Curative intent treatment of late presented extragastrointestinal stromal tumor: two identical case reports with literature review

Abstract

Gastrointestinal stromal tumors (GISTs) occurring outside the gastrointestinal tract are known as extragastrointestinal stromal tumors (EGIST). They share some common histopathologic and molecular characteristics. This report describes two female patients who were suspected of having a mesenteric GIST, but opted for surveillance rather than definitive treatment. Upon reassessment, both patients demonstrated increased tumor mass with no evidence of distant metastasis. The intraoperative findings confirmed the conclusion of clinical and imaging studies performed preoperatively and radical excisions were performed. Histopathological examination (spindle cell neoplasm) and immunohistochemistry (CD117) confirmed EGIST. Both patients underwent Imatinib therapy following surgery with no evidence of disease recurrence or metastasis upon follow up. Although sharing histologic features with GIST, EGIST frequently demonstrates distinct characteristics that facilitate the proper diagnosis and management of EGIST. Since it is a rare and aggressive disease with a poor outcome, early detection and curative surgical resection remains the mainstay of treatment.

Extra-Gastrointestinal Stromal Tumor (EGIST) in the Pelvis Mimicking Retroperitoneal Sarcoma

“…1 They are discovered incidentally during investigations for abdominal pain, abdominal mass, or during a laparotomy. 3 Patient history, physical examination, appropriate blood work, and imaging studies, as well as surgical evaluation, may be included in the EGIST workup. Endoscopy and endoscopic ultrasound can be helpful in some cases.…”

“…2 An enhanced computed tomography scan usually reveals some distinguishing features, such as a large mass with peripheral enhancement of unknown origin shifting adjacent structures and possible abdominal lymphadenopathy nodes. 3 Imaging alone does not distinguish EGIST from other abdominal pathologies 3 ; to confirm the diagnosis, a percutaneous transperitoneal biopsy or an endoscopic transmural biopsy is required, 2 and immunohistochemistry studies reveal that the cells are positive for immunological markers such as CD117, DOG1, CD34, B-cell lymphoma 2, desmin, smooth muscle actin, 3 and S100. 1 The combination of CD117 and DOG1 improves significantly diagnosis accuracy.…”

“…1 The combination of CD117 and DOG1 improves significantly diagnosis accuracy. 3 The differential diagnosis tends to be broad and includes leiomyosarcoma, liposarcoma, fibrosarcoma, 2,3 solitary fibrous tumor, 2 or lymphoma. 3 The treatment of EGIST is similar to that of GIST, which consists of radical surgical en bloc resection with negative margins.…”

“…Subsequently, the pelvic magnetic resonance imaging revealed a 14.5 Â 8.6 Â 8.1cm pelvic heterogeneous exophytic mass that shows heterogeneous T2, mixed hyperand hypo-T1 signal intensities (denoting hemorrhagic components), heterogeneously enhanced and demonstrating areas of restricted diffusion on diffusion-weighted imaging (►Figs. [1][2][3].…”

“…2 The cell that gives rise to these tumors is a pluripotent mesenchymal stem cell that has been automated to differentiate into interstitial Cajal cells, 2 which are found in intestinal wall, 3 and regulate its peristalsis. 2 Extra-gastrointestinal stromal tumors (EGISTs), as the term implies, are GISTs found outside the GI tract, 2,3 representing for less than 5% of total GISTs, 3 and less than 1% of total GI tumors. 2 EGISTs are most commonly found in the omentum, mesentery, retroperitoneum, pelvic region, abdominal wall, liver, gallbladder, pancreas, bladder, seminal vesicle, vagina prostate, 3 and scrotum.…”