Chinese consensus guidelines for diagnosis and management of gastrointestinal stromal tumor

In order to further promote the standardization of diagnosis and treatment of gastrointestinal stromal tumor （GIST） in China, the members of Chinese Society of Clinical Oncology （CSCO） Expert Committee on GIST thoroughly discussed the key contents of the consensus guidelines, and voted on the controversial issue. In final, the Chinese consensus guidelines for the diagnosis and management of GIST （2017 edition） was formed on the basis of 2013 edition consensus guidelines, which is hereby announced. The consensus included the pathological diagnosis, recurrence risk classification evaluation, targeted agent therapy, surgery and principles of surveillance of GIST.

Endoscopic en bloc resection of an exophytic gastrointestinal stromal tumor with suction excavation technique

Here, we report the first successful endoscopic resection of an exophytic gastrointestinal stromal tumor (GIST) using a novel perforation-free suction excavation technique. A 49-year-old woman presented for further management of a gastric subepithelial tumor on the lesser curvature of the lower body, originally detected via routine upper gastrointestinal endoscopy. Abdominal computed tomography and endoscopic ultrasound showed a 4-cm extraluminally protruding mass originating from the muscularis propria layer. The patient firmly refused surgical resection owing to potential cardiac problems, and informed consent was obtained for endoscopic removal. Careful dissection and suction of the tumor was repeated until successful extraction was achieved without serosal injury. We named this procedure the suction excavation technique. The tumor’s dimensions were 3.5 cm × 2.8 cm × 2.5 cm. The tumor was positive for C-KIT and CD34 by immunohistochemical staining. The mitotic count was 6/50 high-power fields. The patient was followed for 5 years without tumor recurrence. This case demonstrated the use of endoscopic resection of an exophytic GIST using the suction excavation technique as a potential therapy without surgical resection.

Gastric schwannoma misdiagnosed as gastrointestinal stromal tumor by ultrasonography before surgery:A case report

BACKGROUND Gastric origin tumors were diagnosed and evaluated preoperatively by gastroscopy,endoscopic ultrasonography,computed tomography(CT)or magnetic resonance imaging.Currently,transabdominal high-resolution ultrasound combined with gastrointestinal contrast agent can be used to diagnose stomach tumors effectively and without invasive procedures or radiation.However,although an appreciable number of cases of gastric schwannoma(GS)have been reported since the first description of such in 1988,the ongoing lack of a comprehensive list of ultrasonic characteristics has limited the accuracy of preoperative ultrasound diagnosis.CASE SUMMARY A 64-year-old female patient presented to our hospital with dizziness and head discomfort.During an abdominal ultrasound,a hypoechoic gastric mass was found,having clear and regular boundaries and no observable blood flow.Based on these characteristics,a gastrointestinal stromal tumor was suspected.Results from an endoscopic ultrasound biopsy and accompanying immunohistochemical analysis,coupled with abdominal CT findings indicating lymph node enlargement around the stomach,led to diagnosis of GS but did not exclude malignancy.After surgical resection of the tumor,the final diagnosis of GS without lymph node metastasis was made.No recurrence has occurred in the 6 years of follow-up.CONCLUSION A clearly defined ultrasonic characteristic profile of GS is important to improve diagnostic accuracy.

Efficacy of endoscopic ultrasound in the evaluation of small gastrointestinal stromal tumors

BACKGROUND Gastrointestinal stromal tumors(GISTs)with a diameter of<2 cm are called small GISTs.Currently,endoscopic ultrasound(EUS)is widely used as a regular followup method for GISTs,which can also provide a preliminary basis for judging the malignancy potential of lesions.However,there are no studies on the accuracy of EUS to assess the malignant potential of small GISTs.AIM To evaluate the efficacy of EUS in the diagnosis and risk assessment of small GISTs.METHODS We collected data from patients with small GISTs who were admitted to Shengjing Hospital of China Medical University between October 2014 and July 2019.The accurate diagnosis and risk classifications of patients were based on the pathological assessment according to the modified National Institute of Health criteria after endoscopic resection or laparoscopic surgery.Preoperative EUS features(marginal irregularity,cystic changes,homogeneity,ulceration,and strong echogenic foci)were retrospectively analyzed.The assessment results based on EUS features were compared with the pathological features.RESULTS A total of 256 patients(69 men and 187 women)were enrolled.Pathological results included 232,16,7,and 1 very low-,low-,intermediate-,and high-risk cases,respectively.The most frequent tumor location was the gastric fundus(78.1%),and mitoses were calculated as>5/50 high power field in 8(3.1%)patients.Marginal irregularity,ulceration,strong echo foci,and heterogeneity were detected in 1(0.4%),2(0.8%),22(8.6%),and 67(65.1%)patients,respectively.However,cystic changes were not detected.Tumor size was positively correlated with the mitotic index(P<0.001).Receiver operating curve analysis identified 1.48 cm as the best cut-off value to predict malignant potential(95%confidence interval:0.824–0.956).EUS heterogeneity with tumor diameters>1.48 cm was associated with higher risk classification(P<0.05).CONCLUSION Small GISTs(diameters>1.48 cm)with positive EUS features should receive intensive surveillance or undergo endoscopic surgery.EUS and dissection are efficient diagnostic and therapeutic approaches for small GISTs.

