Gastrointestinal stromal tumors: A clinicopathologic and immunohistochemical study of 136 cases (original) (raw)
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Gastrointestinal Stromal Tumors—A Morphological and Immunohistochemical Study
Journal of Gastrointestinal Cancer, 2009
Purpose The rationale of this study was to assess the morphological and immunohistochemical characteristics of gastrointestinal stromal tumor (GIST) along with their risk stratification. Methods Record of 36 cases diagnosed as GIST over a period of 2 years (January 2007 to December 2008) was retrieved. Slides were reviewed for histological typing, immunohistochemical staining, and mitotic count. Cases were divided into very low, low, intermediate, and high-risk groups according to the Fletcher method of risk stratification (Table 1; Fletcher et al. (Int J Surg Pathol 10:81–89, 2002)). Mean, median, and mode were calculated for quantitative variables like age, tumor size, and mitotic count by using SPSS version 14. Frequencies and percentages were also calculated for qualitative variables like results of immunohistochemistry, tumor site, and histological subtypes. Results Out of 36 patients, 14 patients were male, and 22 were female. A total of 14 (39%) patients had tumor size between 2 and 5 cm, 13 (36%) patients had size between 5 and 10 cm, and 9 (25%) patients had size >10 cm. There was no tumor less than 2 cm in size. Twenty-one patients (58%) had mitoses <5/50 high power fields (HPF) while seven (20%) had mitoses between 5 and 10/50 HPF and eight (22%) >10/50 HPF. Thirty-one (86%) of cases were strongly positive for CD117 while CD34 was positive in 81% of the cases. Most frequent histological type was hypercellular spindle cell type, and most frequent site of presentation was stomach. Seven patients fell into low risk, ten patients intermediate risk, and 19 patients in high risk groups. There were no patients in very low risk group. Conclusion By using microscopy and immunohistochemical techniques, GISTs can be diagnosed accurately and treated efficiently. Risk stratification and histological subtyping have emerged as efficient tools to predict malignant behavior.
Journal of Clinical and Diagnostic Research, 2022
The GISTs arise from the interstitial cells of Cajal, the pacemaker cells, comprising <1% of all primary GIT tract neoplasms [1]. The peak age of occurrence is 60-65 years, equally affecting males and females, which may be detected incidentally radiologically or present with abdominal symptoms [2]. More than 60% of them take place in the stomach. EGIST occur in the omentum, mesentery, retroperitoneum, and perineum. Histomorphologically, GISTs are hypocellular to densely cellular lesions [1]. The identification of primary mutations in KIT (tyrosine-protein kinase) (75-80%) or Platelet-derived growth factor receptor alpha (PGFRA) (7-15%) genes by IHC has revolutionised the diagnosis and led to the development of targeted therapy [1]. The diagnosis and treatment of small GISTs are important as surgery is the mainstay of treatment in Asian countries as compared to medical therapy in western countries. Optimal treatment of GISTs requires a team effort, including gastroenterologists, surgical and medical oncologists, pathologists, and radiologists [3]. This case series was done to study the clinicopathological, histomorphological, and IHC spectrum of GISTs along with their risk stratification according to the modified Miettinen and Lasota's algorithm [4]. The American Joint Committee on Cancer (AJCC) Cancer Staging (TNM) 8 th edition was used for staging and grading [5]. Following permission from the Institutional Ethics Committee of Clinical Research (No. 289/2021) was approved, eight patients with GISTs diagnosed between January 2017 and December 2020 are presented in this case series. CASE SERIES Case 1 A 36-year-old man presented to the Department of Surgery with chief complaints of epigastric discomfort for a month and vomiting for five days. A well-defined, spherical, broad-based isoechoic lesion measuring 4.3x3.4 cm with central anechoic cystic regions was seen on Ultrasound Sonography (USG), emerging from the wall of the pylorus producing luminal compression and stomach dilatation. A comparable tumour was detected using Contrast-Enhanced Computer Tomography (CECT), which raised the probability of GIST. Based on clinical findings and radiological investigations, the possibility of GIST or leiomyoma was considered. The histopathology laboratory received a 0.5 cm size upper GI scopy biopsy which