Introduction: While uterine leiomyosarcoma, an aggressive smooth muscle malignancy, has a strong propensity for hematogenous spread—most commonly to the lungs and liver—gastric metastasis remains exceedingly rare. When it occurs, it presents as a masquerading lesion that mimics primary gastric tumors, creating a significant diagnostic pitfall for both clinicians and pathologists. Case Description: A 75-year-old female presented with recurrent melena. Esophagogastroduodenoscopy revealed a friable, bell-shaped mass measuring 7 × 6 cm in the gastric fundus, suspicious for GIST. Histopathology showed spindle to epithelioid tumor cells arranged in intersecting fascicles and solid sheets with vesicular nuclei, conspicuous nucleoli, numerous mitosis, and tumor necrosis. IHCs demonstrated strong SMA positivity but negative CD117, raising consideration of undifferentiated GIST. However, subsequent DOG1 staining was negative, arguing strongly against GIST. Additional markers including S100, PanCK, CD3, CD20, CD15, and CD30 were negative. Further IHCs revealed diffuse, desmin and H-caldesmon positivity, supporting smooth muscle differentiation. Review of prior records revealed TAHBSO in 2023 for uterine leiomyosarcoma. Discussion: Metastatic involvement of the stomach is rare and most commonly arises from breast or lung primaries. Gastric metastases are rare and most commonly originate from breast or lung primaries. Metastatic uterine leiomyosarcoma presenting as a solitary gastric mass is exceedingly uncommon and may closely mimic primary gastric tumors such as GIST both endoscopically and histologically, representing an important diagnostic pitfall. Conclusion This case highlights a rare metastatic pattern of uterine leiomyosarcoma presenting as an overt gastric mass with GI bleeding. Awareness of this deceptive presentation and careful clinicopathologic correlation are essential for accurate diagnosis. To our knowledge, this represents one of the few reported cases worldwide and possibly the first documented in the Philippines.
Gastrointestinal Stromal Tumors ; Immunohistochemistry ; Leiomyosarcoma ; Gastrointestinal Hemorrhage

OBJECTIVES: There is currently no consensus on whether extra-gastrointestinal stromal tumors (EGISTs) and gastrointestinal stromal tumors (GISTs) are the same type of tumor, and whether the diagnosis and treatment of EGISTs can directly replicate the current diagnostic and treatment standards for GISTs. This study aims to further elucidate the clinical and pathological characteristics, diagnosis, treatment, and prognosis of EGISTs by analyzing the research results of domestic scholars in the field of EGISTs in the past decade. METHODS: A review was conducted on original Chinese and English research articles published from 2013 to 2022 focusing on EGISTs. A descriptive approach was used to extract key information from the literature, including patient demographics, tumor location, tumor diameter, mitotic figures, risk stratification, immunohistochemical markers, cell type, and prognostic factors. The data were subjected to statistical analysis. RESULTS: A total of 12 articles containing 780 EGIST patients were included. The male-to-female incidence of EGISTs was 0.92꞉1. The most common sites of EGISTs were mesentery (30.96%), peritoneum or retroperitoneum (28.53%), omentum (20.32%), and pelvic cavity (12.52%). 52.77% of EGISTs had tumor diameters greater than 10 cm, and the proportions of EGISTs with nuclear fission patterns greater than 5/50 high power field (HPF) and greater than 10/50 HPF were 51.24% and 26.11%, respectively. The proportion of high-risk EGISTs was 79.05%. The positive rates of immune markers CD117, CD34, and DOG-1 in EGISTs were 82.3%, 69.0%, and 79.5%, respectively. The proportion of Ki-67 >5% was 49.2%, and the proportion of Ki-67 >10% was 24.8%. The proportions of EGISTs in spindle cells, epithelial cells, and mixed cells were 74.4%, 14.8%, and 13.1%, respectively. The diameter of the tumor, resection method, risk level, Ki-67 index, mitotic counts, presence of rupture/bleeding/necrosis/peripheral tissue invasion/recurrence and metastasis, as well as the use of imatinib treatment after surgery were important factors affecting the prognosis of EGISTs. CONCLUSIONS Current medical research is relatively well cognizant of GISTs with primary sites in the gastrointestinal tract. Compared with GISTs, EGISTs have large tumor diameters, high mitotic counts, a high percentage of high-risk grades, relatively unique molecular expression, and high aggressiveness. EGISTs differ from GISTs in clinicopathological characteristics. Whether EGISTs and GISTs share a common origin remains unclear. If they are distinct tumor entities, separate diagnostic and treatment guidelines for EGISTs should be established. If EGISTs are ultimately confirmed to be a special subtype of GISTs, then directly applying existing GIST-based standards to EGISTs may be inappropriate. A more scientific approach would involve subclassifying EGISTs based on anatomical location and then tailoring treatment strategies accordingly with reference to GIST guidelines.