Effectiveness and safety of endoscopic resection for duodenal gastrointestinal stromal tumors:A single center analysis

BACKGROUND Endoscopic resection for duodenal gastrointestinal stromal tumors(GISTs)is still considered a great challenge with a high risk of complications,including perforation,bleeding,tumor rupture,and residual tumor.AIM To assess the effectiveness and safety of endoscopic resection for duodenal GISTs.METHODS Between January 2010 and January 2022,11 patients with duodenal GISTs were treated with endoscopic resection.Data were extracted for the incidence of complete resection,bleeding,perforation,postoperative infection,recurrence,and distant metastasis.RESULTS The incidence of successful complete resection of duodenal GISTs was 100%.Three cases(27.3%)had suspected positive margins,and the other 8 cases(72.7%)had negative vertical and horizontal margins.Perforation occurred in all 11 patients.The success rate of perforation closure was 100%,while 1 patient(9.1%)had suspected delayed perforation.All bleeding during the procedure was managed by endoscopic methods.One case(9.1%)had delayed bleeding.Postoperative infection occurred in 6 patients(54.5%),including 1 who developed septic shock and 1 who developed a right iliac fossa abscess.All 11 patients recovered and were discharged.The mean hospital stay was 15.3 d.During the follow-up period(14-80 mo),duodenal stenosis occurred in 1 case(9.1%),and no local recurrence or distant metastasis were detected.CONCLUSION Endoscopic resection for duodenal GISTs appears to be an effective and safe minimally invasive treatment when performed by an experienced endoscopist.

Long-term outcomes of endoscopic resection for small(≤4.0cm) gastric gastrointestinal stromal tumors originating from the muscularis propria layer

AIM To evaluate the long-term efficacy of endoscopic resection(ER) for small(≤ 4.0 cm) gastric gastrointestinal stromal tumors(GISTs) originating from the muscularis propria layer.METHODS Between June 2005 and February 2015, we retrospectively analyzed 229 consecutive patients with gastric MP-GISTs who underwent ER with a follow-up at least 36 mo. The main outcome measurements included complete resection rate, complications, and long-term follow-up outcomes.RESULTS ER included endoscopic muscularis excavation in 179 cases, endoscopic full-thickness resection in 32 cases, and submucosal tunneling endoscopic resection in 18 cases. The median size of GISTs was 1.90 cm. Of the 229 GISTs, 147 were very low risk, 72 were low risk, 8 were intermediate risk, and 2 were high risk. Shortterm outcomes showed the complete resection rate was 96.5%, and 8 patients(3.5%) had complications. Of the 8 patients with complications, only one patient required surgical intervention. Long-term outcomes showed 225 patients were actively followed-up until composition of this manuscript. The remaining 4 patients were lost because of unrelated death. During the follow-up period(median, 57 mo), no residual, recurrent lesions, or distant metastasis were detected in any patients. Binary logistic regression analysis showed tumor size was a risk factor associated with a high mitotic index(≥ 5/50 HPF) of GISTs(P = 0.002).CONCLUSION ER seems to be an effective and safe method for gastric MP-GISTs ≤ 4.0 cm, and, for some intermediate or high risk GISTs, adjuvant therapy and/or additional surgery might be required to reduce the risk of recurrence or metastasis.