microscopically showed mainly moderate chronic inflammation with no submucosal tissue. Eventually, excision of mass with distal stomach, pylorus and omentum was performed. Grossly, a submucosal tumour in region of pylorus measuring 4.0x3.5x3.0 cm was seen. The cut surface of the tumour was well-circumscribed, greyish-white with a few cystic areas. Sections from the tumour showed spindle cells arranged in fascicles and whorls with a round to oval nucleus with minimal pleomorphism and eosinophilic cytoplasm with pointed ends [Table/Fig-1a]. Mitosis was <5 per 20-25 hpf (high power field). Omentum was free from metastasis. A diagnosis of spindle cell tumour, suggestive of GIST, grade G1, very low-risk category was given. Strong, diffuse IHC positivity for CD117 [Table/Fig-1b] and vimentin confirmed the provisional diagnosis. S-100 was weakly positive and desmin was negative, which excluded neural and smooth muscle origin tumours. For six months there was no recurrence after which the patient was lost to follow-up. Case 2 A 75 year-old-male consulted a general surgeon at the Outpatient Department (OPD) for symptoms of increased frequency of stool with difficulty in defecation for six months and weakness for one year. For 20 days he felt a mass in the left iliac fossa. On
IP innovative publication pvt. ltd, 2019
Introduction: Mesenchymal tumours of gastrointestinal tract are a heterogenous group of nonepithelial tumours of variable mesenchymal cell histogenesis. Gastrointestinal stromal tumour (GIST) is the most common primary mesenchymal tumour of the gastrointestinal tract and spans a clinical spectrum from benign to malignant. This study evaluated the clinicopathological morphological and immunohistochemical features of GIST of the intestinal tract. Materials and Methods: All evaluable cases of mesenchymal tumors of the gastrointestinal tract were studied from January 2007 to December 2012. Tissue microarray was constructed and Immunohistochemical expression of CD 117, CD 34, DOG1, SMA, S100, Ki 67 were studied. Results: Gastrointestinal stromal tumours were the most common mesenchymal tumours of the gastrointestinal tract accounting to 77.96%. The median age of presentation was 51 years with near equal sex preliction with early clinical presentation. The gastric tumours were of significantly bigger size with increased expression of CD 34. Majority of tumors were of bigger size (>10 cm, 47%) thereby increased number of tumours in high risk category (76%). Spindle cell pattern was the most common morphology (69.5%). Epitheliod histology was significantly associated with pleomorphism and atypia (p value – 0.029). Inclusion of anatomic site into the risk category will help in better stratificaion. High risk tumours showed significant areas of necrosis when compared with low risk tumours (p value- 0.0156). Tumours of older age group (>40 years) showed significant mitotic activity (p value 0.04). DOG1 is a very sensitive (97.8%) marker for GIST. A wide immunopanel with emphasis on DOG 1 positivity for precise diagnosis of GIST and classification of mes enchymal tumors of the GI tract.
Gastrointestinal stromal tumors: a clinicopathological and immunohistochemical study of 121 cases
Indian Journal of Gastroenterology, 2010
Background Primary mesenchymal tumors of the gastrointestinal tract are a heterogeneous group of tumors with a wide clinical spectrum, of which gastrointestinal stromal tumors (GIST) typically occur in middle-aged to older individuals. This study evaluated the clinicopathological and morphological features of GIST of the intestinal tract. Methods The study included 108 gastrointestinal and 13 extra-gastrointestinal stromal tumors involving the mesentry and retroperitoneum between January 1989 and July 2007. Immunohistochemical expression of CD117, CD34, SMA, Desmin, S100, and Ki-67 were studied. Results GIST comprised 108 of 120 (90%) of the mesenchymal tumors. The tumor was located in the stomach in the majority (55%) of patients followed by small intestine (30%), retroperitoneum (7%) and the colorectum (4%). There was a significant correlation between tumor size and mitotic index, with larger tumors having higher mitotic index (p<0.001). Mitotic index per 5 mm 2 correlated with high cellularity (p<0.001), presence of necrosis (p<0.001) and presence of mucosal invasion (p=0.01). Expression of CD117 was seen in 94%, CD34 in 59%, SMA in 41%, S-100 in 33%, and desmin in 4% of tumors. Conclusion We found GIST to be the most common mesenchymal tumor of the gastrointestinal tract.
