Gastrointestinal stromal tumors: a clinicopathological and immunohistochemical study of 121 cases

Using machine learning models to predict synchronous genitourinary cancers among gastrointestinal stromal tumor patients

Objectives

Gastrointestinal stromal tumors (GISTs) can occur synchronously with other neoplasms, including the genitourinary (GU) system. Machine learning (ML) may be a valuable tool in predicting synchronous GU tumors in GIST patients, and thus improving prognosis. This study aims to evaluate the use of ML algorithms to predict synchronous GU tumors among GIST patients in a specialist research center in Saudi Arabia.

Materials and Methods

We analyzed data from all patients with histopathologically confirmed GIST at our facility from 2003 to 2020. Patient files were reviewed for the presence of renal cell carcinoma, adrenal tumors, or other GU cancers. Three supervised ML algorithms were used: logistic regression, XGBoost Regressor, and random forests (RFs). A set of variables, including independent attributes, was entered into the models.

Results

A total of 170 patients were included in the study, with 58.8% (n = 100) being male. The median age was 57 (range: 9-91) years. The majority of GISTs were gastric (60%, n = 102) with a spindle cell histology. The most common stage at diagnosis was T2 (27.6%, n = 47) and N0 (20%, n = 34). Six patients (3.5%) had synchronous GU tumors. The RF model achieved the highest accuracy with 97.1%.

Conclusion

Our study suggests that the RF model is an effective tool for predicting synchronous GU tumors in GIST patients. Larger multicenter studies, utilizing more powerful algorithms such as deep learning and other artificial intelligence subsets, are necessary to further refine and improve these predictions.

Clinicopathological and immunohistochemical characterization of gastrointestinal stromal tumour at four tertiary health centers in Nigeria using CD117, DOG1, and human epidermal growth factor receptor-2 biomarkers

Aims

Gastrointestinal stromal tumors (GISTs) are neoplastic lesions that primarily affect the digestive tract and develop from interstitial cells of Cajal. These lesions require histopathological and immunohistochemical characterization due to their malignant potential and personalized treatment. In this investigation, the sex, age, lesional sites of origin, histopathological types, the prevalence of human epidermal growth factor receptors (HER-2) expression, prognostic indices (based on tumor size and mitotic figures), expression of CD117 and DOG1, and characteristics of patients with GIST were all characterized.

Materials and Methods

This was a retrospective cross-sectional analysis of GIST cases seen at four tertiary health-care centers in Nigeria over a 10-year period (2008-2017) and investigated utilizing histopathological and immunohistochemical (CD117, DOG1, and HER-2) methods.

Results

In this investigation, there were twenty GIST cases. Notably, the majority (40%) of the cases had tumors with sizes between 7.0 and 8.0 cm; the stomach was the most frequent site (70%) and the spindle cell type of GIST was the most prevalent (80%) histopathological type. In addition, the stomach was significantly associated with GIST as an origin site (with a P = 0.001), and 100% and 50% of these tumors were immunoreactive with CD117 and DOG1, respectively.

Conclusions

In our study, GISTs most frequently develop in the stomach, and CD117 and DOG1 are essential for correctly diagnosing these tumors. However, HER-2 immunoreactivity is a predictive marker of survival for personalized care.

Value of enhanced computed tomography in differentiating small mesenchymal tumours of the gastrointestinal from smooth muscle tumours

BACKGROUND

Computed tomography (CT) technology has been gradually used in the differentiation of small mesenchymal tumors of the stomach and intestines from smooth muscle tumours.

AIM

To explore the value of enhanced CT in the differentiation of small mesenchymal tumors of the stomach and intestines from smooth muscle tumours.

METHODS

Clinical data of patients with gastric mesenchymal or gastric smooth muscle tumours who were treated in our hospital from May 2018 to April 2023 were retrospectively analysed. Patients were divided into the gastric mesenchymal tumor group and the gastric smooth muscle tumor group respectively (n = 50 cases per group). Clinical data of 50 healthy volunteers who received physical examinations in our hospital during the same period were selected and included in the control group. Serum levels of carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), carbohydrate antigen 19-9 (CA19-9), CA-125 and cytokeratin 19 fragment antigen 21-1 were compared among the three groups. The value of CEA and CA19-9 in the identification of gastric mesenchymal tumours was analysed using the receiver operating characteristic (ROC) curve. The Kappa statistic was used to analyse the consistency of the combined CEA and CA19-9 test in identifying gastric mesenchymal tumours.

