Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P10721 (c-kit)
 6,575 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gastrointestinal stromal tumour (GIST) has been immunohistochemically defined as the tumour lacking differentiation towards either leiomyomatous tumour or schwannoma. We report a 75-year-old man who underwent an abdominoperineal resection of a large submucosal tumour of the rectum. The excised specimen was revealed to be an elastic soft tumour, 8 x 7 x 6 cm in size, which histologically consisted of spindle-shaped cells without nuclear atypia. The mitotic count was fewer than 2 per 10 high-power fields. The tumour cells were positive for staining of CD34 and c-kit protein, while the lesions were negative for alpha-smooth muscle actin, HHF-35, neuron-specific enolase, and S-100 protein. The diagnosis of GIST was confirmed by immunohistochemical examination of the tumour. From these findings, the present case is thought to be potentially malignant, and a long-term follow-up observation is needed for the case.
 ...
PMID:Gastrointestinal stromal tumour of the rectum. 1129 50

42 gastrointestinal mesenchymal tumors are analyzed by the authors with characterization of immunohistochemistry and DNA study. Out of 42 tumors, 29 GIST 3 leiomyoma, 4 leiomyosarcoma, 3 benign schwannoma, 1 soliter fibrous tumor, 1 inflammatory myofibroblastic tumor and 1 benign haemangiopericytoma were found. All 29 GIST but two could be characterized by c-kit (CD-117) and CD-34 positivity independently weather they displayed focal neurogenic and/or myogenic immunomarkers. In GIST group, 10 cases were benign, 6 borderline and 13 malignant. All benign cases were euploid by DNA study, the malignant tumours were highly aneuploid. Concerning the borderline GIST group by morphology, the aneuploid DNA content may speak for malignant biological behavior, and the diploid DNA content in low grade malignant GIST by morphology may speak for better outcome in the malignant group. There is a discussion about the nomenclature of this morphological group, about the role of the c-kit gene and the necessity of the immunohistochemistry and DNA content determination.
 ...
PMID:[Gastrointestinal stromal tumors. Observations on the basis of 29 cases]. 1177 55

We analyzed the clinicopathological features of 12 gastrointestinal (GI) schwannomas and compared them with those of 37 GI stromal tumors (GISTs) and 15 leiomyomas. Grossly, the schwannomas showed rubbery to firm, yellow-white to tan, glistening, and often trabeculated cut surfaces, resembling soft tissue schwannomas. The GISTs were firm to soft or fish-flesh tan, gray-pink, or variegated tumors with a degenerative change, and the leimyomas resembled typical uterine leiomyomas. Histologically, GI schwannomas were moderately cellular tumors with focal significant nuclear pleomorphism and rare mitotic figures. A characteristic peripheral lymphoid cuff was observed in all cases, but was indistinct in two cases. The GISTs were highly cellular spindle cell, epithelioid or, occasionally, pleomorphic tumors with basophilic appearance. Leiomyomas were paucicellular tumors with eosinophilic appearance. Immunohistochemically, schwannomas were S-100 protein- and glial fibrillary acidic protein (GFAP)-positive, but were negative for c-kit, CD34, and smooth muscle actin (SMA). GISTs were all c-kit- and/or CD34-positive, but GFAP-negative. Leiomyomas were SMA-positive and were negative for c-kit, CD34, S-100 protein, and GFAP. The mean Ki-67 index of schwannoma was 0.7, and those of GIST and leiomyoma were 5.9 and 0.3, respectively. The patients with schwannomas and leiomyomas had a favorable outcome, whereas 12 patients with GISTs showed progression and died of disease. The separation of GISTs from schwannomas is clinically important because the former group has a high risk of malignant behavior. GI schwannomas differed from the conventional soft tissue schwannomas in that they had peripheral lymphoid cuffs, lacked fibrous capsule and vascular hyalinization, and rarely showed degenerative changes. GI schwannomas, however, resembled soft tissue schwannomas in many aspects, and the clinical, gross, histological, and immunohistochemical features were different from those of GISTs and leiomyomas.
 ...
PMID:Schwannomas of the gastrointestinal tract: clinicopathological features of 12 cases including a case of esophageal tumor compared with those of gastrointestinal stromal tumors and leiomyomas of the gastrointestinal tract. 1244 Jul 83