Humans ; Gastrointestinal Stromal Tumors/epidemiology* ; Male ; Female ; Prognosis ; Proto-Oncogene Proteins c-kit/metabolism*

Objective: To investigate the clinical significance of pathological diagnosis and genetic abnormalities detection of gastrointestinal stromal tumor (GIST) using endoscopic biopsy. Methods: Patients with GIST diagnosed by endoscopic biopsy (from January 1st, 2016 to August 1st, 2018, at Zhongshan Hospital, Fudan University) were included in this study. This retrospective study evaluated the histopathologic and immunohistochemical (IHC) features, genetic abnormalities of the tumors and the treatment and clinical course of the patients. Results: Totally 4 095 cases of GIST were collected, among which 67 patients (67/4 095, 1.6%) underwent endoscopic biopsy. Forty-eight patients (71.6%) were male and 19 (28.4%) were female, with a mean age of 61 years (range 31-90 years). Fifty-nine lesions were located in stomach and eight in duodenum. Of all the 67 cases, 47 were spindle type, 14 were epithelioid type, and 6 mixed type. IHC staining showed the positive rates were 100.0% (64/64) for DOG1, 98.4% (62/63) for CD117, 87.5% (56/64) for CD34, 3.6% (2/56) for S-100 protein, 12.1% (7/58) for α-SMA, 12.3% (7/57) for desmin and 4.0% (2/50) for CKpan. Morphologically, 34 cases were malignant; three cases (all epithelioid type) were originally misdiagnosed as poorly differentiated carcinoma; missed-diagnosis were found in four cases (spindle type) due to the insufficient diagnostic tumor cells. The genetic abnormality detection rate in the biopsy tissue was 38.8% (26/67),among them two patients were lost to follow up after biopsy, 33 patients received surgical resection, 16 cases underwent operation after neoadjuvant therapy and 16 patients with advanced disease underwent continuous imatinib therapy, with the genetic testing rate of 6.1% (2/33), 10/16 and 14/16, respectively. Conclusions: Endoscopic biopsy is a useful but rare method for the preoperative diagnosis of GIST. For majority of biopsy, accurate pathological diagnosis and auxiliary examination can be completed to guide clinical treatment. A thorough history in combination with endoscopic finding is essential to avoid misdiagnosis (epithelioid type) and missed diagnosis (spindle type) in suspicious cases. Genetic testing should be recommended in patients who will undergo targeted therapy after endoscopic biopsy, and it can provide valuable information and guidance for clinical treatment.