RESULTS

CEA levels varied among the three groups in the following order: The gastric mesenchymal tumour group > the control group > the gastric smooth muscle tumour group. CA19-9 levels varied among the three groups in the following order: The gastric mesenchymal group > the gastric smooth muscle group > the control group, the difference was statistically significant (P < 0.05). ROC analysis showed that the area under the curve of CEA and CA19-9 was 0. 879 and 0. 782, respectively.

CONCLUSION

Enhanced CT has shown value in differentiating small mesenchymal tumors of the stomach and intestines from smooth muscle tumors.

Three cases of jejunal tumors detected by standard upper gastrointestinal endoscopy: A case series

BACKGROUND

In patients with obscure gastrointestinal bleeding, re-examination with standard upper endoscopes by experienced physicians will identify culprit lesions in a substantial proportion of patients. A common practice is to insert an adult-sized forward-viewing endoscope into the second part of the duodenum. When the endoscope tip enters after the papilla, which is a marker for the descending part of the duodenum, it is difficult to endoscopically judge how far the duodenum has been traversed beyond the second part.

CASE SUMMARY

We experienced three cases of proximal jejunal masses that were diagnosed by standard upper gastrointestinal endoscopy and confirmed with surgery. The patients visited the hospital with a history of melena; during the initial upper gastrointestinal endoscopy and colonoscopy, the bleeding site was not confirmed. Upper gastrointestinal bleeding was suspected; thus, according to guidelines, upper endoscopy was performed again. A hemorrhagic mass was discovered in the small intestine. The lesion of the first patient was thought to be located in the duodenum when considering the general insertion depth of a typical upper gastrointestinal endoscope; however, during surgery, it was confirmed that it was in the jejunum. After the first case, lesions in the second and third patients were detected at the jejunum by inserting the standard upper endoscope as deep as possible.

CONCLUSION

The deep insertion of standard endoscopes is useful for the diagnosis of obscure gastrointestinal bleeding.

Analysis of C-Kit Exon 9, Exon 11 and BRAFV600E Mutations Using Sangers Sequencing in Gastrointestinal Stromal Tumours

Background

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal neoplasms in the gastrointestinal (GI) tract. The mutation of C-KIT is considered to be the crucial step in the tumorigenesis. Targeted therapies are being developed focusing these mutations. Various exon mutations of GIST responded in varied patterns to this targeted therapy. This study was carried out to evaluate the C-KIT exon 11, exon 9 and BRAF V600E mutations among GIST specimens.

Methods

This retrospective study was carried out among 20 DNA extracted specimens from paraffin blocks of GIST received in our tertiary teaching institution for a period of three years. DNA sequencing was carried out for mutational analyses on C-KIT exon 9, C-KIT exon 11 and BRAF V600E genes using Sanger sequencing.

Results

Histologically, majority of the tumors had spindle cell morphology. About 19 cases were positive for CD117. The analysis of type of mutations showed that three cases carried Exon 11 and three cases carried Exon 9 mutations. BRAF V600E mutation was seen in one case.

Conclusion

It is essential to conduct molecular studies on GISTs in order to get a clear understanding of the pathogenesis and behavior pattern. This will also help in designing targeted therapies and assessing recurrence. With the advent of rapidly evolving personalized therapy, the evaluation of genetic mutations is essential for diagnosis and prognostic value.

Lower GI Bleeding: An Update on Incidences and Causes

Bleeding from the lower gastrointestinal tract represents a significant source of morbidity and mortality. The colon represents the vast majority of the location of bleeding with only a much smaller incidence occurring in the small intestine. The major causes of lower gastrointestinal bleeding (LGIB) are from diverticulosis, vascular malformations, and cancer. We discuss the incidence and causes of LGIB.