Plexiform schwannoma is a benign peripheral nerve sheath tumor composed exclusively of schwann cells arranged in a plexiform pattern. Most plexiform schwannomas are skin tumors and there has been only one case report of this tumor originating in the colon. We describe herein the first known case of plexiform schwannoma of the small intestine occurring without any relationship to schwannomatosis or neurofibromatosis. A 57-year-old man presented with a short history of abdominal pain, vomiting, and bloody stool after each meal. Jejunography demonstrated multiple nodular tumors in the small intestine. We resected the small intestine laparoscopically. The tumors consisted of multiple white nodules in the submucosal and subserosal layers. Microscopic examination revealed that each tumor was composed mainly of Antony A tissue, compatible with conventional schwannoma. Immunohistochemically, the tumors were positive for S-100, vimentin, and neuron-specific enolase, and negative for HHF35, Alpha-SMA, and c-kit. No evidence of recurrence has been found in 38 months of follow-up.
 ...
PMID:Plexiform schwannoma of the small intestine: report of a case. 1466 89

We studied 25 cases of schwannoma and 42 cases of neurofibroma immunohistochemically with antibodies to calretinin and S-100 protein to explore the potential usefulness of calretinin in differentiating schwannomas from neurofibromas. Of 25 schwannomas, 24 (96%) showed moderate to strong staining for calretinin, with the extent of staining ranging from focal to diffuse. In contrast, only 3 (7%) of 42 neurofibromas displayed focal weak to moderate staining with calretinin. All 42 cases of neurofibromas and all 25 cases of schwannomas showed diffuse moderate to strong staining with S-100 protein. Calretinin also labeled mast cells, whose presence was confirmed further by staining for c-kit, which commonly was present in both tumor types in a scattered individual cell pattern easily differentiated from the clustered pattern of neoplastic spindle cells. Taken together, these results indicate that calretinin is detected in almost all schwannomas and in only a small percentage of neurofibromas, suggesting it is a useful marker for differentiating schwannomas from neurofibromas. Although mast cells present in these 2 neoplasms also react with calretinin, the pattern of staining can be distinguished easily from that of neoplastic cells.
 ...
PMID:Immunohistochemical staining for calretinin is useful for differentiating schwannomas from neurofibromas. 1548 53

Pigmented neurofibroma (PNF) is a rare variant of neurofibroma showing melanin production. To clarify the clinicopathologic features of PNF and to characterize melanogenesis in PNF, 12 cases of PNF were examined in comparison with schwannoma (SCH, n = 16) and neurofibroma (NF, n = 26). The PNF patients were all Japanese including 7 men and 5 women, and patient age ranged from 11 to 71 years (median, 23.5 years). They showed strong a predisposition for neurofibromatosis type 1. Their tumor size was large, and tumors arose from various sites of skin. Histologically, clusters of epithelioid, dendritic, and spindle melanin-producing cells with faint pigmentation had a tendency to locate in deep dermis and subcutis, which seems to be a characteristic pattern of melanogenesis. There was a transition between melanin-producing cells and Schwann cells. Immunohistochemical examination included known melanogenic markers, microphthalmia-associated transcription factor (MITF), which is a key regulator of melanogenesis, and 2 tyrosine kinase receptors, c-Met and c-Kit, which regulate the development of melanocytes. In PNF, melanin-producing cells were S100 (+), MITF (+), Melan-A (+), tyrosinase (+/-), HMB45 (+/-), c-Met (+), and c-Kit (-). Schwann cells were S100 (+), MITF (-), Melan-A (-), tyrosinase (-), HMB45 (-), c-Met (-), and c-Kit (-), and intermediate spindle cells were S100 (+), MITF (+), Melan-A (+), tyrosinase (-), HMB45 (-), c-Met (+), and c-Kit (-). When compared with SCH and NF, MITF was weakly expressed in a part of tumor cells of SCH, whereas no definite staining was found in NF. c-Met expression was very weak in a scattered manner in SCH (10/15 cases) and NF (10/26 cases). These results suggest that PNF is a unique tumor that shows differentiation toward mature melanin production, but ability of melanin synthesis seems to be impaired. There may be a close relationship between up-regulated MITF and c-Met and the peculiar melanogenic nature of PNF, and both of these are useful diagnostic tools for distinguishing PNFs with less melanin production from NFs.
 ...
PMID:Pigmented neurofibroma: review of Japanese patients with an analysis of melanogenesis demonstrating coexpression of c-met protooncogene and microphthalmia-associated transcription factor. 1611 3

