Gastrointestinal stromal tumors: the histology report

Robot-assisted resection of oesophageal leiomyoma: a single-centre retrospective analysis of 57 cases

BACKGROUNDS

Oesophageal leiomyoma is the most common benign tumour of the oesophagus, and complete tumour enucleation is the preferred treatment. The aim of this study is to evaluate the clinical application and technical advantages of Robotic-assisted Thoracoscopic Surgery (RATS) during the resection of oesophageal leiomyoma.

METHODS

A retrospective study was conducted on patients who underwent robotic surgery for oesophageal diseases at our hospital from September 2017 to December 2023. Demographic statistics and clinical pathological characteristics, intraoperative and postoperative outcomes, immune histopathological staining, tumour pathology diagnosis and follow-up were analyzed.

RESULTS

A total of 57 patients were enrolled in the study, including 42 males and 15 females with an average age of 49 years All patients received surgical treatment, with 54 patients undergoing robot-assisted resection of oesophageal tumour, one patient undergoing conversion to thoracotomy, and two patients undergoing exploratory surgery. The mean surgical time was 130 minutes, and the mean blood loss was 50 mL. Of the 55 patients who underwent tumour resection, 54 were pathologically diagnosed as oesophageal leiomyoma and one as atypical leiomyoma. Only one patient developed pulmonary infection after surgery, and there was no perioperative mortality. The average postoperative hospital stay was 9 days. All patients were followed up for a median time of 16 months (range: 1 to 70 months), and there was no recurrence or long-term complications after surgery.

CONCLUSION

Robot-assisted resection of oesophageal leiomyoma is safe and feasible, and can provide ideal short-and medium-term results.

C-kit-negative transmural gastrointestinal stromal tumor in the stomach: A rare case of upper GI bleeding in Ghana

Upper GI bleeding from GIST is rare in Africa. The C-kit-negative variant is uncommon worldwide. We report a case of a 42-year-old woman managed for upper GI bleeding secondary to stomach GIST, negative for CD117 but positive for DOG 1 and CD 34. The 1-year postsurgery review is uneventful.

Gastrointestinal stromal tumors: A multidisciplinary challenge

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors located in the alimentary tract. Its usual manifestation is gastrointestinal bleeding. However, small asymptomatic lesions are frequently detected as incidental finding. Characteristically, most GISTs (> 95%) are positive for the KIT protein (CD117) by IHC staining and approximately 80%-90% of GISTs carry a mutation in the c-KIT or PDGFRA genes. Mutational analysis should be performed when planning adjuvant and neoadjuvant therapy, due to its possible resistance to conventional treatment. The arise of tyrosine kinase inhibitor has supposed a revolution in GISTs treatment being useful as adjuvant, neoadjuvant or recurrence disease treatment. That is why a multidisciplinary approach to this disease is required. The correct characterization of the tumor at diagnosis (the diagnosis of recurrences and the evaluation of the response to treatment with tyrosine kinase inhibitors) is fundamental for facing these tumors and requires specialized Endoscopist, Radiologists and Nuclear Medicine Physician. Surgery is the only potentially curative treatment for suspected resectable GIST. In the case of high risk GISTs, surgery plus adjuvant Imatinib-Mesylate for 3 years is the standard treatment. Neoadjuvant imatinib-mesylate should be considered to shrink the tumor in case of locally advanced primary or recurrence disease, unresectable or potentially resectable metastasic tumors, and potentially resectable disease in complex anatomic locations to decrease the related morbidity. In the case of Metastatic GIST under Neoadjuvant treatment, when there are complete response, stable disease or limited disease progression, complete cytoreductive surgery could be a therapeutic option if feasible.

