• Extragastrointestinal GIST
• GIST
• Gatrointestinal Stromal tumors
• Pancreatic GIST

• Humans
• Gastrointestinal Stromal Tumors/pathology
• Gastrointestinal Stromal Tumors/mortality
• Middle Aged
• Pancreatic Neoplasms/pathology
• Pancreatic Neoplasms/mortality
• Pancreatic Neoplasms/therapy
• Female
• Male
• Aged
• Adult

Gastrointestinal stromal tumors (GISTs) are rare tumors and rarely occur outside of the gastrointestinal (GI) tract. When GISTs originate from outside the GI tract, they are called extra-gastrointestinal stromal tumors (EGISTs). In this article, we discuss a case of a 74-year-old woman who presented due to a growing pancreatic lesion on imaging and was subsequently diagnosed with pancreatic EGIST on endoscopic ultrasound with fine-needle aspiration.

• Pancreas
• extragastrointestinal tumor
• stromal tumor

Extra-gastrointestinal stromal tumor is defined as a mesenchymal neoplasm arising from soft tissues outside the gastrointestinal tract. Prostatic extra-gastrointestinal stromal tumor has rarely been noted.

A 56 year-old man presented with pain in the anal region. A digital rectal examination revealed that the prostate was markedly enlarged with a smooth, bulging surface. Computerized tomography images showed a 6 cm heterogeneous, infiltrative tumor within the prostate gland extending to the trigon of the bladder, left seminal vesicle and rectum. The tru-cut biopsy of the prostate was reported as leiomyoma. It was decided to perform surgery and the masses were easily and completely removed from the adjacent structures. The case was reported as extra-gastrointestinal stromal tumor within the intermediate- risk category with free surgical margins. Four years after the surgery, a locoregional failure was observed and treated with imatinib.

Stromal tumor, although rare, should be considered in the differential diagnosis in patients with an enlarged prostate.

• Extra gastrointestinal stromal tumor
• prostate gist.

• Diagnosis
• Gastrointestinal stromal tumor
• Pancreas
• Pancreatectomy
• Pancreatic neoplasm

• CD34
• DOG1
• Extragastrointestinal stromal tumor
• abdominal subcutaneous
• activating mutation
• c-KIT (CD117)
• dermatofibrosarcoma protuberans

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract and usually occur in the stomach and the small intestine. The pancreas is an extremely rare primary site for GISTs and there are 25 reported cases of pancreatic GIST with most being treated with surgical resection. We describe a 52-year-old African-American female who was diagnosed with limited stage small cell carcinoma in November 2009 and treated with concurrent cisplatin/etoposide chemotherapy and radiation. She subsequently achieved complete remission. Two years later she was diagnosed with localized pancreatic GIST by endoscopic ultrasonography guided fine needle aspiration. We treated her with a tyrosine kinase inhibitor (TKI) imatinib 400 mg oral dose daily as she declined surgery. Her disease is stable based on computed tomography imaging scans 40 months after diagnosis without any metastasis. To the best of our knowledge, our case is the second case of localized pancreatic GIST treated with TKI monotherapy.

Gastrointestinal stromal tumors (GIST) are mesenchymal neoplasms of the gastrointestinal tract (GI) that are defined, in part, by the expression of CD117, a c-Kit proto-oncogene protein. GISTs emerge outside of the GI at a very low frequency, typically in a single organ or location. GISTs that occasionally emerge outside of the GI are classified as extra-gastrointestinal stromal tumors (EGIST). The present study reports an extremely rare case of EGIST detected in the pancreas and the liver. The pancreatic and liver tumors were 4.5×2.5 cm and 2.0×1.5 cm in size, respectively. Both tumors consisted of CD117-positive spindle cells with a similar mitotic rate of 1–2 per 50 high power fields. The pancreatic and the hepatic EGISTs were at a low risk of malignancy, and both tumors were proposed to be primary stromal tumors. To the best of our knowledge, this is the first report of likely primary EGIST identified in the pancreas and liver of the same patient.

• CD117
• extra-gastrointestinal stromal tumors
• gastrointestinal stromal tumors
• interstitial cells of Cajal
• metastasis
• primary tumor

AIM: To provide an overview of the literature on pancreatic extragastrointestinal stromal tumors (EGISTs).

METHODS: We report a case of pancreatic EGIST and review published studies on pancreatic EGIST accessed via the PubMed, MEDLINE, Google Scholar, and Google databases. The keywords used were “pancreas and GIST”, “pancreas and extra GIST”, “pancreas and gastrointestinal stromal tumor”, and “pancreas and extragastrointestinal stromal tumor”. Literature reviews and/or duplicate studies were excluded. The search included articles published in the English language between January 1, 2000 and May 15, 2014.

RESULTS: From our literature survey, 30 manuscripts on pancreatic EGISTs were considered, of which 27 met the search criteria and three were excluded. The studies involved 30 patients (15 men, 15 women) with a mean age of 55.3 ± 14.3 years (range 30-84 years). The mean age of the male patients was 50.8 ± 13.7 years (range 30-84 years); that of the female patients was 59.9 ± 13.3 years (range 38-81 years). Tumor dimensions were obtained for 28 cases (mean 114.4 ± 78.6 mm; range 20-350 mm). Tumors were diagnosed incidentally in 23.3% of patients; abdominal discomfort and weight loss were the major complaints in symptomatic patients. Risk of aggressive behavior according to Fletcher criteria was determined in 25 of 30 patients (68%: high risk, 28%: intermediate risk, 4%: low risk). Histopathological examination revealed the presence of spindle cells in 96.1% of cases; CD117 and CD34 were present immunohistochemically in 96.6% and 84% of patients, respectively. The most common surgical procedures were distal pancreatectomy with splenectomy (n = 9) and pancreaticoduodenectomy (n = 7). The total follow-up period for the 28 patients ranged from 3-66 mo, during which locoregional or distant metastases were diagnosed in six patients and two patients died.

CONCLUSION: Studies on EGISTs have only been published in the last decade. The lack of studies with large patient cohorts and long-term follow-up limits evidence-based commentary. In theory, each case should be assessed individually and further genetic and immunohistochemical studies are needed.

• Gastrointestinal stromal tumor
• Extra-gastrointestinal stromal tumor
• Pancreas
• Imatinib mesylate
• CD117

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract, arising from the interstitial cells of Cajal (ICCs), primarily in the stomach and small intestine. The growth of most GISTs is driven by the mutations of genes encoding oncogenic receptor tyrosine kinase KIT or platelet derived growth factor receptor alpha (PDGFRα). The pathogenesis of GISTs may involve ICCs, microRNAs (miRNAs), signaling pathways, DNA methylation, and KIT or PDGFRα gene mutations. This article systematically describes the advances in research of GISTs in terms of clinical features, imaging characteristics, endoscopic features, histopathological features, diagnosis and therapies.

• Gastrointestinal stromal tumors
• Pathogenesis
• Diagnosis
• Therapy

• differential diagnosis
• gastrointestinal stromal tumor
• pancreas
• pancreatectomy
• pancreatic neoplasms

• Aged
• Female
• Gastrointestinal Stromal Tumors/pathology
• Gastrointestinal Stromal Tumors/surgery
• Humans
• Pancreatic Neoplasms/pathology
• Pancreatic Neoplasms/surgery
• Prognosis
• Tomography, X-Ray Computed