Gastrointestinal stromal tumor: clinicopathological characteristics and pathologic prognostic analysis

Objective

This study aimed to understand clinicopathological characteristics of gastrointestinal stromal tumors (GISTs) and correlation between pathologic features and clinical outcome.

Methods

We used 76 cases diagnosed as primary GISTs during January 2007 to July 2017 at Army Institute of Pathology, Thailand. Clinical, survival, and pathological data were collected and analyzed.

Results

Ages of the patients ranged from 15 to 88 years (M:F = 1:1). The most common presentation was gastrointestinal bleeding (39.7%). The most common site was the stomach (64.5%). Tumor size ranged from 0.6 to 25.5 cm (average 8.78 cm). Histologic types were spindle cell type (75%), mixed spindled-epithelioid type (17.1%), and epithelioid type (7.9%). The majority of histologic subtype was diffuse hypercellularity (67.1%). Tumor necrosis was found in 38.1% and 80% showed low mitotic counts. Most gastrointestinal stromal tumors (27.6%) are low-risk category according to Miettinen and Lasota’s algorithm. Metastasis was found in 27.7%, mostly occurs within 2 years, and is correlated with tumor size > 10 cm (P = 0.023), non-spindle cell histologic type (P = 0.027), mitotic count > 5/5mm² (P = 0.000), myxoid change (P = 0.011), and mucosal invasion (P = 0.002). Recurrence was found in 8.1%, mostly occurs within 7 years, and correlated with myxoid change (P = 0.045).

Conclusion

We found that most of GISTs show spindle cell type and low-risk category. Metastasis was correlated with tumor size > 10 cm, non-spindle cell histologic type, mitotic count > 5/5mm², myxoid change, and mucosal invasion. Recurrence was correlated with myxoid change.

GIST Manifesting as a Retroperitoneal Tumor: Clinicopathologic Immunohistochemical, and Molecular Genetic Study of 112 Cases

Most gastrointestinal stromal tumors (GISTs) occur in the tubular gastrointestinal (GI) tract, but some present apparently outside the GI tract. In this study, we analyzed 112 GISTs located in the retroperitoneum. These tumors occurred in 55 women and 57 men with a median age of 65 years (range: 21 to 89 y). On the basis of clinically or histologically detected connections to GI tract, 15 tumors were considered likely of gastric, 9 duodenal, and 13 of small intestinal origin. The remaining cases were categorized by location as peripancreatic (n=25), pelvic (n=11), mesenteric (n=4), and of unspecified/miscellaneous sites (n=35). The tumors varied in size 3 to 35 cm (median, 15 cm) and by mitotic rate per 5 mm, 0 to >100 (median, 10). Histologically the tumors apparently arising outside the GI tract had features of intestinal (n=41) and gastric GISTs (n=25); 9 cases had indeterminate histology. The histologic variants included spindled, epithelioid, vacuolated, nested, and myxoid potentially simulating other tumors such as liposarcoma and solitary fibrous tumor. Most GISTs were KIT-positive (106/112 cases), and the remaining 6 tumors were DOG1/Ano1-positive. Five cases showed focal nuclear positivity for MDM2. KIT mutations were detected in 42/59 cases, and PDGFRA mutations in 4/16 KIT wild-type and 3/5 of the KIT-negative tumors analyzed. One pelvic retroperitoneal GIST was succinate dehydrogenase deficient. All 79 patients were dead at last follow-up with a median survival of 14 months, with few survivals >5 years. Only operable versus inoperable tumor was a statistically favorable factor in univariate analysis (P<0.01). In multivariate analysis, mitotic rate >50/5 mm was significant for a shorter survival (hazard ratio, 5.25; 95% confidence interval, 1.65-16.8; P<0.01). Histologic and clinicopathologic similarity of extragastrointestinal retroperitoneal GISTs with GISTs of GI tract suggests their GI tract origin. Potentially overlapping features between GIST and other retroperitoneal tumors necessitate use of multiple diagnostic markers and molecular genetic studies.