Gastrointestinal stromal tumor of the esophagus: current issues of diagnosis, surgery and drug therapy

Gastrointestinal stromal tumors (GISTs) often arise in the stomach and small intestine, while esophageal GISTs are rare. Due to their rarity, clinicopathological data on esophageal GISTs are extremely limited, and this results in a lack of clear recommendations concerning optimal surgical management for esophageal GISTs. It is difficult to distinguish esophageal GIST from leiomyoma, the most frequent esophageal mesenchymal tumor, prior to resection, because the two types of tumors appear similar on computed tomography (CT), endoscopic ultrasound (EUS), and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET). Fine-needle aspiration biopsy (FNAB) under EUS enables definitive diagnosis, but it is often avoided because scarring could make enucleation more difficult and increase the risk of tumor dissemination by capsule destruction. Esophageal segmental and wedge resections are not usually performed due to the anatomical peculiarity of the esophagus, and the surgical options are limited to the highly invasive esophagectomy or the much less invasive surgical tumor enucleation. The decision as to which surgical procedure should be performed for esophageal GISTs is still under debate. Tumor enucleation may be permitted for smaller tumors, and esophagectomy may be recommended for larger GISTs or high-risk tumors with a high mitotic rate. The purpose of neoadjuvant imatinib administration is downsizing of the GIST to reduce the extent of resection and to reduce the risk of intraoperative complications, including tumor rupture. The efficacy of neoadjuvant/adjuvant imatinib therapy for esophageal GISTs is poorly understood, because the reports are limited to case reports or case series with small numbers. More clinicopathological data and clinical trials for esophageal GIST are expected.

[Clinical and morphological characteristics of gastrointestinal stromal tumors]

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Despite this, GISTS comprise about 2% in the structure of digestive tract cancers. They are usually localized in the stomach; however, they can be found in the small intestine and more rarely in the colon and esophagus. Although approximately 70% of the GISTs consist predominantly of spindle cells; the epithelioid cell tumors represent 20% of cases; there are also mixed variants. This variability in the morphological structure of GISTs complicates their diagnosis.

Cytohistological and immunohistochemical characteristics of spindle-shaped mesenchymal neoplasms occurring in the gastrointestinal tract

The purpose of the present review is to analyze the cytohistological and immunohistochemical characteristics of spindle-shaped mesenchymal gastrointestinal neoplams (MGNs), a group of unusual neoplastic conditions with different biological behavior. These tumors exhibit clinical pictures strictly related to the site of origin and dimensions, even if they appear generally with an intramural localization. This latter point may suggest an useful application of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), mainly followed by the cell-block procedure (CBP) in the differential diagnostic approach. First of all, we discuss the most common entity of MGNs represented by gastrointestinal stromal tumors (GISTs), analyzing the morphologic characteristics and stressing the strength of immunohistochemical algorithm for diagnostic purposes. Successively, we have reported the less common group of spindle-shaped MGNs comprehensive of those arising elsewhere the soft tissues, such as leiomyomas, leiomyosarcomas, schwannomas, inflammatory myofibroblastic tumor and intra-abdominal desmoid fibromatosis. Finally, very uncommon spindle-shaped MGNs, like clear cell, follicular dendritic cell, undifferentiated pleomorphic and radiation-induced sarcomas as well as spindle cell dedifferentiated liposarcomas, have been briefly mentioned.

miRNA profiling in gastrointestinal stromal tumors: implication as diagnostic and prognostic markers

MicroRNAs are a class of short noncoding RNAs, that play a relevant role in multiple biological processes, such as differentiation, proliferation and apoptosis. Gastrointestinal stromal tumors (GIST) are considered as a paradigm of molecular biology in solid tumors worldwide, and after the discovery of specific alterations in the KIT and PDGFRA genes, they have emerged from anonymity to become a model for targeted therapy. Epigenetics have an emerging and relevant role in different steps of GIST biology such as tumorigenesis, disease progression, prognosis and drug resistance. The aim of the present review was to summarize the current evidence about the role of microRNAs in GIST, including their potential application as well as their limits.

Clinicopathologic analysis of gastrointestinal stromal tumors in duodenum and small intestine

BACKGROUND

The prognosis about duodenal GISTs is debatable. The purpose of this study is to compare the characteristics and the prognostic factors in patients with gastrointestinal stromal tumor (GIST) located in the duodenum with those located in the small intestine.

METHODS

One hundred-one patients with GIST located in the duodenum (n = 40), or small intestine (n = 61) underwent resection between 1996 and 2010. We analyzed clinicopathologic features, surgical outcomes, and prognostic factors.