Comparison between air and carbon dioxide insufflation in the endoscopic submucosal excavation of gastrointestinal stromal tumors

AIM:To evaluate the safety and efficacy of CO2 insufflation compared with air insufflation in the endoscopic submucosal excavation(ESE) of gastrointestinal stromal tumors.METHODS:Sixty patients were randomized to undergo endoscopic submucosal excavation,with the CO2 group(n = 30) and the air group(n = 30) undergoingCO2 insufflation and air insufflation in the ESE,respectively.The end-tidal CO2 level(pETCO2) was observed at 4 time points:at the beginning of ESE,at total removal of the tumors,at completed wound management,and 10 min after ESE.Additionally,the patients' experience of pain at 1,3,6 and 24 h after the examination was registered using a visual analog scale(VAS).RESULTS:Both the CO2 group and air group were similar in mean age,sex,body mass index(all P > 0.05).There were no significant differences in PetCO2 values before and after the procedure(P > 0.05).However,the pain scores after the ESE at different time points in the CO2 group decreased significantly compared with the air group(1 h:21.2 ± 3.4 vs 61.5 ± 1.7;3 h:8.5 ± 0.7 vs 42.9 ± 1.3;6 h:4.4 ± 1.6 vs 27.6 ± 1.2;24 h:2.3 ± 0.4 vs 21.4 ± 0.7,P < 0.05).Meanwhile,the percentage of VAS scores of 0 in the CO2 group after 1,3,6 and 24 h was significantly higher than that in the air group(60.7 ± 1.4 vs 18.9 ± 1.5,81.5 ± 2.3 vs 20.6 ± 1.2,89.2 ± 0.7 vs 36.8 ± 0.9,91.3 ± 0.8 vs 63.8 ± 1.3,respectively,P < 0.05).Moreover,the condition of the CO2 group was better than that of the air group with respect to anal exsufflation.CONCLUSION:Insufflation of CO2 in the ESE of gastrointestinal stromal tumors will not cause CO2 retention and it may significantly reduce the level of pain,thus it is safe and effective.

Clinical presentations of gastric small gastrointestinal stromal tumors mimics functional dyspepsia symptoms

AIM: To explore whether clinical presentations of gastric small gastrointestinal tumors (GISTs) mimics gastrointestinal dyspepsia symptoms.

GASTROINTESTINAL STROMAL TUMORS OF THE ANORECTUM——A SPECIAL ENTITY: GISTs OF THE ANORECTUM

Objective： Until recently gastrointestinal stromal tumor （GIST） has been separated from other mesenchymal neoplasms and categorized as a special entity. Morphology of tumor cells and immunohistochemical findings with CD117 are crucial in the pathological diagnosis of GISTs. Newly developed drug imatinib mesylate （formerly called STI571） has been proved effective for GISTs. The distinction of GISTs and other mesenchymal tumors has great clinical significance, especially for lesions located in the anorectum. Methods： The authors searched the database of Peking University, School of Ontology for patients with anorectal neoplasms treated from January 1995 to June 2002. Information of 12 patients with anorectal mesenchymal tumors was collected. The patients were reevaluated and discussed according to current criteria of GISTs with clinical data and immunohistochemical findings. Results： Six patients （including 3 males） were finally diagnosed as anorectal GISTs. The median age of those patients was 59.5 years （27～69）. The symptoms were not specific. Three cases with original diagnosis of leiomyoma or leiomyosarcoma were actually GISTs. A total of six anorectal GISTs was found comprising about 1.06% of patients with anorectal neoplasmas in the same period. Besides CD117, CD34 and vimentin were also expressed in majority of these patients. Five of the six patients underwent surgical resection one of which received neoadjuvant chemotherapy before resection Conclusion： Anorectal GISTs should be considered as a special entity using current diagnostic criteria. Surgical resection remains the primary therapeutic strategy. Neoadjuvant imatinib mesylate may be helpful in sphincter-sparing operations and improvement of the quality of life for these patients.

Gastroduodenal intussusception caused by gastric gastrointestinal stromal tumor:A case report and review of the literature

