Primary Extra-gastrointestinal Stromal Tumor of Retroperitoneum

Extragastrointestinal Stromal Tumor in the Peritoneum: A Case Report

Gastrointestinal stromal tumors (GIST) are tumors of mesenchymal origin, accounting for less than 1% of the primary neoplasms of the digestive tract, which can affect any segment of the gastrointestinal tract. However, they can also occur in other locations outside the gastrointestinal tract. In such situations, these are known as extragastrointestinal stromal tumors (eGIST). We present a 58-year-old male, who attended the emergency department due to asthenia, anorexia, heartburn, abdominal pain, and distension, who was ultimately diagnosed with an eGIST in the peritoneum. The immunohistochemistry pattern of the tumor sample obtained favored this diagnosis, especially demonstrated by the positivity for discovered on GIST protein 1 (DOG1) and negativity of smooth muscle markers. Due to the rarity of extragastrointestinal tumors and the even greater rarity of those originating in the peritoneum, the authors consider this a pertinent clinical case to be published due to its originality.

Gastrointestinal Stromal Tumor (GIST) from esophagus to anorectum - diagnosis, response evaluation and surveillance on computed tomography (CT) scan

Gastrointestinal stromal tumor (GIST) are the most common non epithelial tumor of the gastrointestinal (GI) tract. They arise from interstitial cells of Cajal present in the myenteric plexus. They can also arise outside the GI tract from mesentery, retro peritoneum and omentum. With the advent of new targeted molecular therapy c- tyrosine kinase inhibitor (Imatinib), it has become important to differentiate between response and pseudo-progression of the disease as response evaluation criteria for GIST are different from Response Evaluation Criteria in Solid Tumors (RECIST). Purpose of this pictorial essay is to enumerate the characteristic CT features of GIST, and discuss atypical features and response evaluation criteria.

A rare case of extraperitoneal gastrointestinal stromal tumor arising from kidney

Mesenchymal tumors of the gastrointestinal tract which arise from the interstitial cells of Cajal and express C-Kit protein or CD117 on immunohistochemistry are known as gastrointestinal stromal tumors (GISTs). Extraperitoneal GISTs (EGISTs) are rare tumors arising from the mesentery, omentum, or retroperitoneum. We report a case of a 52-year-old male who presented with a huge abdominal lump arising from the right renal capsule that was found to be EGIST on histopathological examination and immunohistochemistry.

Laparoscopic Resection of An Extragastrointestinal Stromal Tumor in the Presacral Area

STUDY OBJECTIVE

To show a surgical video in which a retroperitoneal extragastrointestinal stromal tumor was resected with the laparoscopic approach in the presacral area.

DESIGN

A case report (Canadian Task Force classification III). The local ethics committee waived the requirement for approval.

SETTING

A very small proportion of extragastrointestinal stromal tumors (EGISTs) is located in the retroperitoneal region. There are insufficient data on the clinical and pathologic features and the long-term follow-up of these tumors [1]. There are a few cases reported in the presacral region in the literature. The gold standard treatment for EGISTs is complete surgical excision of the mass. If it is possible, en bloc excision with its surrounding tissue is very important [2].

PATIENT

A 53-year-old woman. The patient provided informed consent to use images and videos of the procedure.

INTERVENTIONS

This is a step-by-step illustration for resection of a retroperitoneal EGIST in the presacral area. The patient was a 53-year-old, gravida 3, para 3 white woman. She presented with abdominal pain for 5 months. Magnetic resonance imaging showed a 4-cm diameter solid mass localized at the presacral area. Laboratory test results for tumor biomarkers were as follows: cancer antigen (CA) 125 = 40 U/mL (normal values <35 U/mL), CA 19-9 = 29 U/mL (normal values <37 U/mL), carcinoembryonic antigen = 2.1 ng/mL (normal values <3 ng/mL), and CA 15.3 = 18 U/mL (normal values <35 U/mL). Because of malignancy suspicion, gastroscopy and colonoscopy were performed and revealed no abnormality. The Papanicolaou smear and endometrial biopsy results were negative. After preparation of the patient, laparoscopy was performed. After placement of an 11-mm umbilical port and three 5-mm abdominal ports, the pelvis and abdomen were explored and revealed a 4-cm retroperitoneal mass in the presacral area. The peritoneum overlying the presacral mass was incised and the retroperitoneum explored. Given the proximity to the mass, left ureterolysis was performed. The mass was located on the left internal iliac vein and dissected carefully. The retroperitoneal attachments were resected, and the presacral mass was removed without any complications. In order not to widen the abdominal incisions, a posterior colpotomy was performed in the cul-de-sac at equal distances from the uterosacral ligaments. An Endobag (Covidien, Dublin, Ireland) was introduced through the 5-mm port site at the posterior colpotomy. The specimen was removed in the Endobag through posterior colpotomy.