RESULTS

Five-year survival rate in patients with GIST located in the duodenum and small intestine were 66.6 and 80.8%, respectively (p = 0.018). After survival analysis, high mitotic count and tumor rupture were identified as independent adverse prognostic factors. Advanced T stage and absence of adjuvant imatinib treatment were adverse prognostic factors with marginal statistical significance. The rate of progressive disease was significantly higher in patients with duodenal GISTs (36.8%) than in those with small intestinal GIST (29.6%) (p = 0.024).

CONCLUSIONS

The clinicopathologic findings of duodenal GIST differ from those of small intestinal GIST. Patients with duodenal GIST have a worse prognosis than those with small intestinal GIST. Aggressive treatment including surgical resection should be considered for duodenal GIST, even if the risk is relatively low.

Pancreaticoduodenectomy versus local resection in the treatment of gastrointestinal stromal tumors of the duodenum

Background

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms. However, duodenal GISTs compromise a small and rare subset and few studies have focused on them. We evaluated the surgical management of patients with duodenal GISTs treated by pancreaticoduodenectomy (PD) versus local resection (LR) in our institution and analyzed the postoperative outcomes.

Methods

This was a retrospective review of patients with duodenal GISTs managed in our institution from January 2006 to January 2012. Clinicopathologic findings and disease-free survival (DFS) of duodenal GIST patients were analyzed.

Results

A total of 48 patients were selected. The most common presentation was bleeding (60.4%), and the second portion of the duodenum (35.4%) was the most common dominant site. Of the patients, 34 (70.8%) underwent LR while 14 (29.2%) underwent PD. The surgical margins for all studied patients were free. Patients who ultimately underwent PD were more likely to present with a larger tumor (median size: PD, 6.3 cm vs LR, 4.0 cm; P = 0.02) and more commonly presented with a tumor in the second portion of the duodenum (second portion: PD, 64.3% vs LR, 23.5%; P = 0.007). The tumors treated by PD had a higher grade of risk compared with LR as defined by National Institutes of Health (NIH) criteria (P = 0.019). PD was significantly associated with a longer operation time and a longer hospital stay compared to LR (P < 0.001 and P = 0.001, respectively). In our study, the median follow-up period was 36 months (range: 0 to 81 months). The 1- and 3-year DFS was 100% and 88%, respectively. From multivariable analysis, the only significant factor associated with a worse DFS was an NIH high risk classification (hazard ratio = 4.24).

Conclusions

The recurrence of duodenal GIST was correlated to tumor biology rather than type of operation. PD was associated with a longer hospital stay and longer operation time. Therefore, LR with clear surgical margins should be considered a reliable and curative option for duodenal GIST and PD should be reserved for lesions not amenable to LR.

KIT gene mutation analysis in solid tumours: biology, clincial applications and trends in diagnostic reporting

Gain-of-function mutations involving c-kit protein, a cell-surface transmembrane receptor for stem cell factor, have been identified as a key oncogenic driver in a variety of solid tumours. Coupled with the development of tyrosine kinase inhibitors such as imatinib, c-kit has emerged as a viable drug target in what seems to be a validated therapeutic concept. This review will focus on gastrointestinal stromal tumours and melanomas, two types of solid tumours most closely associated with KIT gene mutations. The biology of KIT mutations in both conditions, as well as the value of KIT mutation testing in predicting disease and treatment outcomes are discussed. Since initial response to imatinib is largely influenced by mutation status, genotyping these tumours serves to facilitate personalised oncology. We also summarise our experience with diagnostic reporting of KIT mutation analysis over a period of 3 years, and briefly survey future developments in treatment, which indeed look very promising.

Primary gastrointestinal stromal tumor of the liver: report of a case

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. They can occur anywhere in the gastrointestinal tract, and rarely outside the digestive tract. We herein report a case of primary gastrointestinal stromal tumor that was resected from the liver of a 56-year-old male, which is the sixth description of a primary hepatic gastrointestinal stromal tumor. The tumor was shown to be completely limited within the liver by radiological, intraoperative and pathological examinations. The pathological results demonstrated an intermediate risk gastrointestinal stromal tumor, and immunohistochemical expression of CD117 was positive. Although rare, we suggested that GISTs should be considered in the differential diagnosis of hepatic nodules, and that not all hepatic gastrointestinal stromal tumors should automatically be considered to be metastases from a primary gastrointestinal site.

