Gastrointestinal stromal tumours: etiology, pathology and clinical management

Transvaginal excision of rectal stromal tumors: case reports and a literature review

Background

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Rectal locations are very rare, and minimally invasive surgery is a good choice for the treatment of rectal GISTs.

Case presentation

Two women each had a mass located on the lower vaginal-rectal space as determined by transvaginal ultrasound (TV-US), pelvis MR imaging, and colonoscopy. The patients successfully underwent transvaginal excision. The spindle-shaped cells were found in pathological test. The immunohistochemical analysis showed that CD117 and Dog-1 were stained positively. These results confirmed the masses as GISTs. The postoperative period was uneventful without anal dysfunction. Two patients were received adjuvant treatment with imatinib after surgery.

Conclusion

Transvaginal excision could be a minimally invasive and safe alternative treatment in the management of rectal GISTs in lower locations.

Management of a case of high-risk gastrointestinal stromal tumor in rectum by transanal minimal invasive surgery

BACKGROUND

Rectal gastrointestinal stromal tumor (GIST) is a very rare tumor of gastrointestinal tract. Surgical management of rectal GIST requires special attention for preserving of anal and urinary functions. Transanal minimal invasive surgery (TAMIS) is a well-developed minimally invasive technique for local excision of benign and early malignant rectal tumors; however, the application of TAMIS for rectal GIST is rarely and inadequately reported. We report the novel application of TAMIS for rectal GIST with considerations for anal and urinary functions.

CASE PRESENTATION

A 67 years old female, who presented with history of per rectal bleeding, was diagnosed with submucosal GIST of 4.5 cm in diameter at right posterior wall of 7 cm from anal verge. Histology of biopsy showed abundant spindle-shaped cells arranged in bundles that were positive for CD34 and negative for C-Kit, desmin, smooth muscle actin (SMA), and S-100. The tumor was excised by TAMIS successfully. Final histopathology showed pT2 tumor with C-Kit positive and mitosis count 10 per 50 HPF. Postoperative period was uneventful, and she was discharged on adjuvant imatinib mesylate for 3 years.

CONCLUSION

TAMIS can be used safely in the management of rectal GIST after appropriate evaluation of tumor size, extent, location, and experience of operating surgeon.

Epidemiology of gastrointestinal stromal tumors in a defined Canadian Health Region: a population-based study

The aim of this study was to determine the incidence and the clinical and pathological features of gastrointestinal stromal tumors within a nonselected, well-defined Canadian Health Region. A population-based cohort study of all adult patients diagnosed with gastrointestinal stromal tumors was conducted in the Calgary Health Region from April 2000 to March 2004. All charts and pathological specimens were reviewed for clinical, histological, and antigenic features. The age-adjusted and gender-adjusted annual incidence rate was 0.91/10(5) person-years. There was a trend for increased incidence with routine use of CD117. The only identified risk was advancing age (age >or=50; rate ratio = 4.6; P = .0006). All samples were positive for CD117. At presentation, 19% were at intermediate and 19% were at high risk of becoming malignant, with 14% being overtly metastatic. This is the first North American study to define the incidence and the clinical and pathologic features of gastrointestinal stromal tumors based on current diagnostic criteria.

Interstitial cells of Cajal in health and disease. Part II: ICC and gastrointestinal stromal tumours

Mesenchymal tumours in the gastrointestinal tract have long been problematic in terms of diagnosis, prognosis and therapy, but recent advances in immunohistochemistry and related therapies have allowed more specific diagnosis. In particular, the recognition that both the interstitial cells of Cajal (ICC) and many gastrointestinal stromal tumours (GISTs) are positive for c-kit and CD34 and have other features similar to those of ICC has led to the use of imatinib, a novel small molecule therapy that blocks the CD117/c-kit tyrosine kinase receptor, which shows remarkable efficacy in treatment of malignant and metastatic GISTs as well as other malignancies.

Gastrointestinal stromal tumors: a contemporary review

The literature on gastrointestinal stromal tumors (GISTs) has rapidly expanded and has demonstrated how scientific advancements in diagnosis can revolutionize the understanding of disease, while paving the way for effective treatment. While KIT (CD117) immunohistochemistry has established our definition of GISTs, molecular genetics continue to refine it. Elucidation of the aberrant receptor tyrosine kinase (RTK) model of GIST pathogenesis through mutations in c-kit and platelet-derived growth factor alpha PDGFRalpha proto-oncogenes has been prerequisite to the use of imatinib mesylate (STI571, Gleevec; Novartis, Switzerland), a molecular inhibitor of several tyrosine kinases, in the treatment of GISTs. In addition to providing a means for effective treatment, clarification of the molecular pathology of GISTs may potentially offer a new classification of these tumors by correlating genotype with histological, immunohistochemical, and clinical phenotype. This article seeks to review current knowledge of GISTs, offering a practical guide to their diagnosis and describing current epidemiological, molecular biological, and therapeutic aspects.

Gastrointestinal stromal tumours: consensus statement on diagnosis and treatment

In the multidisciplinary management of gastrointestinal stromal tumours (GISTs), there is a need to coordinate the efforts of pathology, radiology, surgery and oncology. Surgery is the mainstay for resectable nonmetastatic GISTs, but virtually all GISTs are associated with a risk of metastasis. Imatinib 400 mg/day with or without surgery is the recommended first-line treatment for recurrent or metastatic GIST; a higher dose may be considered in patients who progress, develop secondary resistance or present with specific genotypic characteristics. Adjuvant or neoadjuvant imatinib is not advised for resectable nonmetastatic GISTs. Neoadjuvant imatinib may be considered when surgery would result in significant morbidity or loss of organ function. Follow-up computed tomography imaging is recommended every three to six months for at least five years. Patients with metastatic disease should be continued on imatinib due to the high risk of recurrence on discontinuation of therapy. Treatment should be continued until there is progression or intolerable adverse effects. If dose escalation with imatinib fails, a clinical trial with novel agents alone or in combination may be considered. The present recommendations were developed at a surgical subcommittee meeting and a subsequent full Advisory Committee meeting held in Toronto, Ontario, in April 2005, under the sponsorship of Novartis Pharmaceuticals Canada Inc.