BACKGROUND Gastric gastrointestinal stromal tumor(GIST)is the most common etiology of gastroduodenal intussusception.Although gastroduodenal intussusception caused by gastric GIST is mostly treated by surgical resection,the first case of gastroduodenal intussusception caused by gastric GIST was treated by endoscopic submucosal dissection(ESD)in Japan in 2017.CASE SUMMARY An 84-year-old woman presented with symptoms of postprandial fullness with nausea and occasional vomiting for a month.Initially,she visited a local clinic for help,where abdominal sonography revealed a space-occupying lesion around the liver,so she was referred to our hospital for further confirmation.Abdominal sonography was repeated,which revealed a mass with an alternating concentric echogenic lesion.Esophagogastroduodenoscopy(EGD)was performed under the initial impression of gastric cancer with central necrosis and showed a tortuous distortion of gastric folds down from the lesser curvature side to the duodenal bulb with stenosis of the gastric outlet.EGD was barely passed through to the 2nd portion of the duodenum and a friable ulcerated mass was found.Several differential diagnoses were suspected,including gastroduodenal intussusception,gastric cancer invasion to the duodenum,or pancreatic cancer with adherence to the gastric antrum and duodenum.Abdominal computed tomography for further evaluation was arranged and showed gastroduodenal intussusception with a long stalk polypoid mass 5.9 cm in the duodenal bulb.Under the impression of gastroduodenal intussusception,ESD was performed at the base of the gastroduodenal intussusception;unfortunately,a gastric perforation was found after complete resection was accomplished,so gastrorrhaphy was performed for the perforation and retrieval of the huge polypoid lesion.The gastric tumor was pathologically proved to be a GIST.After the operation,there was no digestive disturbance and the patient was discharged uneventfully on the 10th day following the operation.CONCLUSION We present the second case of gastroduodenal intussusception caused by GIST treated by ESD.It is also the first case report of gastroduodenal intussusception by GIST in Taiwan,and endoscopic reduction or resection is an alternative treatment for elderly patients who are not candidates for surgery.

Synchronous occurrence of gastric cancer and gastrointestinal stromal tumor: A case report and review of the literature

BACKGROUND To evaluate the clinicopathological features and prognosis of gastric cancer(GC)occurring synchronously with gastrointestinal stromal tumor(GIST).CASE SUMMARY We report 19 patients with concurrent GC and GIST(17 male and 2 female,median age 62 years).GC was most often located in the lower third of the stomach.GIST was diagnosed preoperatively in four patients.GIST was most often located in the gastric body(n=8,42%).The most common growth pattern in GIST was extraluminal(n=12,63%).The positive expression rates of CD117 and CD34 in GIST were 100% and 95%,respectively.Most patients with GIST(n=17,89%)were very low or low risk.There was no recurrence of GIST during follow-up.The 3-year cumulative survival rate was 73.9%,and the 5-year cumulative survival rate was 59.2%.The combined analysis of this study and literature reports(47 reports,157 patients)found that GC and GIST were usually located in the lower third(42%)and middle third(51%)of the stomach.GC was usually early(stage I:42%),poorly differentiated(42%)intestinal-type adenocarcinoma(51%).GISTs were primarily small in diameter(median:1.2 cm)and very low or low risk(89%).CONCLUSION Synchronous GC and GIST may not be rare.They have specific clinicopathological characteristics,and may have mutual inhibition in pathogenesis and progression.

Current clinical management of gastrointestinal stromal tumor

Gastrointestinal stromal tumors(GISTs) are the most common malignant subepithelial lesions(SELs) of the gastrointestinal tract. They originate from the interstitial cells of Cajal located within the muscle layer and are characterized by over-expression of the tyrosine kinase receptor KIT. Pathologically, diagnosis of a GIST relies on morphology and immunohistochemistry [KIT and/or discovered on gastrointestinal stromal tumor 1(DOG1) is generally positive]. The prognosis of this disease is associated with the tumor size and mitotic index. The standard treatment of a GIST without metastasis is surgical resection. A GIST with metastasis is usually only treated by tyrosine kinase inhibitors without radical cure; thus, early diagnosis is the only way to improve its prognosis. However, a GIST is usually detected as a SEL during endoscopy, and many benign and malignant conditions may manifest as SELs. Conventional endoscopic biopsy is difficult for tumors without ulceration. Most SELs have therefore been managed without a histological diagnosis. However, a favorable prognosis of a GIST is associated with early histological diagnosis and R0 resection. Endoscopic ultrasonography(EUS) and EUS-guided fine needle aspiration(EUSFNA) are critical for an accurate diagnosis of SELs. EUSFNA is safe and effective in enabling an early histological diagnosis and adequate treatment. This review outlines the current evidence for the diagnosis and management of GISTs, with an emphasis on early management of small SELs.