SDHA mutations in adult and pediatric wild-type gastrointestinal stromal tumors

Most gastrointestinal stromal tumors (GISTs) harbor oncogenic mutations in KIT or platelet-derived growth factor receptor-α. However, a small subset of GISTs lacks such mutations and is termed 'wild-type GISTs'. Germline mutation in any of the subunits of succinate dehydrogenase (SDH) predisposes individuals to hereditary paragangliomas and pheochromocytomas. However, germline mutations of the genes encoding SDH subunits A, B, C or D (SDHA, SDHB, SDHC or SDHD; collectively SDHx) are also identified in GISTs. SDHA and SDHB immunohistochemistry are reliable techniques to identify pheochromocytomas and paragangliomas with mutations in SDHA, SDHB, SDHC and SDHD. In this study, we investigated if SDHA immunohistochemistry could also identify SDHA-mutated GISTs. Twenty-four adult wild-type GISTs and nine pediatric/adolescent wild-type GISTs were analyzed with SDHB, and where this was negative, then with SDHA immunohistochemistry. If SDHA immunohistochemistry was negative, sequencing analysis of the entire SDHA coding sequence was performed. All nine pediatric/adolescent GISTs and seven adult wild-type GISTs were negative for SDHB immunohistochemistry. One pediatric GIST and three SDHB-immunonegative adult wild-type GISTs were negative for SDHA immunohistochemistry. In all four SDHA-negative GISTs, a germline SDHA c.91C>T transition was found leading to a nonsense p.Arg31X mutation. Our results demonstrate that SDHA immunohistochemistry on GISTs can identify the presence of an SDHA germline mutation. Identifying GISTs with deficient SDH activity warrants additional genetic testing, evaluation and follow-up for inherited disorders and paragangliomas.

Endoscopic ultrasonography-guided diagnosis of subepithelial tumors

Subepithelial lesions are frequently discovered during routine endoscopic examinations. These lesions represent a wide spectrum of heterogeneous benign to malignant conditions. Most of these lesions are asymptomatic. There is no consensus regarding how to manage these lesions. Over the last 2 decades, the approach to these lesions has significantly improved owing to the introduction of endoscopic ultrasonography, fine-needle aspiration, immunohistochemical staining methods, and different treatment options. This article discusses the nature of subepithelial lesions, focusing on the most recent developments that use endoscopic ultrasonography to diagnose and manage these lesions.

[Gastrointestinal stromal tumors]

Gastrointestinal stromal tumors (GIST) are the most common sarcomas of the gastrointestinal tract. They affect all segments of the digestive tract. They develop from the interstitial cells of Cajal. Mutations in the Kit gene is present in 86% of cases and in PDGFR gene in 15% of cases. The marker CD 117 is present in 95% of cases. Surgery is the standard treatment in localized forms. The tyrosine kinase inhibitor, imatinib is standard in first-line metastatic gastrointestinal stromal tumors, as well as adjuvant treatment after surgery. Sunitinib is the standard in second line.

Targeting the Cellular Signaling: BRAF Inhibition and Beyond for the Treatment of Metastatic Malignant Melanoma

Although advances in cytotoxic treatments have been obtained in several neoplasias, in metastatic melanoma there was no drug able to significantly change the natural history of the disease in the last 30 years. In the last decade, translational research identified important mechanisms in malignant transformation, invasion, and progression. Signaling pathways can be abnormally activated by oncogenes. The identification of oncogenic mutated kinases implicated in this process provides an opportunity for new target therapies. The melanoma dependence on BRAF-mutated kinase allowed the development of inhibitors that produced major responses in clinical trials. This is the beginning of a novel class of drugs in metastatic melanoma; the identification of the transduction signaling networking and other “druggable” kinases is in active research. In this paper, we discuss the ongoing research on cellular signaling inhibition, resistance mechanisms, and strategies to overcome treatment failure.