Gastrointestinal Stromal Tumors of the Equine Cecum

2001 ◽  
Vol 38 (2) ◽  
pp. 242-246 ◽  
Author(s):  
S. Hafner ◽  
B. G. Harmon ◽  
T. King

Ten cecal tumors were identified during the postmortem examination of seven horse carcasses at slaughter (one horse had three tumors). The multinodular and hemorrhagic tumors ranged from 1 to 10 cm in diameter and consisted of spindle cells arranged in thin, interconnected trabeculae that were often separated by sinuses filled with mucinous fluid, erythrocytes, and siderophages. Spindle cells of all tumors were immuno-positive for vimentin, neuron-specific enolase, and c-kit protein but lacked reactivity with antibodies to glial fibrillary acidic protein, S100 protein, and desmin. In one tumor, spindle cells diffusely bound antibodies to synaptophysin. Most tumors contained focal reactivity to smooth muscle actin antibodies; one tumor reacted diffusely. Ultrastructurally, tumor cells were connected by desmosome-like structures and exhibited extended cell processes; some contained dense core neurosecretory granules. These equine stromal tumors appeared to share some characteristics with human gastrointestinal stromal tumors.

2019 ◽  
Vol 31 (6) ◽  
pp. 879-882
Author(s):  
Mariarita Romanucci ◽  
Sabrina V. P. Defourny ◽  
Marcella Massimini ◽  
Laura Bongiovanni ◽  
Giovanni Aste ◽  
...  

A large, ill-defined, firm, multinodular mass involving the pancreas was confirmed on postmortem examination of a 5-y-old, male Rottweiler that died following acute respiratory distress syndrome, after a period of anorexia and lethargy. Histologically, the mass consisted of plump spindle cells admixed with a variable number of macrophages, lymphocytes, plasma cells, and neutrophils. Foci of coagulative necrosis and hemorrhage were also observed. Spindle cells strongly reacted to antibodies against vimentin, α–smooth muscle actin, and calponin, whereas desmin was expressed only mildly and focally. Pan-cytokeratin, KIT, glial fibrillary acidic protein, and S100 protein were nonreactive. Variable numbers of MAC 387–positive cells, CD3+ lymphocytes, and numerous blood vessels were also detected throughout the mass. Histologic and IHC findings were consistent with a diagnosis of inflammatory myofibroblastic tumor of the pancreas.


2015 ◽  
Vol 68 (11-12) ◽  
pp. 413-417 ◽  
Author(s):  
Vlado Janevski ◽  
Redzep Selmani ◽  
Vesna Janevska ◽  
Liljana Spasevska ◽  
Julija Zhivadinovik

Introduction. Gastrointestinal stromal tumors are the most common mesenchymal tumors of the digestive tract. Leiomyosarcomas of the gastrointestinal tract are rare mesenchymal neoplasms which grossly and histologically resemble gastrointestinal stromal tumors. They may be differentiated from gastrointestinal stromal tumors by using immunohistochemistry and they are typically positive for ? smooth muscle actin and desmin and negative for c-kit, CD34 and DOG1.1. They often express calponin and h-caldesmon. Case Report. We present a case of a 59-year-old male with anemia, weight loss, intermittent abdominal pain and right abdominal mass. Colonoscopy revealed an exophytic ulcerated neoplastic mass in the ascending colon and abdominal computed tomography scan showed an ill-defined heterogeneous tumor mass which surrounded almost the whole ascending colon. The patient underwent right hemicolectomy and partial resection of ileum. Histopathological examination revealed a leiomyosarcoma composed of atypical spindle cells positive for ? smooth muscle actin, desmin and vimentin, and negative for c-kit, CD34, S100 and neuron specific enolase. The patient is alive 8 months after the operation, undergoing chemotherapy. Conclusion. We have concluded that the multimodal approach comprising chemotherapy and complete surgical resection controls the leiomyosarcomas.


2002 ◽  
Vol 126 (10) ◽  
pp. 1189-1192 ◽  
Author(s):  
Vinod B. Shidham ◽  
Mamatha Chivukula ◽  
Dilip Gupta ◽  
R. Nagarjun Rao ◽  
Richard Komorowski