Rare adult gastric duplication cyst mimicking a gastrointestinal stromal tumor

Gastric duplication cyst is a very rare gastrointestinal tract malformation that accounts for 2%-4%of alimentary tract duplications.Most cases are diagnosed within the first year of life,following presentation of abdominal pain,vomiting,and weight loss and clinical discovery of an abdominal palpable mass.This case report describes a very uncommon symptomatic gastric duplication cyst diagnosed for the first time in adulthood.Only a few other case reports of similar condition exist,and all were identified by endosonography.The current case involves a 52-year-old male who presented with a onemonth history of progressive iron deficiency anemia without overt gastrointestinal bleeding.The patient underwent esophagogastroduodenoscopy,which revealed a 2.0 cm pinkish subepithelial lesion,suspected to be a gastrointestinal stromal tumor(GIST)and source of gastrointestinal bleeding.The endosonography showed inhomogeneous hypoechoic lesions with focal anechoic areas arising from a second and third layer of the gastric wall.Differential diagnoses of GIST,neuroendocrine tumor,or pancreatic heterotopia were made.The lesion was removed using an endoscopic submucosal resection technique.Histopathology revealed an erosive gastric mass composed of a complex structure of dilated gastric glands surrounded by fibro-muscular tissue,fibroblasts,and smooth muscle bundles,which led to the diagnosis of gastric duplication.

Gastrointestinal stromal tumor of the stomach:How to manage?

Gastrointestinal stromal tumor (GIST) is one of the most common malignant mesenchymal tumors of the stomach. Prognosis of this disease is related to tumor size and mitotic activity and early diagnosis is the only way to improve it.Diagnosis of GIST always requires histological and immunohistochemical confirmation as no imaging modalities can diagnose it conclusively.Endoscopic forceps biopsy results are frequently negative. Endoscopic ultrasound-guided fine needle asp- iration (EUS-FNA) is a technique which allows tissue samples to be obtained with minimal risks and is accurate in the diagnosis of GIST. From the point of view of the endoscopist, aggressive use of EUS-FNA is the only promising way to allow early diagnosis and early treatment of this disease.

How best to manage gastrointestinal stromal tumor

Gastrointestinal stromal tumors(GISTs) are rare but most common nonepithelial tumor of gastrointestinal tract. They are often found incidentally on computed tomography and endoscopic investigations. Increasing knowledge of the pathogenesis of GISTs and the advent of tyrosine kinase inhibitors revolutionized the management of GISTs. The newer advanced endoscopic techniques have challenged the conventional surgery although the true efficacy and safety of endoscopic approach is not clear at this time. This review article focuses on pathogenesis, diagnosis and management of GISTs.

Expression profile of microRNAs in gastrointestinal stromal tumors revealed by high throughput quantitative RT-PCR microarray

AIM: To investigate the microRNA(miRNA) expression profile in gastrointestinal stromal tumor(GIST) tissues that could serve as a novel diagnostic biomarker for GIST detection.METHODS: We performed a quantitative real-time quantitative reverse transcriptase polymerase chain reaction assay to analyze the expression of 1888 miRNAs in a sample set that included 54 GIST tissue samples.RESULTS: We found that dysregulation of several miRNAs may be related to the malignant potential of GISTs. Six of these miRNAs, hsa-let-7c, miR-218,miR-488#, miR-4683, miR-34c-5p and miR-4773, were selected as the final list of biomarkers to separate the malignant GISTs(M group) from the benign GISTs(B group). In addition, MiR-29b-2#, hsa-let-7c, miR-891 b, miR-218, miR-204, miR-204-3p, miR-628-5p,miR-744, miR-29c#, miR-625 and miR-196 a were used to distinguish between the borderline(BO group) and M groups. There were 11 common miRNAs selected to separate the benign and borderline(BB) group from the M group, including hsa-let-7c, miR-218, miR-628-5p,miR-204-3p, miR-204, miR-891 b, miR-488#, miR-145,miR-891 a, miR-34c-5p and miR-196 a.CONCLUSION: The identified miRNAs appear tobe novel biomarkers to distinguish malignant from benign GISTs, which may be helpful to understand the mechanisms of GIST oncogenesis and progression,and to further elucidate the characteristics of GIST subtypes.

Mucosal-incision assisted biopsy for suspected gastric gastrointestinal stromal tumors

To evaluate the diagnostic yield of the procedure, mucosal-incision assisted biopsy (MIAB), for the histological diagnosis of gastric gastrointestinal stromal tumor (GIST), we performed a retrospective review of the 27 patients with suspected gastric GIST who underwent MIAB in our hospitals. Tissue samples obtained by MIAB were sufficient to make a histological diagnosis (diagnostic MIAB) in 23 out of the 27 patients, where the lesions had intraluminal growth patterns. Alternatively, the samples were insufficient (non-diagnosticMIAB) in remaining 4 patients, three of whom had gastric submucosal tumor with extraluminal growth patterns. Although endoscopic ultrasound and fine needle aspiration is the gold standard for obtaining tissue specimens for histological and cytological analysis of suspected gastric GISTs, MIAB can be used as an alternative method for obtaining biopsy specimens of lesions with an intraluminal growth pattern.

