Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0003615 (appendicitis)
 4,439 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mesenchymal tumors of the appendix are very rare, and specific stromal tumors (i.e., gastrointestinal stromal tumors, GISTs) have not been reported in this location to date. Four GISTs were identified in the review of primary mesenchymal tumors of the appendix from the files of the Armed Forces Institute of Pathology from 1970 to 1998. There were also one benign schwannoma, one diffuse neurofibroma with neurofibromatosis 1, one leiomyosarcoma in a child with HIV infection, and one inflammatory fibroid polyp. The four appendiceal GISTs occurred in adult males 56-72 years of age (mean 63 years). Two tumors occurred in patients who had surgery for appendicitis-like symptoms: one was an incidental finding during surgery for a malignant gastric epithelioid GIST and one was an incidental autopsy finding. Only one of the two appendices operated for symptoms had acute inflammation, and a polypoid GIST projected outward from the proximal part of appendix. Three tumors were partially obliterating nodules, eccentrically expanding the appendiceal wall. All four were spindle cell tumors, and three of them contained extracellular collagen globules (skeinoid fibers); none had atypia or mitotic activity (<1/50 high power fields). Immunohistochemically, two tumors studied were positive for CD117 (KIT), and two were positive for CD34. The tumors were negative for alpha-smooth muscle actin and S-100 protein. Follow-up revealed death from cardiovascular disease in one case (4 years after appendectomy) and liver failure because of malignant gastric epithelioid GIST metastatic to liver in another case 15 years after the appendectomy. This report documents the rare occurrence of CD117-positive GISTs as primary appendiceal tumors.
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PMID:Gastrointestinal stromal tumors in the appendix: a clinicopathologic and immunohistochemical study of four cases. 1622 28

Gastrointestinal stromal tumors (GIST) are rare in the vermiform appendix. Only 5 cases have been reported so far, all being 14 mm or less, and they have yet not been investigated at the molecular level. Here, we report 2 appendiceal gastrointestinal stromal tumors in a 78-year-old woman and a 72-year-old man with a history of endometrial adenocarcinoma and urinary bladder carcinoma, respectively. The first patient had a history of pelvic irradiation. Both gastrointestinal stromal tumors were incidental findings at surgery for appendicitis-like symptoms and on follow-up for bladder carcinoma, respectively. Tumors were 5 and 25 mm and were located in the mid portion and the tip, respectively. The larger gastrointestinal stromal tumor was pedunculated. Both revealed a spindle cell histology with variable stromal hyalinization and occasional skeinoid fibers in 1 case. Immunohistochemistry showed reactivity for CD117 and CD34 and loss of p16 in both. Case 2 overexpressed the catalytic subunit of the human telomerase reverse transcriptase immunohistochemically. Molecular analysis of KIT revealed a missense mutation K558R in case 1 and an in-frame deletion I571_R588 in case 2, both in the juxtamembrane domain (exon 11). Comparative genomic hybridization was successful in case 2 (larger lesion) and revealed no chromosomal imbalance. We suggest that the molecular pathogenesis of appendiceal gastrointestinal stromal tumors beyond initiating KIT mutations might be different from their gastric and intestinal counterparts. The coincidence of loss of p16 and overexpression of human telomerase reverse transcriptase seems to be in contradiction to the small size, the benign nature, and the limited growth potential of appendiceal gastrointestinal stromal tumors.
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PMID:Gastrointestinal stromal tumors of the vermiform appendix: clinicopathologic, immunohistochemical, and molecular study of 2 cases with literature review. 1854 14

Gastrointestinal stromal tumors of the vermiform appendix are rare. To date, only 11 cases have been reported in the English literature. Here, we present a new case of appendiceal gastrointestinal stromal tumor associated with complete situs inversus. A 48-year-old man was operated on due to appendicitis-like symptoms. Laparotomy revealed a ruptured conglomerate tumor in the lower abdomen associated with extensive peritoneal adhesions. Histology showed a spindle cell gastrointestinal stromal tumor with prominent sclerosis and calcification without low mitotic activity. The tumor cells expressed strongly CD117 and CD34. The mutation analysis revealed a heterozygous deletion/insertion involving exon 11 of KIT (pK558_V559delNNins). Because the tumor was ruptured intraoperatively, a high risk was assigned according to the revised National Institute of Health criteria and adjuvant therapy with imatinib mesylate was recommended. The patient is currently alive without evidence of progression 27 months after surgery.
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PMID:A novel complex KIT mutation in a gastrointestinal stromal tumor of the vermiform appendix. 2308 35