Virchows Archiv, 2001
Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal (GI) tract. They are defined here as KIT (CD117, stem cell factor receptor)-positive mesenchymal spindle cell or epithelioid neoplasms primary in the GI tract, omentum, and mesentery. GISTs typically present in older individuals and are most common in the stomach (60-70%), followed by small intestine (20-25%), colon and rectum (5%), and esophagus (<5%). Benign tumors outnumber the malignant ones by a wide margin. Approximately 70% of GISTs are positive for CD34, 20-30% are positive for smooth muscle actin (SMA), 10% are positive for S100 protein and <5% are positive for desmin. The expression of CD34 and SMA is often reciprocal. GISTs commonly have activating mutations in exon 11 (or rarely exon 9 and exon 13) of the KIT gene that encodes a tyrosine kinase receptor for the growth factor named stem cell factor or mast cell growth factor. Ligand-independent activation of KIT appears to be a strong candidate for molecular pathogenesis of GISTs, and it may be a target for future treatment for such tumors. Other genetic changes in GISTs discovered using comparative genomic hybridization include losses in 14q and 22q in both benign and malignant GISTs and occurrence in various gains predominantly in malignant GISTs. GISTs have phenotypic similarities with the interstitial cells of Cajal and, therefore, a histogenetic origin from these cells has been suggested. An alternative possibility, origin of pluripotential stem cells, is also possible; this is supported by the same origin of Cajal cells and smooth muscle and by the common SMA expression in GISTs. GISTs differ clinically and pathogenetically from true leiomyosarcomas (very rare in the GI tract) and leiomyomas. The latter occur in the GI tract, predominantly in the esophagus (intramural tumors) and the colon and rectum (muscularis mucosae tumors). They also differ from schwannomas that are benign S100-positive spindle cell tumors usually presenting in the stomach. GI autonomic nerve tumors (GANTs) are probably a subset of GIST. Other mesenchymal tumors that have to be separated from GISTs include inflammatory myofibroblastic tumors in children, desmoid, and dedifferentiated liposarcoma. Angiosarcomas and metastatic melanomas, both of which are often KIT-positive, should not be confused with GISTs.
Annals of diagnostic …, 2007
It is important to distinguish gastrointestinal (GI) stromal tumors (GISTs) from other GI mesenchymal tumors (GIMTs) because of the availability of molecular-targeted therapy for GISTs. The aim of the study was to reclassify GIMTs and to determine the clinicopathologic features of GISTs in Mexico. Cases of GIMT identified from the database of 3 large diagnostic centers in Mexico between 1995 and 2004 were reclassified according to current criteria. Hematoxylin and eosin-stained sections and clinical histories were reviewed, and immunohistochemistry was performed using anti-CD117, CD34, smooth muscle actin, and S-100 protein. A total of 275 GISTs were identified. The tumors were located in the stomach (40%), small intestine (35%), colorectum (12%), abdominal cavity (11%), and esophagus (2%). There were equal numbers of men and women with a mean age at diagnosis of 61 years. The tumors ranged in size from 3.5 to 34 cm (mean, 9.1 cm); 95 tumors (34%) were larger than 10 cm. Colorectal and omental tumors were the largest. The cell types included pure spindle (68%), pure epithelioid (16%), and mixed epithelioid/spindle (14%). Whereas 17.8% of tumors were regarded as low risk, 43% of tumors were in the high-risk category. CD117 positivity was detected in most of the tumors (96%). In addition to CD117, 255 cases (92%) were positive for CD34, 82 cases (32%) were positive for smooth muscle actin, and 13 cases (4.7%) were positive for desmin. Gastrointestinal stromal tumors in Mexico have the same clinicopathologic and immunohistochemical features as those reported in other countries. It is not always easy to distinguish GISTs from other soft tissue lesions. The diagnosis can be difficult even for experienced pathologists.