Humans ; Male ; Female ; Adult ; Middle Aged ; Aged ; Aged, 80 and over ; Gastrointestinal Stromal Tumors/pathology* ; Retrospective Studies ; Clinical Relevance ; Imatinib Mesylate ; Biopsy ; S100 Proteins

Objective: To investigate the clinicopathological features, treatment and prognosis of gastric intermediate-risk gastrointestinal stromal tumor (GIST), so as to provide a reference for clinical management and further research. Methods: A retrospective observational study of patients with gastric intermediate-risk GIST, who underwent surgical resection between January 1996 and December 2019 at Zhongshan Hospital of Fudan University, was carried out. Results: Totally, 360 patients with a median age of 59 years were included. There were 190 males and 170 females with median tumor diameter of 5.9 cm. Routine genetic testing was performed in 247 cases (68.6%, 247/360), and 198 cases (80.2%) showed KIT mutation, 26 cases (10.5%) showed PDGFRA mutation, and 23 cases were wild-type GIST. According to "Zhongshan Method"(including 12 parameters), there were 121 malignant and 239 non-malignant cases. Complete follow-up data were available in 241 patients; 55 patients (22.8%) received imatinib therapy, 10 patients (4.1%) experienced tumor progression, and one patient (PDGFRA mutation, 0.4%) died. Disease-free survival (DFS) and overall survival rate at 5 years was 96.0% and 99.6%, respectively. Among the intermediate-risk GIST, there was no difference in DFS between the overall population, KIT mutation, PDGFRA mutation, wild-type, non-malignant and malignant subgroups (all P>0.05). However, the non-malignancy/malignancy analysis showed that there were significant differences in DFS among the overall population (P<0.01), imatinib treatment group (P=0.044) and no imatinib treatment group (P<0.01). Adjuvant imatinib resulted in potential survival benefit for KIT mutated malignant and intermediate-risk GIST in DFS (P=0.241). Conclusions: Gastric intermediate-risk GIST shows a heterogeneous biologic behavior spectrum from benign to highly malignant. It can be further classified into benign and malignant, mainly nonmalignant and low-grade malignant. The overall disease progression rate after surgical resection is low, and real-world data show that there is no significant benefit from imatinib treatment after surgery. However, adjuvant imatinib potentially improves DFS of intermediate-risk patients with tumors harboring KIT mutation in the malignant group. Therefore, a comprehensive analysis of gene mutations in benign/malignant GIST will facilitate improvements in therapeutic decision-making.
Male ; Female ; Humans ; Middle Aged ; Gastrointestinal Stromal Tumors/surgery* ; Retrospective Studies ; Antineoplastic Agents/therapeutic use* ; Prognosis ; Imatinib Mesylate/therapeutic use* ; Mutation ; Proto-Oncogene Proteins c-kit/genetics*

Objective: To analyze the clinicopathological features and gene mutations of primary gastrointestinal stromal tumors (GISTs) of the stomach and intestine and the prognosis of intermediate- and high-risk GISTs. Methods: This was a retrospective cohort study. Data of patients with GISTs admitted to Tianjin Medical University Cancer Institute and Hospital from January 2011 to December 2019 were collected retrospectively. Patients with primary gastric or intestinal disease who had undergone endoscopic or surgical resection of the primary lesion and were confirmed pathologically as GIST were included. Patients treated with targeted therapy preoperatively were excluded. The above criteria were met by 1061 patients with primary GISTs, 794 of whom had gastric GISTs and 267 intestinal GISTs. Genetic testing had been performed in 360 of these patients since implementation of Sanger sequencing in our hospital in October 2014. Gene mutations in KIT exons 9, 11, 13, and 17 and PDGFRA exons 12 and 18 were detected by Sanger sequencing. The factors investigated in this study included: (1) clinicopathological data, such as sex, age, primary tumor location, maximum tumor diameter, histological type, mitotic index (/5 mm²), and risk classification; (2) gene mutation; (3) follow-up, survival, and postoperative treatment; and (4) prognostic factors of progression-free survival (PFS) and overall survival (OS) for intermediate- and high-risk GIST. Results: (1) Clinicopathological features: The median ages of patients with primary gastric and intestinal GIST were 61 (8-85) years and 60 (26-80) years, respectively; The median maximum tumor diameters were 4.0 (0.3-32.0) cm and 6.0 (0.3-35.0) cm, respectively; The median mitotic indexes were 3 (0-113)/5 mm² and 3 (0-50)/5 mm², respectively; The median Ki-67 proliferation indexes were 5% (1%-80%) and 5% (1%-50%), respectively. The rates of positivity for CD117, DOG-1, and CD34 were 99.7% (792/794), 99.9% (731/732), 95.6% (753/788), and 100.0% (267/267), 100.0% (238/238), 61.5% (163/265), respectively. There were higher proportions of male patients (χ²=6.390, P=0.011), tumors of maximum diameter > 5.0 cm (χ²=33.593, P<0.001), high-risk (χ²=94.957, P<0.001), and CD34-negativity (χ²=203.138, P<0.001) among patients with intestinal GISTs than among those with gastric GISTs. (2) Gene mutations: Gene mutations were investigated in 286/360 patients (79.4%) with primary gastric GISTs and 74/360 (20.6%) with primary intestinal GISTs. Among the 286 patients with gastric primary GISTs, 79.4% (227/286), 8.4% (24/286), and 12.2% (35/286), had KIT mutations, PDGFRA mutations, and wild-type, respectively. Among the 74 patients with primary intestinal GISTs, 85.1% (63/74) had KIT mutations and 14.9% (11/74) were wild-type. The PDGFRA mutation rate was lower in patients with intestinal GISTs than in those with gastric GISTs[ 0% vs. 8.4%(24/286), χ²=6.770, P=0.034], whereas KIT exon 9 mutations occurred more often in those with intestinal GISTs [22.2% (14/63) vs. 1.8% (4/227), P<0.001]. There were no significant differences between gastric and intestinal GISTs in the rates of KIT exon 11 mutation type and KIT exon 11 deletion mutation type (both P>0.05). (3) Follow-up, survival, and postoperative treatment: After excluding 228 patients with synchronous and metachronous other malignant tumors, the remaining 833 patients were followed up for 6-124 (median 53) months with a follow-up rate of 88.6% (738/833). None of the patients with very low or low-risk gastric (n=239) or intestinal GISTs (n=56) had received targeted therapy postoperatively. Among 179 patients with moderate-risk GISTs, postoperative targeted therapy had been administered to 88/155 with gastric and 11/24 with intestinal GISTs. Among 264 patients with high-risk GISTs, postoperative targeted therapy had been administered to 106/153 with gastric and 62/111 with intestinal GISTs. The 3-, 5-, and 10-year PFS of patients with gastric or intestinal GISTs were 96.5%, 93.8%, and 87.6% and 85.7%, 80.1% and 63.3%, respectively (P<0.001). The 3-, 5-, and 10-year OS were 99.2%, 98.8%, 97.5% and 94.8%, 92.1%, 85.0%, respectively (P<0.001). (4) Analysis of predictors of intermediate- and high-risk GISTs: The 5-year PFS of patients with gastric and intestinal GISTs were 89.5% and 73.2%, respectively (P<0.001); The 5-year OS were 97.9% and 89.3%, respectively (P<0.001). Multivariate analysis showed that high risk (HR=2.918, 95%CI: 1.076-7.911, P=0.035) and Ki-67 proliferation index > 5% (HR=2.778, 95%CI: 1.389-5.558, P=0.004) were independent risk factors for PFS in patients with intermediate- and high-risk GISTs (both P<0.05). Intestinal GISTs (HR=3.485, 95%CI: 1.407-8.634, P=0.007) and high risk (HR=3.753,95%CI:1.079-13.056, P=0.038) were independent risk factors for OS in patients with intermediate- and high-risk GISTs (both P<0.05). Postoperative targeted therapy was independent protective factor for PFS and OS (HR=0.103, 95%CI: 0.049-0.213, P<0.001; HR=0.210, 95%CI:0.078-0.564,P=0.002). Conclusions: Primary intestinal GIST behaves more aggressively than gastric GISTs and more frequently progress after surgery. Moreover, CD34 negativity and KIT exon 9 mutations occur more frequently in patients with intestinal GISTs than in those with gastric GISTs.
