosed with GIST were analyzed. One hundred thirty-one were men (42%) with a mean age of 57 years, and 181 were women (58%) with a mean age of 59 years. The most frequent anatomical location was the stomach (n=185, 59.2%). At the time of diagnosis, 210 patients (67.3%) presented with resectable disease, while n=102 patients (32.7%) had unresectable disease. A total of 102 patients with unresectable disease received therapy with 400 mg of imatinib per day. Sixteen patients (15.7%) presented a reduction in tumor dimensions and underwent surgery. Conclusion The study highlights the importance of complete surgical resection and the potential benefit of neoadjuvant imatinib therapy in converting unresectable to resectable disease. The results suggest that imatinib can be effective in converting unresectable GISTs to resectable ones, allowing for a complete resection to be performed and obtaining an R0 resection in 93.7% of these cases.

Gastro Intestinal Stromal Tumor: Cases Series Report

Gastrointestinal stromal tumors (GISTs) are rare mesenchymal tumors of the alimentary tract. Now a day GISTs represents 0.1-3% of all gastrointestinal malignancies, making it a diagnostic challenge. Lesions are frequently located in stomach and proximal small intestine but rarely elsewhere in the abdomen. They are believed to result from mutations of protooncogenes c-Kit or platelet-derived growth factor receptor alpha polypeptide, this increase tyrosine kinase receptor activity, leading to uncontrolled proliferation of stem cells that differentiate into cells of Cajal. They can occur at any age but predominantly in middle-aged people and in elderly. We reported the cases presented to our hospital with progressively distension of the abdomen, finding in diagnostic image suggested GIST without evidence of metastasis disease, total excision was done, Cytologic and immunohistochemistry analysis confirm diagnosis of GISTs.

A Rare Case Of Early Gastrointestinal Stromal Tumor In 34-Year-Old Woman: A Caution For Adnexal Tumor Mimicry

Introduction: Gastrointestinal Stromal Tumors (GISTs) are the leading type of mesenchymal tumor in the gastrointestinal (GI) tract, constituting 80% of these tumors and 0.1% to 3% of all gastrointestinal malignancies. They arise from spindle-shaped mesenchymal cells known as interstitial cells of Cajal. Its onset can be at any age, with the peak occurring in the sixth decade. Case Presentation: We report the case of a 34-year-old woman with a complaint about a lump in her lower abdomen that has been progressively enlarging over the past year without any significant symptoms following the lump. Findings in the ultrasound suggest an ovarian mass. Laparotomy was carried out, and while no ovarian mass was found, instead a mass was identified in the mesentery of the small bowel. As a result, a complete excision of the tumor was performed, with histopathologic and immunohistochemical results confirming a GIST diagnosis. Conclusion: Representing a tiny percentage of gastrointestinal tumors, GISTs are rare. GISTs may be asymptomatic or present without any typical symptoms. Sole reliance on clinical and radiological investigations can cause them to be easily overlooked. Awareness of GIST is critical and care must be taken in diagnosis since other tumor can mimic GISTs in endoscopic, imaging, and histological findings.

Use of Endoscopic Ultrasound Elastography to Differentiate between Gastrointestinal Stromal Tumor and Leiomyoma Localized in the Upper Gastrointestinal Tract.

Gastrointestinal stromal tumors (GISTs) have malignant potential. Distinction of GISTs from leiomyoma is important to the decision of follow-up or treatment for upper gastrointestinal tract subepithelial lesions (SELs). There are few studies on the evaluation of gastrointestinal SELs with endoscopic ultrasound (EUS) elastography. To evaluate the efficiency of strain ratio (SR) measurement and Giovannini's classification (Gc) by EUS elastography in differentiating GISTs from leiomyomas. Twenty-three lesions with histopathological diagnoses of 13 GISTs and 10 leiomyomas were evaluated. The lesions' SR values were obtained from EUS reports retrospectively. Giovannini's classification was performed according to the elastography images recorded in the system. The effectiveness of SR and Gc in the distinction between GIST and leiomyomas was evaluated. Twelve of the GISTs and 3 of the leiomyomas were with scores 4 and 5 according to Gc (p = 0.006). Gastrointestinal stromal tumors had a higher SR than leiomyomas (p = 0.001). For the diagnosis of GISTs, sensitivity/specificity/diagnostic accuracy were 92.3%/80%/87% for SR alone, 92.3%/70%/82.6% for Gc alone, and 84.6%/80%/82.6% for the use of both SR and Gc. This is the first study in which semi-quantitative (SR) and qualitative (Gc) methods were evaluated together for the distinction of GISTs and leiomyomas. The sensitivity of SR alone for diagnosing GIST is higher than that of Gc alone or the combination of both methods. Although SR alone does not diagnose GIST, it can be used as an auxiliary method in biopsy and follow-up decisions. Erdem RE, Bektaş M, Ellik ZM, et al. Use of Endoscopic Ultrasound Elastography to Differentiate between Gastrointestinal Stromal Tumor and Leiomyoma Localized in the Upper Gastrointestinal Tract. Euroasian J Hepato-Gastroenterol 2024;14(1):20-23.