Small bowel bleeding: a comprehensive review

The small intestine is an uncommon site of gastro-intestinal (GI) bleeding; however it is the commonest cause of obscure GI bleeding. It may require multiple blood transfusions, diagnostic procedures and repeated hospitalizations. Angiodysplasia is the commonest cause of obscure GI bleeding, particularly in the elderly. Inflammatory lesions and tumours are the usual causes of small intestinal bleeding in younger patients. Capsule endoscopy and deep enteroscopy have improved our ability to investigate small bowel bleeds. Deep enteroscopy has also an added advantage of therapeutic potential. Computed tomography is helpful in identifying extra-intestinal lesions. In cases of difficult diagnosis, surgery and intra-operative enteroscopy can help with diagnosis and management. The treatment is dependent upon the aetiology of the bleed. An overt bleed requires aggressive resuscitation and immediate localisation of the lesion for institution of appropriate therapy. Small bowel bleeding can be managed by conservative, radiological, pharmacological, endoscopic and surgical methods, depending upon indications, expertise and availability. Some patients, especially those with multiple vascular lesions, can re-bleed even after appropriate treatment and pose difficult challenge to the treating physician.

Differential clinical and pathological characteristics of esophageal stromal tumors and leiomyomata

The objective of the study was to assess the differences in clinical and pathological characteristics between esophageal stromal tumor and leiomyoma. Data from 93 esophageal stromal tumors and leiomyomata cases were retrospectively analyzed, including clinical symptoms, endoscopic features, pathological characteristics, immunohistochemistry (IHC), and treatment. All cases underwent endoscopic ultrasonography examination before treatment. Lesions arising from the muscularis mucosa were resected by endoscopic mucosal resection or endoscopic submucosal dissection. Lesions arising from the muscularis propria were resected by surgery. All specimens were examined by IHC. Patients were followed up after endoscopic mucosal resection or endoscopic submucosal dissection. No difference was observed in clinical symptoms and endoscopic features between the two groups. Endoscopic ultrasonography demonstrated all lesions to be hypoechoic and well circumscribed. Most lesions >2 cm had heterogeneous internal ultrasound signal. In esophageal stromal tumor, 100% (29/29) were CD117-positive and DOG-1-positive; 72.4% (21/29) and 51.7% (15/29) were CD34-positive and smooth muscle actin-positive, respectively. In esophageal leiomyomata, 100% (64/64) were smooth muscle actin-positive and desmin-positive; 100% were CD117-negative and DOG-1-negative. No local recurrence was detected in followed up patients (n = 49) after an average of 1.8 years (1.0-3.0 years). IHC analyses are important for distinguishing esophageal stromal tumor from leiomyoma. Early endoscopic resection is an effective treatment option for esophageal stromal tumors >1 cm.

[Case of primary retroperitoneal GIST (gastrointestinal stromal tumor) with rapid progression]

A 69-year-old man complaining of left abdominal pain was referred from a private clinic for retroperitoneal masses that were discovered on abdominal ultrasound in November 2010. CT scan showed retroperitoneal masses, located above the left kidney, measuring 10 cm. Para-aortic lymph nodes were swelling. We performed open biopsy to make the diagnosis in December 2010. The diagnosis was primary retroperitoneal GIST (gastrointestinal stromal tumor). We started imatinib 400 mg/day according to the Japan GIST guideline in January 2011. However the tumor pogressed rapidly, after 1 month the patient died.

Cytomorphology of gastrointestinal stromal tumors and extra-gastrointestinal stromal tumors: A comprehensive morphologic study

BACKGROUND

The term gastrointestinal stromal tumors (GIST) is used to refer to those mesenchymal neoplasms of the gastrointestinal tract (GIT) which express CD117, a c-kit proto-oncogene protein.

AIMS

To study the cytological features of GIST and extra-gastrointestinal stromal tumors (EGIST), to correlate them with histology and to determine cytological indicators of malignancy.

MATERIALS AND METHODS

Cytological smears from patients diagnosed as GIST/EGIST on histology were retrieved. From Jan 2000 to July 2010, 26 GIST (13 primary, 12 metastatic, one recurrent) and seven EGIST (5 primary, one metastatic, one recurrent) cytologic samples from 27 patients were identified.