We report a case of esophageal schwannoma in a 46-year-old woman who presented with rapidly progressive dyspnea and dysphagia. Chest computed tomography showed a large mediastinal mass, which was extrinsically compressing the trachea, widely adjacent to the upper thoracic esophagus. We performed an axillary right thoracotomy to enucleate the tumor, which was located in the esophageal muscle layer. A definite diagnosis of esophageal schwannoma was made from the pathologic findings, which included positive immunohistochemical staining for S-100 protein and negative staining for c-kit and CD34.
 ...
PMID:Esophageal schwannoma: report of a case. 1752 70

Schwannomas, although benign, can be fatal or give rise to significant morbidity due to an unpredictable growth rate. They can reoccur after surgery or radiation, current treatments each with significant inherent risks. These risks are further amplified in neurofibromatosis type 2 (NF2), a germ line predisposition syndrome characterized by multiple schwannomas, underlying the need for biological targeted therapies. Gleevec (STI571, imatinib mesylate), in addition to the bcr-abl oncogene in chronic myelogenous leukemia, inhibits c-kit and platelet-derived growth factor receptor (PDGFR) signaling, thereby expanding its use to several malignant and benign human diseases. In the present study, we show that human sporadic and NF2-associated schwannomas have increased expression along with activation of PDGFR-alpha, PDGFR-beta, and c-kit receptors, compared with normal or traumatic nerve. Using the human NF2-null HEI-193 schwannoma cell line, Gleevec inhibited schwannoma viability, proliferation, and anchorage-independent growth, as well as induced apoptosis in a dose-dependent manner (IC(50) 5-10 micromol/L). These antitumorigenic effects were correlated to inhibition of PDGFR-alpha, PDGFR-beta, and c-kit activation/phosphorylation and major downstream signaling pathways. Lack of robust xenograft or transgenic models of schwannomas prevents extension of these studies in vivo. However, the established long track record and tolerable toxicity of Gleevec already in clinical use and our preclinical data lead us to propose that Gleevec should be evaluated in human schwannomas with shown progressive growth.
 ...
PMID:Human schwannomas express activated platelet-derived growth factor receptors and c-kit and are growth inhibited by Gleevec (Imatinib Mesylate). 1950 33

During postslaughter inspection of a 4-year-old male dromedary camel (Camelus dromedarius), numerous small nodules to large masses up to 4 cm in diameter were found on the serosal surfaces of forestomachs, large intestines, mesentery, liver, and spleen. Grossly, the masses were discrete, round, smooth, and white to gray that bulged from the serosal layer. Cut surfaces of the masses were discrete, round, white, and relatively homogeneous without any necrotic foci. Histopathologically, the masses were encapsulated and composed of a mixture of round and spindle-shaped cells in loose whorls of neoplastic cells with small elongated hyperchromatic wavy nuclei and a small amount of pale eosinophilic, poorly defined cytoplasm. Masson's trichrome staining showed mild amounts of collagen fibers forming an irregular, loose stroma. In immunohistochemistry, immunoreactivity for the Schwann cell marker (S100) was diffusely positive in the neoplastic cells. The immunoreactivity for CK, c-kit, and CD34 were negative. Ultrastructural examination confirmed the tumor was entirely formed of neoplastic Schwann cells. On the basis of the histopathological, immunohistochemical, and ultrastructural findings, the tumors were diagnosed as multicentric fibromyxoid peripheral nerve sheath tumor (multicentric schwannoma). This tumor has not been previously recorded in camel worldwide.
 ...
PMID:Multicentric fibromyxoid peripheral nerve sheath tumor (multicentric schwannoma) in a dromedary camel (Camelus dromedarius): morphopathological, immunohistochemical, and electron microscopic studies. 2080 21

We report a schwannoma of the gallbladder in a 58-year-old man who was diagnosed as cholecystolithiasis. He presented with recurrent episodes of abdominal pain in the right upper quadrant. The abdominal computed tomography scan and ultrasonography revealed stones about 15 mm in diameter in the gallbladder. Under the diagnosis of cholecystolithiasis, laparoscopic cholecystectomy was performed. The resected specimen showed chronic cholecystitis and no suspicion of neoplasm. Pathological examination revealed that the tumor consist of spindle cells without atypical appearance at small area of fundus. Immunohistologically, tumor cells were positive for S-100 protein and negative for alpha-SMA and c-kit, the lesion was diagnosed as schwannoma.
 ...
PMID:Schwannoma of the gallbladder: report of a case. 2148 54


1 2 3 Next >>