Abstract Context.—The differential diagnosis of gastrointestinal stromal tumors (GIST) and solitary fibrous tumors (SFT) may be a diagnostic challenging because of overlapping clinicopathologic features. Many studies have shown consistent immunoreactivity for CD117 (c-Kit) in GIST. However, only a few studies have evaluated CD117 expression in SFT, and these studies have used an antibody from Santa Cruz Biotechnology. In non-GIST lesions, reactivity with this antibody has been shown to differ from that with a CD117 antibody from Dako Corporation. The immunoreactivity of SFT with the Dako CD117 antibody has not been reported. Conversely, CD99 is a marker for SFT, and its expression in GIST has not been evaluated. Objective.—To study the immunohistochemical profiles of GIST and SFT to evaluate their diagnostic overlap. Design.—We studied the immunoreactivity of 27 unequivocal GIST and 19 unequivocal extra-abdominal SFT for CD117, CD34, CD99, α-smooth muscle actin, vimentin, CD31, S100 protein, and muscle-specific actin. All antibodies, including CD117, were from Dako Corporation. Results.—We found positive immunoreactivity for CD117 in 100% of GIST and none of SFT; for CD34 in 89% of GIST, and 100% of SFT; for CD99 in 89% of GIST and 100% of SFT; for α-smooth muscle actin in 48% of GIST and 31% of SFT; for vimentin in 89% of GIST and 90% of SFT; and for muscle-specific actin in 22% of GIST and none of SFT. None of the GIST or SFT showed immunoreactivity for CD31 and S100 protein. Conclusions.—The major difference between GIST and SFT was strong CD117 immunoexpression in all GIST and an absence of this expression in all SFT. With the exception of muscle-specific actin, the prevalence of immunoreactivity for the markers studied did not differ substantially between these 2 tumors. We conclude that GIST and SFT show distinctly divergent immunoprofiles with respect to CD117 and muscle-specific actin.


2015 ◽  
Vol 68 (11-12) ◽  
pp. 418-420 ◽  
Author(s):  
Nada Dimkovic ◽  
Danijela Bojic ◽  
Petar Svorcan ◽  
Aleksandar Jankovic ◽  
Petar Djuric ◽  
...  

Introduction. Gastrointestinal stromal tumors are the most common mesenchymal tumors of the digestive tract. Leiomyosarcomas of the gastrointestinal tract are rare mesenchymal neoplasms which grossly and histologically resemble gastrointestinal stromal tumors. They may be differentiated from gastrointestinal stromal tumors by using immunohistochemistry and they are typically positive for ? smooth muscle actin and desmin and negative for c-kit, CD34 and DOG1.1. They often express calponin and h-caldesmon. Case Report. We present a case of a 59-year-old male with anemia, weight loss, intermittent abdominal pain and right abdominal mass. Colonoscopy revealed an exophytic ulcerated neoplastic mass in the ascending colon and abdominal computed tomography scan showed an ill-defined heterogeneous tumor mass which surrounded almost the whole ascending colon. The patient underwent right hemicolectomy and partial resection of ileum. Histopathological examination revealed a leiomyosarcoma composed of atypical spindle cells positive for ? smooth muscle actin, desmin and vimentin, and negative for c-kit, CD34, S100 and neuron specific enolase. The patient is alive 8 months after the operation, undergoing chemotherapy. Conclusion. We have concluded that the multimodal approach comprising chemotherapy and complete surgical resection controls the leiomyosarcomas.


2003 ◽  
Vol 40 (1) ◽  
pp. 42-54 ◽  
Author(s):  
D. Frost ◽  
J. Lasota ◽  
M. Miettinen

Fifty canine gastrointestinal (GI) mesenchymal tumors were examined to determine the occurrence of leiomyomas (LM) and GI stromal tumors and to compare their clinicopathologic features. Twenty-one tumors (42%) were histologically reclassified as gastrointestinal stromal tumors (GISTs) and 29 tumors (58%) as LMs on the basis of their histologic similarity with homologous human tumors. The GISTs occurred equally in males and females, with a mean age of 11 years (range 5–14 years). Five GISTs (24%) were associated with clinical signs and six (29%) had metastasis in liver or abdominal cavity. The GISTs occurred in large intestine (10, 48%), small bowel (six, 29%), stomach (four, 19%), and mesentery of small intestine (one, 5%). Histologically, they were highly cellular spindle, or less commonly epithelioid tumors with mitotic rates ranging from 0 to 19 per 10 HPF. Eleven tumors (52%) were positive for CD117 (KIT); seven (33%) were positive for smooth muscle actin but none for desmin and S-100 protein. Sequences of KIT exon 11, often mutated in human GISTs, were evaluated from four GISTs. Deletion of Try556-Lys557 coexisting with duplication of Gln555 in one case of GIST and T to C transition resulting in substitution of Pro for Leu575 in another were identified. The LMs occurred predominantly in males (82%) with a mean age of 11 years (range 8–17 years). Nine tumors (31%) had associated clinical signs. They occurred in the stomach (22, 76%), esophagus (four, 14%), and intestines (three, 10%); all were paucicellular, had no mitoses, and were composed of mature smooth muscle cells. Twenty-eight (97%) were positive for smooth muscle actin and 18(62%) for desmin but none for CD117 and S-100. Both GISTs and true LMs occur in the GI tract of dogs. Both tumors have distinctive pathologic features.