RESULTS

The patients included 20 males and 7 females with a mean age of 50.6 years. Tumor sites included stomach (5), duodenum (5), ileum (2), ileocecal (1), rectum (1), liver (9), retroperitoneum (5), mesentery (1), subcutaneous nodule (1), supra-penile lump (1), ascitic (1) and pleural fluids (1). The smears were cellular with cohesive to loosely cohesive thinly spread irregularly outlined cell clusters held together by thin calibre vessels. The tumor cells were mild to moderately pleomorphic, spindle to epithelioid with variable chromatin pattern and variable cytoplasm. Cellular dyscohesion, nuclear pleomorphism, intranuclear pseudoinclusions, prominent nucleoli, mitosis and necrosis were more prominent in malignant, metastatic and recurrent tumors.

CONCLUSIONS

GISTs show a wide spectrum of cytological features and the presence of mitosis, necrosis and nuclear pleomorphism can help in prediction of malignant behavior. Further, cytology is a very useful screening modality in patients of GIST and EGIST to detect early recurrence and metastasis at follow-up.

Contribution of DOG1 expression to the diagnosis of gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract, and the majority contain KIT or PDGFRA-activating mutations. However, up to 10% of GISTs are c-kit-negative. Antibodies with increased sensitivity and specificity for the detection of c-kit-negative GIST cases may be of value, especially because some of these cases may also benefit from tyrosine kinase inhibitor therapy. Hematoxylin and Eosin sections of 33 GISTs were re-examined in order to define histopathological criteria used in risk assessment of these tumors. Immunohistochemistry with a panel of antibodies [c-kit, DOG1 (discovered on GIST 1), CD34, smooth muscle actin (SMA), Desmin, S100 and Ki67] was performed on 5μm-thick paraffin sections of all tumors. Statistical analysis of immunohistochemical studies showed that DOG1 and CD117 were the most sensitive and specific antibodies in the diagnosis of GISTs. Other antibodies were unhelpful in confirming a diagnosis of GIST, but were particularly useful in the differential diagnosis. Reactivity for DOG1 may aid in the diagnosis of GISTs, which fail to express c-kit antigen, and lead to appropriate treatment with imatinib mesylate, an inhibitor of the KIT tyrosine kinase.

Clinicopathological study of 113 gastrointestinal stromal tumors

BACKGROUND

Gastrointestinal stromal tumor (GIST) is the most common sarcoma of the gastrointestinal tract. A retrospective study was done to evaluate the clinical and pathological features and the effect of adjuvant treatment with imatinib.

METHOD

The case records of 113 GIST patients were retrospectively reviewed and the clinicopathological features, treatments, and outcomes were recorded.

RESULTS

There were 82 males and 31 females, with a median age of 51 years. All patients were symptomatic (mean duration 4 months) and abdominal pain was the most common symptom. The primary sites of GIST were small intestine (38), stomach (36), and others (39). The tumor diameter on imaging varied from 1 to 26 (mean 10.9) cm. Thirty percent of patients presented with metastasis. There was no association between tumor size and presence of metastasis (p = 0.9). Most common histology was spindle cell morphology followed by mixed spindle cell and epithelioid morphology. Seventy percent patients had high risk (HR) category as per Fletcher risk score. Fifty-three percent had curative resection, after which 34 % had adjuvant imatinib therapy. Recurrence rates were significantly lower in patients receiving adjuvant imatinib therapy (p = 0.003). No statistically significant association was noted between HR Fletcher score, Mib score >10, tumor size >10 cm, and the risk of recurrence (p = 0.29, 0.07, and 0.87, respectively). Liver was the most common site of metastasis. Side effects were tolerable and edema and fluid retention were the commonest.

CONCLUSION

Sites of GIST in Indian patients were different from those in western studies. Adjuvant imatinib therapy significantly reduced the risk of recurrence.

Cystically degenerated leiomyoma of the rectosigmoid managed laparoscopically at 13 weeks of gestation

The safety of laparoscopic management of adnexal masses in pregnancy has been documented. Herein we report laparoscopic removal during pregnancy of a cystically degenerated leiomyoma of the sigmoid colon, which had been mistaken for an adnexal mass. When smooth muscle gastrointestinal tumors are observed, it is important that they be characterized with appropriate markers so that postoperative treatment can be individualized to the patient.

Endoscopic therapy for gastric stromal tumors originating from the muscularis propria

AIM: To explore endoscopic therapy methods for gastric stromal tumors originating from the muscularis propria.

METHODS: For 69 cases diagnosed as gastric stromal tumors originating from the muscularis propria, three types of endoscopic therapy were selected, based on the size of the tumor. These methods included endoscopic ligation and resection (ELR), endoscopic submucosal excavation (ESE) and endoscopic full-thickness resection (EFR). The wound surface and the perforation of the gastric wall were closed with metal clips. Immunohistostaining for CD34, CD117, Dog-1, S-100 and smooth muscle actin (SMA) was performed on the resected tumors.

RESULTS: A total of 38 cases in which the tumor size was less than 1.2 cm were treated with ELR; three cases were complicated by perforation, and the perforations were closed with metal clips. Additionally, 18 cases in which the tumor size was more than 1.5 cm were treated with ESE, and no perforation occurred. Finally, 13 cases in which the tumor size was more than 2.0 cm were treated with EFR; all of the cases were complicated by artificial perforation, and all of the perforations were closed with metal clips. All of the 69 cases recovered with medical treatment, and none required surgical operation. Immunohistostaining demonstrated that among all of the 69 gastric stromal tumors diagnosed by gastroscopy, 12 cases were gastric leiomyomas (SMA-positive), and the other 57 cases were gastric stromal tumors.

CONCLUSION: Gastric stromal tumors originating from the muscularis propria can be treated successfully with endoscopic techniques, which could replace certain surgical operations and should be considered for further application.

Primary Extra-gastrointestinal Stromal Tumor of Retroperitoneum

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. More rarely neoplasms with histology and immunohistochemistry similar to GISTs may occur outside the gastrointestinal tract ( omentum, mesentery and retroperitoneum) and are so-called Extra-gastrointestinal Stromal Tumors (EGISTs). EGISTs arising in the retroperitoneum are extremely rare: to date, only 58 cases have been reported in the literature.

CASE REPORT

We herein report a case of a primary EGIST of the retroperitoneum surgically treated. The pre-operative radiological evaluation showed a retroperitoneal mass, placed in left paravertebral region.

RESULTS

Morphological and immunohistochemical features led to a diagnosis of extra-gastrointestinal stromal tumor (intermediate-low risk form).

CONCLUSIONS

As a result of the rarity of reports of primary EGISTs of retroperitoneum we need to analyze the data of reported cases in order to gain a better understanding about the pathogenesis, prognosis and optimal treatment of this disease.

Epidemiology of cancer of the small intestine

Cancer of the small intestine is very uncommon. There are 4 main histological subtypes: adenocarcinomas, carcinoid tumors, lymphoma and sarcoma. The incidence of small intestine cancer has increased over the past several decades with a four-fold increase for carcinoid tumors, less dramatic rises for adenocarcinoma and lymphoma and stable sarcoma rates. Very little is known about its etiology. An increased risk has been noted for individuals with Crohn’s disease, celiac disease, adenoma, familial adenomatous polyposis and Peutz-Jeghers syndrome. Several behavioral risk factors including consumption of red or smoked meat, saturated fat, obesity and smoking have been suggested. The prognosis for carcinomas of the small intestine cancer is poor (5 years relative survival < 30%), better for lymphomas and sarcomas, and best for carcinoid tumors. There has been no significant change in long-term survival rates for any of the 4 histological subtypes. Currently, with the possible exceptions of obesity and cigarette smoking, there are no established modifiable risk factors which might provide the foundation for a prevention program aimed at reducing the incidence and mortality of cancers of the small intestine. More research with better quality and sufficient statistical power is needed to get better understanding of the etiology and biology of this cancer. In addition, more studies should be done to assess not only exposures of interest, but also host susceptibility.