Male ; Humans ; Gastrointestinal Stromal Tumors/surgery* ; Retrospective Studies ; Ki-67 Antigen ; Stomach Neoplasms/pathology* ; Prognosis ; Mutation ; Intestines/pathology* ; Proto-Oncogene Proteins c-kit/genetics* ; Receptor, Platelet-Derived Growth Factor alpha/genetics*

Objective: To analyze the clinicopathological characteristics and prognosis of patients with small bowel tumors. Methods: This was a retrospective, observational study. We collected clinicopathological data of patients with primary jejunal or ileal tumors who had undergone small bowel resection in the Department of Gastrointestinal Surgery, West China Hospital, Sichuan University between January 2012 and September 2017. The inclusion criteria included: (1) older than 18 years; (2) had undergone small bowel resection; (3) primary location at jejunum or ileum; (4) postoperative pathological examination confirmed malignancy or malignant potential; and (5) complete clinicopathological and follow-up data. Patients with a history of previous or other concomitant malignancies and those who had undergone exploratory laparotomy with biopsy but no resection were excluded. The clinicopathological characteristics and prognoses of included patients were analyzed. Results: The study cohort comprised 220 patients with small bowel tumors, 136 of which were classified as gastrointestinal stromal tumors (GISTs), 47 as adenocarcinomas, and 35 as lymphomas. The median follow-up for all patient was 81.0 months (75.9-86.1). GISTs frequently manifested as gastrointestinal bleeding (61.0%, 83/136) and abdominal pain (38.2%, 52/136). In the patients with GISTs, the rates of lymph node and distant metastasis were 0.7% (1/136) and 11.8% (16/136), respectively. The median follow-up time was 81.0 (75.9-86.1) months. The 3-year overall survival (OS) rate was 96.3%. Multivariate Cox regression-analysis results showed that distant metastasis was the only factor associated with OS of patients with GISTs (HR=23.639, 95% CI: 4.564-122.430, P<0.001). The main clinical manifestations of small bowel adenocarcinoma were abdominal pain (85.1%, 40/47), constipation/diarrhea (61.7%, 29/47), and weight loss (61.7%, 29/47). Rates of lymph node and distant metastasis in patients with small bowel adenocarcinoma were 53.2% (25/47) and 23.4% (11/47), respectively. The 3-year OS rate of patients with small bowel adenocarcinoma was 44.7%. Multivariate Cox regression-analysis results showed that distant metastasis (HR=4.018, 95%CI: 2.108-10.331, P<0.001) and adjuvant chemotherapy (HR=0.291, 95% CI: 0.140-0.609, P=0.001) were independently associated with OS of patients with small bowel adenocarcinoma. Small bowel lymphoma frequently manifested as abdominal pain (68.6%, 24/35) and constipation/diarrhea (31.4%, 11/35); 77.1% (27/35) of small bowel lymphomas were of B-cell origin. The 3-year OS rate of patients with small bowel lymphomas was 60.0%. T/NK cell lymphomas (HR= 6.598, 95% CI: 2.172-20.041, P<0.001) and adjuvant chemotherapy (HR=0.119, 95% CI: 0.015-0.925, P=0.042) were independently associated with OS of patients with small bowel lymphoma. Small bowel GISTs have a better prognosis than small intestinal adenocarcinomas (P<0.001) or lymphomas (P<0.001), and small bowel lymphomas have a better prognosis than small bowel adenocarcinomas (P=0.035). Conclusions: The clinical manifestations of small intestinal tumor are non-specific. Small bowel GISTs are relatively indolent and have a good prognosis, whereas adenocarcinomas and lymphomas (especially T/NK-cell lymphomas) are highly malignant and have a poor prognosis. Adjuvant chemotherapy would likely improve the prognosis of patients with small bowel adenocarcinomas or lymphomas.
Humans ; Prognosis ; Intestinal Neoplasms/diagnosis* ; Duodenal Neoplasms ; Gastrointestinal Stromal Tumors ; Lymphoma ; Adenocarcinoma/surgery* ; Constipation ; Abdominal Pain ; Retrospective Studies

Tyrosine kinase inhibitors (TKI) significantly reduce the risk of recurrence and metastasis and prolong survival in patients with gastrointestinal stromal tumors (GIST), but drug resistance is often inevitable. Immunotherapy has been proven effective in multiple solid tumors, but the efficacy in GIST is unclear. The efficacy of immunotherapy depends on the tumor microenvironment (TME). Tumor-infiltrating immune cells and immune checkpoints are important components of TME, which not only participate in the regulation of tumor immune response but are also the key target of immunotherapy. A comprehensive analysis of them can clarify the mechanism of tumor immune escape. This review found that there are abundant tumor-infiltrating immune cells in GIST, which play an important role in tumor immune surveillance and escape. Although early clinical studies have shown that patients with GIST have a good tolerance to immunotherapy, the curative effect is not satisfactory. Therefore, how to select the responders of immunotherapy and coordinate the relationship between immunotherapy and TKIs is the key issue to be explored. At the same time, the gradual deepening of basic research and large sample prospective clinical trials will certainly provide more strategies for the application of immunotherapy in GIST.
Humans ; Gastrointestinal Stromal Tumors/drug therapy* ; Prospective Studies ; Immunotherapy/methods* ; Tumor Microenvironment ; Protein Kinase Inhibitors/pharmacology*

Gastrointestinal Stromal Tumors/pathology* ; Heart Ventricles/pathology* ; Humans ; Liver Neoplasms ; Tomography, X-Ray Computed

Objective To investigate the performance of the combined model based on both clinicopathological features and CT texture features in predicting liver metastasis of high-risk gastrointestinal stromal tumors(GISTs). Methods The high-risk GISTs confirmed by pathology from January 2015 to December 2020 were analyzed retrospectively,including 153 cases from the Cancer Hospital of the University of Chinese Academy of Sciences and 51 cases from the Shaoxing Central Hospital.The cases were randomly assigned into a training set(n=142)and a test set(n=62)at a ratio of 7∶3.According to the results of operation or puncture,they were classified into a liver metastasis group(76 cases)and a non-metastasis group(128 cases).ITK-SNAP was employed to delineate the volume of interest of the stromal tumors.Least absolute shrinkage and selection operator(LASSO)was employed to screen out the effective features.Multivariate logistic regression was adopted to construct the models based on clinicopathological features,texture features extracted from CT scans,and the both(combined model),respectively.Receiver operating characteristic(ROC)curve and calibration curve were established to evaluate the predictive performance of the models.The area under the curve(AUC)was compared by Delong test. Results Body mass index(BMI),tumor size,Ki-67,tumor occurrence site,abdominal mass,gastrointestinal bleeding,and CA125 level showed statistical differences between groups(all P<0.05).A total of 107 texture features were extracted from CT images,from which 13 and 7 texture features were selected by LASSO from CT plain scans and CT enhanced scans,respectively.The AUC of the prediction with the training set and the test set respectively was 0.870 and 0.855 for the model based on clinicopathological features,0.918 and 0.836 for the model based on texture features extracted from CT plain scans,0.920 and 0.846 for the model based on texture features extracted from CT enhanced scans,and 0.930 and 0.889 for the combined model based on both clinicopathological features and texture features extracted from CT plain scans.Delong test demonstrated no significant difference in AUC between the models based on the texture features extracted from CT plain scans and CT enhanced scans(P=0.762),whereas the AUC of the combined model was significantly different from that of the clinicopathological feature-based model and texture feature-based model(P=0.001 and P=0.023,respectively). Conclusion Texture features extracted from CT plain scans can predict the liver metastasis of high-risk GISTs,and the model established with clinicopathological features combined with CT texture features has best prediction performance.
Gastrointestinal Stromal Tumors/diagnostic imaging* ; Humans ; Liver Neoplasms/diagnostic imaging* ; ROC Curve ; Retrospective Studies ; Tomography, X-Ray Computed/methods*

Gastrointestinal Stromal Tumors/pathology* ; Humans ; Proto-Oncogene Proteins c-kit/genetics*