1997 ◽  
Vol 34 (4) ◽  
pp. 303-311 ◽  
Author(s):  
R. G. LaRock ◽  
P. E. Ginn

Sections from 35 formalin-fixed, paraffin-embedded, canine gastrointestinal stromal tumors consisting of 14 leiomyomas (five stomach, three small intestine, two colon, four rectum), 18 leiomyosarcomas (one stomach, five small intestine, nine cecum, three rectum), two undifferentiated sarcomas (two stomach), and one neurofibrosarcoma (small intestine) were examined for the expression of vimentin, S-100 protein, α-smooth muscle actin, and desmin via immunoperoxidase methodology using an avidin-biotin complex technique. The leiomyomas were 4/14 (29%) vimentin-positive, 3/14 (21%) S-100 protein-positive, 10/14 (71%) α-smooth muscle actin-positive and 13/14 (93%) desmin-positive. Leiomyosarcomas were 18/18 (100%) vimentin-positive, 11/18 (61%) S-100 protein-positive, 9/18 (50%) α-smooth muscle actin-positive, and 15/18 (83%) desmin-positive. The undifferentiated sarcomas were 2/2 (100%) vimentin-positive, 2/2 (100%) S-100 protein-positive, 1/2 (50%) α-smooth muscle actin-positive, and 0/2 (0%) desmin-positive. The neurofibrosarcoma was vimentin and S-100 protein-positive and α-smooth muscle actin- and desmin-negative. Thirty-one of thirty-five (89%) of all neoplasms demonstrated reactivity for either desmin and/or α-smooth muscle actin. S-100 protein reactivity occurred in 17/35 (49%) of all specimens. Lack of desmin and α-smooth muscle actin reactivity occurred in 4/35 (11%) of all specimens, all of which were vimentin-positive. The immunohistochemical results indicate that the majority of canine gastrointestinal stromal tumors (GIST) with light microscopic features of smooth muscle cells have immunohistochemical staining patterns supporting smooth muscle differentiation. Vimentin reactivity correlated with a light microscopic diagnosis of malignancy. The lack of smooth muscle cell markers in some tumors and the high percentage of cases positive for S-100 protein may suggest a more complex histogenesis or differentiation for subgroups of these tumors.


2021 ◽  
Vol 49 (8) ◽  
pp. 030006052110278
Author(s):  
Shaofei Ma ◽  
Jing Wang ◽  
Zhanjun Lu ◽  
Chaoying Shi ◽  
Daohua Yang ◽  
...  

Objective This article aimed to study the clinicopathological features, immunophenotypes, and differential diagnoses of plexiform fibromyxoma (PF). Methods We searched clinical and pathology databases of our hospital for patients with histologically confirmed PF from 2007 to 2020 and reviewed the relevant English and Chinese language literature. Results Two cases of PF were identified, a 67-year-old woman and a 23-year-old man. Both patients presented with melena and anemia and underwent partial gastrectomy. Histologically, the tumors exhibited a plexiform growth pattern in the gastric submucosa and the presence of bland-looking spindle cells in the fibromyxoid stroma with the formation of small blood vessels. Immunohistochemically, the two cases were strongly positive for vimentin, smooth muscle actin, and muscle-specific actin and negative for CD117, discovered on gastrointestinal stromal tumors protein 1, CD34, CD10, S100, desmin, H-caldesmon, estrogen receptor, progesterone receptor, β-catenin, and cytokeratin. Conclusions PF is a rare mesenchymal tumor of the stomach that can be distinguished from other gastrointestinal mesenchymal tumors based on its distinctive morphology and immunophenotype.


2021 ◽  
pp. 106689692110313
Author(s):  
Alexander M. Strait ◽  
Julia A. Bridge ◽  
Anthony J. Iafrate ◽  
Marilyn M. Li ◽  
Feng Xu ◽  
...  

Myofibroblastoma is a rare, benign stromal tumor with a diverse morphologic spectrum. Mammary-type myofibroblastoma (MTMF) is the extra-mammary counterpart of this neoplasm and its occurrence throughout the body has become increasingly recognized. Similar morphologic variations of MTMF have now been described which mirror those seen in the breast. We describe a case of intra-abdominal MTMF composed of short fascicles of eosinophilic spindle cells admixed with mature adipose tissue. The spindle cells stained diffusely positive for CD34, desmin, smooth muscle actin, and h-caldesmon by immunohistochemistry. Concurrent loss of RB1 (13q14) and 13q34 loci were confirmed by fluorescence in situ hybridization whereas anchored multiplex PCR and whole transcriptome sequencing did not reveal any pathognomonic fusions suggesting an alternative diagnosis. To the best of our knowledge this is the first documented case of leiomyomatous variant of MTMF.


2001 ◽  
Vol 125 (11) ◽  
pp. 1494-1496
Author(s):  
Ravindra Veeramachaneni ◽  
Janis Gulick ◽  
Ari O. Halldorsson ◽  
Thanh T. Van ◽  
Ping L. Zhang ◽  
...  

Abstract This report describes a benign myoepithelioma of the lung that occurred in a 60-year-old woman. The patient had experienced hoarseness for 6 weeks, and a computed tomographic scan showed a nodule of approximately 2 cm in diameter at the peripheral portion of her right upper lung. Positron emission tomography showed no uptake of F-18 fluorodeoxyglucose in the nodule. Wedge biopsy of the lesion showed benign spindle cells arranged in a whorled pattern. The cells were positive for both cytokeratin and smooth muscle actin, which corresponded to the presence of tonofilaments and myofilaments that were identified ultrastructurally. The features of the present case of benign myoepithelioma that differ from features of previously reported benign and malignant cases of myoepithelioma in the lung are discussed in the report.


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