Primary extragastrointestinal stromal tumour of the whole abdominal cavity, omentum, peritoneum and mesentery: a case report and review of the literature

Unusual location of gastrointestinal stromal tumor (GIST): A case report and literature review of greater omentum location

INTRODUCTION

Gastrointestinal stromal tumors (GISTs) represent a unique subset of neoplasms within the digestive tract. They can manifest in various organs throughout the digestive tract, ranging from the oral cavity to the anus, with a predilection for the stomach and small intestine. A distinct subtype of GISTs, known as Extra-gastrointestinal stromal tumors (EGISTs), originate outside the typical GIST organs such as the mesentery, retroperitoneum, and occasionally the omentum. EGISTs are relatively rare, accounting for <5 % of all GIST cases.

PRESENTATION OF CASE

We present the case of a 30-year-old female patient who presented with an upper abdominal mass associated with anorexia, fever, and weakness. Radiographic imaging revealed a cystic mass beneath the left hypochondrium. Exploratory laparoscopy confirmed the presence of an isolated mass adherent to the gastrocolic ligament and greater omentum. Histopathological examination confirmed GIST, characterized by spindle-shaped cells with DOG1 and CD117/C-kit expression. The patient underwent successful tumor resection and was discharged home with postoperative imatinib therapy. Follow-up at 14 months showed no recurrence.

DISCUSSION

The rarity of Gastrointestinal Stromal Tumors (GISTs) in the Greater Omentum highlights diagnostic challenges and underscores the need for further research. Immunohistochemical analysis aids in diagnosis, with Ki-67 staining indicating a high-risk classification. Surgery remains the primary treatment, with potential adjuvant therapy utilizing Imatinib mesylate.

CONCLUSION

Our case underscores the rare occurrence of GIST in the Greater Omentum. Despite their infrequency, EGISTs should be considered in intra-abdominal masses, emphasizing accurate diagnosis for appropriate management and the need for further research.

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.

Extra-gastrointestinal stromal tumors (EGISTs): A case report for a mischief entity

BACKGROUND

Extra-gastrointestinal stromal tumor is a rare subtype of soft tissue sarcomas with significantly variable presentation, management, and prognosis. This makes it crucial to report the different institutional experiences of encountering extra-gastrointestinal stromal tumors (EGIST).

CASE PRESENTATION

We report 3 cases of EGIST diagnosis at American University of Beirut Medical Center for 2 males and 1 female in the 5th, 6th, and 7th decades of life, respectively. For the first case, the tumor was initially suspected to be ovarian cancer, but biopsy revealed a diagnosis of EGIST, and the patient was started on neoadjuvant therapy. In the second case, the tumor was retro-gastric and prelim diagnosis was gastric cancer but again biopsy revealed an EGIST histopathology, and the patient underwent surgery and adjuvant treatment. For the third case, a previous history of testicular cancer prompted an initial suspicion of recurrence with metastasis but biopsy and immunohistochemistry staining revealed EGIST with related markers. The patient underwent treatment at a different institution in his home country.

CONCLUSION

This report sheds light on the importance of keeping EGIST amongst any differential list for abdominal and pelvic tumors. It also shows that EGIST-focused studies are needed to assess the effectiveness of the different treatment modalities available when utilized specifically for EGIST. This would allow for better oncological outcomes and improved quality of life.

Extremely Aggressive Mesenteric Extragastrointestinal Stromal Tumor: A Case Report and Literature Review

Gastrointestinal stromal tumors (GISTs) are rare tumors with increasing incidence. GIST is the most common mesenchymal tumor of the gastrointestinal tract involving the elderly population with a slow progression. It originates from the interstitial cells of Cajal. GISTs that develop outside the gastrointestinal tract and have no connections with the intestinal walls or serosal surfaces of the gastrointestinal tubular organs are referred to as extraintestinal gastrointestinal stromal tumors (EGISTs). They have similar morphological and immunohistological characteristics as GISTs. Here, we describe a unique case of an extremely aggressive mesenteric GIST in a 44-year-old African American male.

The patient presented to the hospital with complaints of generalized abdominal pain associated with 50-pound weight loss, decreased appetite, and constipation. He underwent computed tomography (CT) of the abdomen and pelvis which showed a large mass along the central mesentery measuring about 15 × 11 cm with adjacent metastatic nodal disease. He underwent a CT-guided biopsy of his abdominal mass with histopathology findings positive for c-kit (CD117) and discovered on GIST-1 (DOG-1) consistent with GIST. Based on TNM staging, his tumor was graded T4 with N1 given nodal involvement placing him as a stage IV. He was referred to an oncologist and was started on neoadjuvant therapy with imatinib. Mesenteric EGISTs, while rare, are known to have a worse prognosis compared to other EGISTs; hence, prompt action must be taken in aggressively treating these tumors. Factors such as mitotic index and tumor size affect the prognosis of mesenteric GISTs.

The expression of MDM2 in gastrointestinal stromal tumors: immunohistochemical analysis of 35 cases

Background

Gastrointestinal stromal tumors (GIST) are the most common primary mesenchymal tumors of the digestive system. The assessment of their biological behavior still remains a scientific challenge. To date, there are no well-established biological prognostic markers of GIST. Our aim is to study the expression of the MDM2 oncoprotein in GIST through an immunohistochemical analysis.

Methods

It was a retrospective study of 35 cases of GIST diagnosed from 2009 to 2012 in the department of pathology of Hassan II university hospital, Fès, Morocco. MDM2 immunohistochemical staining was performed on archival paraffin-embedded and formalin-fixed specimens (with a threshold of nuclear positivity > 10%). Analysis of correlations between MDM2 immunoexpression and clinicopathological features of GIST has been performed.

Results

The mean age was 55.23 years (range 25–84 years) with a male predominance (sex ratio = 1.5). The stomach was the main site of GIST, with 17 cases (48.57%) followed by the small bowel (9 cases, 25.71%). The spindle cell type GIST was the most frequent morphological variant (29 cases, 82.85%). Tumor necrosis was present in 8 cases (22.85%). Two patients (5.71%) had very low risk GIST, 5 (14.28%) had low risk GIST, 7 patients (20%) had intermediate risk tumors. The remaining 21 cases (60%) had high risk GIST. At the time of diagnosis, 9 patients (25.71%) had metastatic tumors. At immunohistochemical analysis, 40% of cases (14 patients) stained positive for MDM2. Of these MDMD2-positive tumors, 11/14 (78.57%) had high risk tumors and 8/14 cases (57.14%) presented with metastatic GIST. MDM2 positivity was significantly associated with the metastatic status (p = 0.001).

Conclusion

The current study suggests that MDM2 immunohistochemical expression is a negative histoprognostic factor in GIST with a statistically significant correlation with metastasis.

Extragastrointestinal stromal tumour of the lesser omentum: A case report and literature review

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EGISTs are very rare mesenchymal tumours which originate from cells outside the gastrointestinal tract and tend to have an aggressive biological behaviour.

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There have been only a few previous reports of EGISTs arising in the lesser omentum.

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Complete surgical resection is the most effective treatment associated with the use of imatinib in the presence of adverse prognostic factors.

Introduction

Extragastrointestinal stromal tumours (EGISTs) are very uncommon compared to their gastrointestinal counterparts. Most of them originate from the intestinal mesentery and the omentum.

Case report

A 70 year-old Caucasian woman presented with a bulky abdominal mass which on laparotomy was found to originate from the lesser omentum and was completely resected. Histological examination revealed spindle cells with severe pleomorphism and high mitotic activity. Immunohistochemically, the tumour cells showed strong positivity for c-kit (CD117), DOG-1 and human haematopoietic progenitor cell antigen (CD34). An exon 11 deleterious mutation was identified and thus regular dosing of 400 mg imatinib mesylate was initiated.

Discussion

There have been only a few previous reports of EGISTs arising in the lesser omentum. Although EGISTs seem to have morphological and immunohistochemical similarities with GISTs, their pathogenesis, incidence, genetic background and prognosis are not completely known because they are extremely rare. It is strongly believed that such tumours originate from cells, which have similar pathological characteristics and biological behaviour as the intestinal cells of Cajal. In most series of EGISTs, a female predominance, a greater size and a higher mitotic index than GISTs were observed.

Conclusion

EGISTs are very rare mesenchymal tumours which originate from cells outside the gastrointestinal tract and tend to have a more aggressive biological behaviour than their GI counterparts. Complete surgical resection is the most effective treatment associated with the use of imatinib in the presence of adverse prognostic factors. In any case a strict follow-up is necessary due to high recurrence rates.

Extragastrointestinal stromal tumor of the abdominal subcutaneous tissue: Report of a very rare case at an unusual site

Extragastrointestinal stromal tumors (EGISTs) are rare tumors that arise outside the digestive tract. We report a case of an EGIST arising in the subcutaneous tissue of the abdominal wall, which at this site can often be misdiagnosed as dermatofibrosarcoma protuberans. The tumor was surgically resected from a 72-year-old male Chinese Han patient, and pathological examination revealed spindle-shaped tumor cells with eosinophilic cytoplasm and an oval nucleus. Immunohistochemically, the tumor cells showed strong cytoplasmic positivity for CD34, c-KIT (CD117), and DOG1. Tests for activating mutations of GISTs showed that the tumor cells carried an in-frame deletion (NP_000213.1:p.Lys550_Gln556del) in exon 11 of c-KIT (CD117). Thus, an EGIST should be considered in patients with abdominal subcutaneous tumors with an epithelioid, spindle-shaped, or mixed morphology. Immunohistochemistry of c-KIT (CD117) and DOG1 and genetic testing for activating mutations are recommended to aid in the differential diagnosis of subcutaneous tumors. In short, although EGISTs are rare in the abdominal subcutaneous tissue, pathologists must be aware of their possibility.