MEASUREMENTS AND MAIN RESULTS

The procedure was performed without any complications. The patient had an uneventful postoperative course and was discharged home on postoperative day 2. Pathology revealed a 4-cm retroperitoneal EGIST with negative margins. Immunohistochemistry measurements revealed hematoxylin-eosin; CD117; S100 positivity; and CD34, CD68, desmin, and DOG1 negativity. The cell type was mixed (spindle and epithelioid type). The mitotic rate was 1 to 2/50 high-power fields. The patient has been disease free since the completion of surgery.

CONCLUSION

Laparoscopic complete resection of the retroperitoneal EGIST in the presacral area is successfully performed in this patient. The patient presented by us is an example showing that minimally invasive procedures can be used in the treatment of this type of tumor in the presacral area. The key point in this operation is to control the relationship of vascular structures and a ureter with a tumor in every step to avoid any injury.

Radiological diagnosis of perinephric pathology: pictorial essay 2015

The perinephric space, shaped as an inverted cone, sits between the anterior and posterior renal fasciae. It can play host to a variety of clinical conditions encountered daily in the reporting schedule for a radiologist. Lesions may be classified and diagnosed based on their imaging characteristics, location and distribution. A broad range of differential diagnoses can be attributed to pathology sitting within this space, often without clinical signs or symptoms. An understanding of commonly encountered conditions affecting the perinephric space, along with characteristic imaging findings, can illustrate and often narrow the likely diagnosis. The aim of this essay is to describe commonly encountered neoplastic and non-neoplastic entities involving the perinephric space and to describe their key imaging characteristics.

TEACHING POINT

• Despite often a bulky disease, perinephric lymphoma does not produce obstruction or stenosis. • In primarily fatty masses, defects within the renal capsule likely represent angiomyolipoma. • Consider paraganglioma if biopsy is planned; biopsy may lead to catecholamine crisis.

The gamut of primary retroperitoneal masses: multimodality evaluation with pathologic correlation

The retroperitoneum is a large space where primary and metastatic tumors grow silently before clinical signs appear. Neoplastic retroperitoneal diseases may be solid or cystic, primary or secondary and range from benign to aggressive in behavior. Retroperitoneal neoplasms are notable for their widely disparate histologies. The solid primary retroperitoneal neoplasms are extremely uncommon and can be classified based on their tissue of origin into three main categories: mesodermal tumors, neurogenic tumors, and extragonadal germ cell tumors. These tumors can grow to a large size before clinical symptoms occur or become palpable. When symptoms do occur, they are nonspecific. The majority of these masses are malignant and imaging plays a pivotal role in the detection, staging, and pre-operative planning. Benign and malignant masses should be distinguished whenever possible to avoid unnecessary surgical procedures. Macroscopic fat, calcification, necrosis, vascularity, and neural foraminal widening are common imaging features helping for tumor differentiation. Meticulous cross-sectional imaging can triage the patient to the most appropriate therapy. Tumor morphology dictates imaging character, and biologic activity is reflected by positron emission tomography (PET). Complete surgical excision with tumor free margins is essential for long-term survival. Biopsy should be performed in consultation with surgical oncology to avoid complicating curative surgery. This pictorial essay illustrates the spectrum of multidetector computed tomography (MDCT) imaging findings in common and uncommon primary retroperitoneal masses, with an emphasis on cross-sectional imaging features for an adequate tumor characterization and staging.

Malignant Retroperitoneal Extra-Gastrointestinal Stromal Tumor: A Unique Entity

Extra-gastrointestinal stromal tumors (EGISTs) are a recently described group of tumors. A handful of less than 70 cases have been reported in English literature, so far, to the best of our knowledge. Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the alimentary canal. EGISTs are a unique entity, which require distinction from GISTs because, even though, they exhibit similar histology and immunohistochemistry to GISTs, they occur outside the gastrointestinal tract, i.e. in omentum, mesentery, retroperitoneum, etc. and have different behavior patterns as far as their prognosis and management are concerned. Retroperitoneal sub-group of EGISTs is extremely rare and we report such a case of primary malignant EGIST of the retroperitoneum which presented as a soft tissue mass on radiological evaluation. The tumor turned out to be a histopathological surprise, and could be distinctively labeled as EGIST only after morphological and immunohistochemical studies. It is imperative for radiologists, pathologists and oncologists, among other clinicians, to be able to recognize and understand the presentation of this group of tumors due to their rapid progression and poor prognosis, so that an early diagnosis and management may be able to improve the final disease outcome.

