Canine Gastrointestinal Stromal Tumors

Abstract

Gastrointestinal stromal tumors (GISTs), leiomyomas, and leiomyosarcomas are common mesenchymal neoplasms in the gastrointestinal (GI) tract of dogs. As previously diagnosed smooth muscle tumors of the canine GI tract are increasingly reclassified as GISTs, it becomes important to identify additional criteria that may assist in the diagnosis of these neoplasms, provide prognostic information, and offer targets for therapy. Examination of cluster of differentiation (CD), molecule expression (such as KIT [CD117] and CD34) as well as gross, histologic, and immunohistochemical features (such as tumor size, tumor location, mitotic index, AgNOR, and Ki67 labeling) in human GISTs has revealed new and valuable prognostic, diagnostic, and therapeutic information. In this study, GISTs were examined for the gross, histologic, and immunohistochemical features listed above. Forty-nine cases of canine gastrointestinal mesenchymal neoplasms from the Animal Medical Center (New York, NY) were categorized as GISTs (KIT positive), leiomyosarcoma/leiomyoma (KIT negative, smooth muscle actin [SMA], and/or desmin positive), or other (KIT, SMA, and desmin negative). A proportion (55%) of canine cases previously diagnosed as smooth muscle tumors were reclassified as GISTs according to KIT immunoreactivity. Statistical correlations with survival data were not possible because of insufficient follow-up data. However, there was a significant difference between mitotic index, AgNOR, and Ki67 scores depending on the location of the tumor (small vs large intestine). This study represents the first time CD34 immunoreactivity has been demonstrated in canine GISTs.

Predicting Metastatic Potential of Gastrointestinal Stromal Tumors in Dog by Ultrasonography

“…Tumors of Type C or Type D with large necrosis areas, which were categorized as high-risk, tended to be larger than other types of tumors. These results agree with earlier studies of canine GIST reporting that necrosis areas positively correlate with tumor size [7] and that larger tumor diameter is a negative prognostic indicator in canine GIST [12]. The negative prognosis may be a result of the aggressive nature of malignant tumors, which grow rapidly and contain large, expanding internal necrosis regions.…”

Immunohistochemical and morphological features of a small bowel leiomyoma in a black crested macaque (Macaca nigra)

“…Despite this, there are other immunohistohemical markers that could be useful in this case such as S-100, CD34 and CD117 (c-KIT). The c-KIT is expressed in gastrointestinal stromal tumor (GIST) [30,31] together with CD34 as double-positive reactivity [32] and therefore must be taken into account in the differential diagnosis. S-100 antibody is a marker of neurogenic differentiation, lacking of leiomyomas [30].…”

Intestinal gastrointestinal stromal tumor in a cat

“…GISTs are most common in the stomach (60-70%), followed by the small intestine (20-25%), colon and rectum (5%), and esophagus (<5%) in humans [14]. In dogs, GISTs occur most commonly in the large intestine, including the cecum, colon and rectum (48-67%), followed by the small intestine (29-30%) and stomach (0-19%) [5,7,18]. Only one previous report has documented the occurrence of a GIST in the stomach of a cat [17].…”