Clinical course of suspected small gastrointestinal stromal tumors in the stomach

BACKGROUND Gastric subepithelial lesions are frequently encountered during endoscopic examinations,and the majority of them are small and asymptomatic.Among these lesions,gastrointestinal stromal tumors(GISTs)are the major concern for patients and clinicians owing to their malignant potentials.Although previous guidelines suggested periodic surveillance for such small(≤20 mm)lesions,several patients and clinicians have still requested or prescribed repeated examinations or radical resection,posing extra medical burdens and risks.AIM To describe the clinical course of suspected small gastric GISTs and provide further evidence for surveillance strategy for tumor therapy.METHODS This single-center,retrospective study was conducted at West China Hospital,Sichuan University.Consecutive patients with suspected small gastric GISTs were reviewed from November 2004 to November 2018.GIST was suspected according to endoscopic ultrasonography features:hypoechoic lesions from muscularis propria or muscularis mucosa.Eligible patients with suspected small(≤20 mm)GISTs were included for analysis.Patients’demographic data,lesions’characteristics,and follow-up medical records were collected.RESULTS A total of 383 patients(male/female,121/262;mean age,54 years)with 410 suspected small gastric GISTs(1 lesion in 362 patients,2 lesions in 16,3 lesions in4,and 4 lesions in 1)were included for analysis.The most common location was gastric fundus(56.6%),followed by body(29.0%),cardia(12.2%),and antrum(2.2%).After a median follow-up of 28 mo(interquartile range,16-48;range,3-156),402 lesions(98.0%)showed no changes in size,and size of 8 lesions(2.0%)was increased(mean increment,10 mm).Of the 8 lesions with size increment,endoscopic or surgical resection was performed in 6 patients(5 GISTs and 1 leiomyoma).For other 2 remaining patients,unroofing biopsy or endoscopic ultrasound-guided fine-needle aspiration was carried out(2 GISTs),while no further change in size was noted over a period of 62-64 mo.CONCLUSION The majority of suspected small(≤20 mm)gastric GISTs had no size increment during follow-up.Regular endoscopic follow-up without pathological diagnosis may be highly helpful for such small gastric subepithelial lesions.

Case report and review of the literature of primary gastrointestinal amyloidosis diagnosed with enteroscopy and endoscopic ultrasonography

Here, we report a rare case of primary gastrointestinal amyloidosis in a stable condition after being followed up for three years. The patient was admitted to the hospital in 2014. Tests showed decreased levels of hemoglobin and ferritin. Transoral and transanal enteroscopy showed multiple nodular protuberances in the esophagus, ileum, colon and rectum. Endoscopic ultrasonography indicated the nodular protuberances stemmed from the submucosa and partially invaded the intrinsic myometrium. Pathological examinations found multiple small nodules in the submucosa and dyed structures, which were positive for special Congo red dyeing. After treatment with oral iron supplements, the levels of hemoglobin and ferritin became normal. It is concluded that the patient represents a case of primary gastrointestinal amyloidosis with multiple nodular protuberances in the digestive tract with controllable moderate abdominal discomfort and anemia and a benign course. Enteroscopy and endoscopic ultrasonography play an important role in the diagnosis of primary gastrointestinal amyloidosis.

Primary gastrointestinal stromal tumor of the liver treated with sequential therapy

A 67-year-old female presented with a primary hepatic gastrointestinal stromal tumor that was detected by computed tomography and diagnosed based on histopathological and genetic analyses.The tumor was microscopically composed of spindle cells and epithelioid cells,and immunohistochemistry results showed positive staining for CD117 and CD34expression.A genetic analysis revealed a heterozygous point mutation and deletion in exon 11 of c-KIT.After an R0 resection,imatinib mesylate was administered for 1 year until its use was discontinued due to severe side effects.Two years after the original operation,the tumor recurred in the residual liver and was completely resected again.Imatinib mesylate was administered for 2 years until it was replaced by sunitinib malate because of disease progression.The patient has survived for 53 mo after undergoing a sequential therapy consisting of surgical excision,imatinib and sunitinib.