Primary extragastrointestinal stromal tumor of the pleura: A case report

Gastrointestinal stromal tumors (GISTs) are the most common type of mesenchymal tumor of the gastrointestinal tract. The stomach and small intestine are the most common sites of occurrence. GISTs are mesenchymal neoplasms originating from the interstitial cells of Cajal (ICCs), and are characterized by positivity for cluster of differentiation (CD) 117, also known as proto-oncogene c-Kit. While the majority of GISTs develop in the alimentary tract, in rare cases they may also be found in extragastrointestinal tissues. This type of GIST is known as an extragastrointestinal stromal tumor (EGIST). Despite the fact that EGISTs have been reported in the mesentery, omentum and retroperitoneum, primary intrathoracic EGISTs, arising from the pleura or lungs, are rare. The patient presented in the current study was a 40-year-old man, who presented with a cough and pyrexia, with pleural effusion on the left side. Multiple nodules throughout the parietal pleura were identified by thoracoscopy and a diagnosis of primary GIST of pleura was established, since they were positive for CD117 and discovered on GIST-1 and there was no evidence of gastrointestinal tumors. Subsequently, the patient was administered with imatinib and had no signs of disease recurrence 2 years later.

Cross-sectional Imaging Features of Primary Retroperitoneal Tumors and Their Subsequent Treatment

Basically malignant tumors in the retroperitoneal region arise from a heterogeneous group of tissues: mesodermal, neurogenic, germ cell, and lymphoid. Although rare, benign tumors and cystic masses can be also encountered in retroperitoneal space. Developments in computed tomography (CT) and magnetic resonance imaging (MRI) have contributed to both diagnosis and staging of the retroperitoneal tumors. High spatial resolution and superiority in calcification make CT indispensable; on the other hand, MRI has a better soft-tissue contrast resolution which is essential for the assessment of vascular invasion and tissue characterization. The aim of this article is to review the CT and MRI features of retroperitoneal tumors and their subsequent management.

Gastrointestinal stromal tumor (GIST) mistaken for pancreatic pseudocyst - case report and literature review

Key Clinical Message

A 74-year-old female patient underwent a Roux-en-Y cystjejunostomy for pancreatic pseudocyst developed several melena episodes and she was surgically reappraised. The main diagnostic concern was a pancreatic cystic neoplasm. A 12 × 8.0 × 5.0 cm retro-gastric lesion was resected and pathology report indicated an unsuspected gastrointestinal stromal tumor (GIST). The report aimed to describe an atypical presentation of GIST.

Retroperitoneal extragastrointestinal stromal tumor: radiologic pathologic correlation

Neoplasms with histology and immunohistochemistry similar to gastrointestinal stromal tumors may occur primarily outside the gastrointestinal tract, usually in the omentum and mesentery. These are referred to as extragastrointestinal stromal tumors (EGISTs). Retroperitoneum is a very rare site for such neoplasms. We report a patient with EGIST in the retroperitoneum, elaborating the cross-sectional imaging and histopathologic findings.

Surgical resection should be taken into consideration for the treatment of small gastric gastrointestinal stromal tumors

BACKGROUND

The National Comprehensive Cancer Network (NCCN) recommends conservative follow-up for gastric gastrointestinal stromal tumors (GISTs) less than 2 cm. The aim of the present study was to investigate the clinical and pathological features of small gastric GISTs, re-evaluate the risk potential, and discuss the treatment strategy of small gastric GISTs.

METHODS

In this retrospective study, 63 cases of small gastric GISTs (less than 2 cm) were resected surgically from May 2010 to March 2013 in our department. Clinicopathological factors were collected and the malignant potential of small gastric GISTs was analyzed.

RESULTS

The mitotic index of 14 out of 63 cases (22.22%) exceeded 5. The malignant potential of small gastric GISTs was related to tumor location (P = 0.0218). The mitotic index of 4 out of 8 GISTs (50%) located in gastric cardia exceeded 5, 8 out 28 GISTs (28.57%) located in the gastric fundus exceeded 5, and only 2 out of 27 GISTs (7.41%) located in the gastric body exceeded 5. We also discovered a good consistency between mitotic index and Ki-67 expression of small gastric GISTs.

CONCLUSIONS

Gastric GISTs less than 2 cm also have malignant potential. Thus, we recommended surgical resection of all small gastric GISTs once diagnosed.