1/4. Malignant gastrointestinal stromal tumor of the gallbladder.gastrointestinal stromal tumors (GISTs) of the gallbladder are representative of an extremely rare group of tumors. We have encountered a patient with a malignant GIST of the gallbladder and presented it with a review of some articles. A 72-yr-old woman initially presented with right upper quadrant abdominal pain, fever and chills. Emergency cholecystectomy was performed under the impression of gallbladder empyema. liver metastasis was found at 7 months postoperatively and the patient expired 9 months after the surgery. At the time of cholecystectomy, the gallbladder showed a necrotic serosal surface with an irregular thickened wall. A mass, 6 cm in length and 3 cm in width, encircled the whole wall of the neck and upper body of the gallbladder. Microscopic findings revealed frequent mitotic figures (more than 20/50 HPF) and tumor necrosis. Hyperchromatic, pleomorphic and spindle shaped neoplastic cells that were arranged in a pattern of short fascicles infiltrated the entire layer of the gallbladder. The tumor cells were immunoreactive for CD117 antigen (c-kit protein) and vimentin. They were negative for desmin, smooth muscle actin and S-100 protein. Mutations of the c-kit proto-oncogene were not found in this case. These findings were sufficient to provide enough clinical, histopathological and immunohistochemical evidence in diagnosing our case as a malignant GIST.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/4. A gastrointestinal stromal tumor in the stomach: usefulness of computed tomographic volumetry.We report herein the case of a 70-year-old man who was found to have a gastrointestinal stromal tumor (GIST) in the stomach following sigmoid colon resection. Preoperative gastroscopic and barium examinations revealed a submucosal tumor, measuring 10 cm, on the upper part of the stomach. Using computed tomography (CT) images (i.e., computed tomographic volumetry) the doubling time of this tumor was calculated, accurately, as 3.3 months, which suggested a high growth rate and malignancy. A laparotomy and partial gastric resection were performed. Histologically, the tumor consisted of spindle-shaped cells with oval nuclei. In immunohistochemical studies, the tumor cells were positive with respect to c-kit, CD34, and vimentin, but negative with respect to smooth muscle actin and S-100 protein. There were 15-16 mitoses per 50 high-power fields (HPFs), and the ki-67 antigen (MIB-1) index was 25.5% in the most active areas, which also indicated malignancy. The final pathological diagnosis of this tumor was malignant GIST. The patient was found to have hepatic metastasis 27 months after the surgery, and he subsequently received a hepatic subsegmentectomy. To our knowledge, there are very few reports concerning the growth rate of GISTs. Computed tomographic volumetry is useful for the follow-up of small or irregularly shaped gastric submucosal tumors, and for making decisions regarding surgical intervention.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
3/4. Coexistence of hepatocellular carcinoma and gastrointestinal stromal tumor: a case report.Malignant gastrointestinal stromal tumors (GIST) are rare mesenchymal tumors originating from the wall of the gastrointestinal tract. Their coexistence with other tumors originating from other germ layers is unique. We have reported a case of a 63-year-old GIST patient presenting as an epigastric mass associated with hepatic tumor. Histologically, the mesenteric tumor was composed of spindle cells showing both neural and smooth muscle differentiation. Immunohistochemical examination showed positive staining for CD117, vimentin, S-100, and SMA, while CD34 antigen was negative. The hepatic tumor was diagnosed as hepatocellular carcinoma (HCC). To the best of our knowledge, this is the first case of GIST and HCC coexistence. The rarity of the case, however, should not lead to ignoring such a possibility in differential diagnosis.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
4/4. Gastrointestinal stromal tumor of the prostate: a case report and literature review.We report a case of gastrointestinal stromal tumor (GIST) of the prostate in a 75-year-old man with dysuria and urinary retention. digital rectal examination revealed a markedly enlarged prostate. The serum level of prostate-specific antigen was 0.2 ng/dL. Imaging studies showed an expanded prostate, measuring 6.7 x 5.6 x 5.5 cm, with heterogeneity in contrast enhancement. No metastatic disease was found. The pathologic diagnosis of prostatic GIST was made based on characteristic morphological features, immunoprofiles, and molecular analysis. The possibility of secondary involvement by a rectal GIST was excluded by radiological and intraoperative findings. To our knowledge, this is the second case of a primary GIST of the prostate reported in the literature.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |