@Article{,
AUTHOR = {Gustavo de la Roza, Asghar Naqvi, Kimball Clark},
TITLE = {Gastrointestinal stromal tumors presenting as a prostatic mass},
JOURNAL = {Canadian Journal of Urology},
VOLUME = {16},
YEAR = {2009},
NUMBER = {1},
PAGES = {4502--4506},
URL = {http://www.techscience.com/CJU/v16n1/62224},
ISSN = {1488-5581},
ABSTRACT = {Gastrointestinal stromal tumors (GISTs) are a rare and 
heterogeneous group of spindle cell neoplasms that have 
also been reported outside of gastrointestinal (GI) tract. 
These tumors are characterized by somatic mutations of 
c-KIT (CD117), a proto-oncogene that encodes a receptor 
tyrosine kinase normally expressed in the interstitial cell 
of Cajal that control the GI smooth muscle peristalsis, 
and an exquisite sensitivity to the action of the tyrokinase 
inhibitor imatinib mesylate (STI571; Gleevec). We report 
two cases of gastrointestinal stromal tumor identifi ed on 
prostatic biopsies, where a primary prostatic sarcoma was 
considered in the differential diagnosis. In one of the cases, 
there was extensive local disease involving prostate, rectum, 
and pelvic wall, as well as metastatic disease that quickly 
lead to the patient’s death despite aggressive treatment with 
imatinib mesylate and conventional chemotherapy. In the 
other case, the tumor was mostly confi ned to the rectum 
but also focally extended into the prostate capsule. The 
patient underwent resection and was alive without disease 
18 months after surgery. In both cases, tissue samples from 
prostate and the rectum showed a malignant spindle cell 
neoplasm, which was positive for CD117 (c-kit). Given 
their unique clinical management, gastrointestinal stromal 
tumors should be considered in the differential diagnosis of 
spindle cell lesions on prostatic needle biopsies and CD117 
should be added to the immunohistochemical panel in the 
work-up of such lesions to avoid misinterpreting them as 
primary prostatic neoplasms.},
DOI = {}
}