Primary retroperitoneal paraganglioma mimicking gastric GIST: Case report

Introduction: A paraganglioma is a tumor originating from the sympathetic or parasympathetic nervous system. Its diagnosis is sometimes difficult, especially if it occurs in an atypical location. We report the case of a patient who presented with a diagnosis of gastric GIST and underwent surgical resection and whose postoperative histopathological examination revealed that it was a paraganglioma. Case report: A 38-year-old female patient who underwent cesarean section one year ago, had isolated epigastralgia for two years, the clinical examination was without abnormalities, and the patient benefited from an oesogastroduodenal fibroscopy showing an extrinsic compression aspect at the level of the greater curvature, the abdominal CT scan showed an 8 cm intraperitoneal mass in contact with the lesser gastric curvature evoking a gastrointestinal stromal tumor aspect. The biological work-up was without abnormalities. Surgery was performed to remove the retroperitoneal mass and a final diagnosis of paraganglioma was made, eliminating the initial diagnosis of gastrointestinal stromal tumor. Discussion: There are lessons to be learned from our case first, paraganglioma can be misdiagnosed. Second, misdiagnosis can be misled by clinical diagnosis and imaging. Third, misdiagnosis can lead to high morbidities and mortality. Conclusion: The correct knowledge of this pathology, including the differential diagnosis, is fundamental to establishing the correct diagnosis. In addition, close follow-up of these cases should be considered because of the high risk of metastatic disease.

Utility of EUS-Guided FNAC in the Diagnosis of Spindle Cell Lesion of the GI Tract: A Case Report

ABSTRACT Gastrointestinal (GI) tumors pose a diagnostic challenge due to their diverse histology and location. EUS was first used clinically in 1980. Since its inception, it has emerged as a valuable diagnostic tool for GI lesions, to a versatile therapeutic modality, encompassing a wide range of indications. EUS faces challenges in distinguishing benign from malignant lesions. The partnership between cytopathologists and endoscopists, coupled with rapid on-site evaluation (ROSE), has become crucial in patient management. Recent technical advancements along with the addition of FNAC have greatly increased its diagnostic accuracy. Endoscopic ultrasonography-guided fine-needle aspiration cytology (EUS-FNAC) has become a routine practice in many healthcare facilities, aiding in the diagnosis of mediastinal, GI, and pancreatic malignancies. EUS-FNAC offers several advantages, such as multi-site aspiration and lower cost as compared to other procedures. Even its potential in the area of molecular studies has been recently investigated. In this case study, a 45-year-old man who underwent EUS-FNAC is presented. The combination of histology, immunohistochemistry, and EUS-FNAC allowed us to make a conclusive diagnosis of GI stromal tumors (GIST).

Utility of Clinical Next Generation Sequencing Tests in KIT/PDGFRA/SDH Wild-Type Gastrointestinal Stromal Tumors.

Objective: The vast majority of gastrointestinal stromal tumors (GISTs) are driven by activating mutations in KIT, PDGFRA, or components of the succinate dehydrogenase (SDH) complex (SDHA, SDHB, SDHC, and SDHD genes). A small fraction of GISTs lack alterations in KIT, PDGFRA, and SDH. We aimed to further characterize the clinical and genomic characteristics of these so-called "triple-negative" GISTs. Methods: We extracted clinical and genomic data from patients seen at MD Anderson Cancer Center with a diagnosis of GIST and available clinical next generation sequencing data to identify "triple-negative" patients. Results: Of the 20 patients identified, 11 (55.0%) had gastric, 8 (40.0%) had small intestinal, and 1 (5.0%) had rectal primary sites. In total, 18 patients (90.0%) eventually developed recurrent or metastatic disease, and 8 of these presented with de novo metastatic disease. For the 13 patients with evaluable response to imatinib (e.g., neoadjuvant treatment or for recurrent/metastatic disease), the median PFS with imatinib was 4.4 months (range 0.5-191.8 months). Outcomes varied widely, as some patients rapidly developed progressive disease while others had more indolent disease. Regarding potential genomic drivers, four patients were found to have alterations in the RAS/RAF/MAPK pathway: two with a BRAF V600E mutation and two with NF1 loss-of-function (LOF) mutations (one deletion and one splice site mutation). In addition, we identified two with TP53 LOF mutations, one with NTRK3 fusion (ETV6-NTRK3), one with PTEN deletion, one with FGFR1 gain-of-function (GOF) mutation (K654E), one with CHEK2 LOF mutation (T367fs*), one with Aurora kinase A fusion (AURKA-CSTF1), and one with FANCA deletion. Patients had better responses with molecularly targeted therapies than with imatinib. Conclusions: Triple-negative GISTs comprise a diverse cohort with different driver mutations. Compared to KIT/PDGFRA-mutant GIST, limited benefit was observed with imatinib in triple-negative GIST. In depth molecular profiling can be helpful in identifying driver mutations and guiding therapy.

Imaging Gigantic Small Bowel Gastrointestinal Stromal Tumours Through Different Radiological Lenses: A Case Report

Gastrointestinal stromal tumours (GIST) account for 1–3% of all the gastrointestinal (GI) neoplasms. It is the most common mesenchymal tumour in the Gl tract. The majority of GISTs are KIT gene positive; however, it is necessary to diagnose them pre-operatively. Here, the authors report the case of a 65-year-old male who presented with pain and a lump in the umbilical region for the last 2 years. On abdominal ultrasound, there was a heterogeneously hypoechoic mass in the umbilical region, with lobulated margins and central necrotic areas. On small bowel series, the core of the mass showed faint contrast opacification. Contrast-enhanced CT of the abdomen showed a heterogeneously enhancing, lobulated exophytic lesion arising from the small bowel loops, the central core of the lesion demonstrating an air-contrast level. Under ultrasound guidance, the lesion was biopsied. Histopathological findings were suggestive of a spindle cell tumour. The sample was c-KIT positive. Hence, the diagnosis of GIST was confirmed. The patient was given imatinib after resection of the mass. Usually, a GIST of larger size has higher malignant and metastatic potential; however, this article shows a gigantic small bowel GIST with cavitation and heterogeneity in different imaging modality, and still has no metastasis on imaging or high mitotic activity, and nuclear atypia on histopathology. A radiologist should also know the imaging pattern on conventional imaging and ultrasound, apart from usual cross-sectional imaging.