Humans ; Mastocytosis, Systemic ; Retrospective Studies ; Proto-Oncogene Proteins c-kit

C-kit-negative gastrointestinal stromal tumors (GISTs) are uncommon, and there have been few reports about the diagnosis and treatment of c-kit-negative GISTs in the stomach. We report the case of a patient who was diagnosed with a huge and atypical GIST in the stomach. The GIST was completely resected and finally diagnosed as c-kit-negative GIST based on immunohistochemical staining of tumor cells, which were negative for CD117 and CD34 and positive for Discovered on GIST-1 (DOG1). C-kit-negative GISTs could be treated by complete resection and/or imatinib, which is the same treatment for c-kit-positive GISTs.
Diagnosis ; Gastrointestinal Stromal Tumors* ; Humans ; Proto-Oncogene Proteins c-kit ; Stomach* ; Imatinib Mesylate

PURPOSE: Phyllodes tumors (PTs) of the breast have been classified as benign, borderline, or malignant based on their histopathologic features. However, predicting clinical behavior based on these features has proven to be difficult given that local recurrence occurs in both benign and malignant PTs. Recurrence has been shown to mirror the histologic pattern of the primary tumor or to show dedifferentiation. The aim of this study was to assess the value of the histopathologic parameters, expression or mutation of c-Kit and platelet derived growth factor receptor alpha (PDGFRA) in predicting tumor recurrence. METHODS: Representative areas from 39 benign, 16 borderline, and 12 malignant PTs were selected for construction of tissue microarrays. Immunohistochemical analyses for p53, Ki-67, c-Kit, and PDGFRA were performed and SSCP-PCR analysis was carried out to identify mutations in exons 9, 11, 13, and 17 of the c-Kit gene and exons 12 and 18 of the PDGFRA gene. Clinicopathologic features, including tumor recurrence and margin status, were also evaluated. RESULTS: Of the 67 PTs, 11 cases (16.4%) recurred from 3 to 92 months following initial diagnosis (4 benign, 2 borderline, and 5 malignant). One benign PT case recurred as a borderline tumor and two borderline PT cases recurred as malignancies. Three patients died of malignant PT. No mutations of the c-Kit or PDGFRA genes were found and there was no statistically significant association of either p53 or p16 immunostaining with recurrent disease (p>0.05). However, histologic grade (p=0.033), margin status (p<0.001), Ki-67 (p=0.012), c-Kit (p=0.002), and PDGFRA (p=0.007) stromal immunopositivity were significantly correlated with recurrence. CONCLUSION: Even though positive or close margins were significantly associated with tumor recurrence, stromal c-Kit, PDGFRA positivity, and the Ki-67 index were useful for predicting recurrent PTs. Despite this, no c-Kit or PDGFRA mutations were found.
Breast ; Exons ; Humans ; Phyllodes Tumor ; Proto-Oncogene Proteins c-kit ; Receptors, Platelet-Derived Growth Factor ; Recurrence

To determine the effect of a recombinant lentivirus containing human stem cell leukemia (SCL) gene on the expression of c-kit protein in damaged interstitial cells of Cajal (ICC) under high glucose condition.
 Methods: After isolation of ICC, the cells were cultured for 24 hours until the cells were adherent. After identification by inverted microscope and immunofluorescence, ICC cells were divided into two groups: A control group and a high glucose group. The control group was added with a medium containing 5 mmol/L of glucose. The high glucose group was added with a medium containing 20 mmol/L of glucose. After 48 h of continuous cultivation, the high glucose group was divided into 3 subgroups: A blank group, an empty lentivirus group, and an experimental group. The blank group, the empty lentivirus group, and the experimental group were added a medium containing PBS solution, empty lentivirus, and a recombinant lentivirus containing the SCL gene with a glucose concentration of 5 mmol/L, respectively. The cultures were incubated for 24 and 48 h. The expression of c-kit protein in ICC in each group was detected by Western blot.
 Results: After 24 or 48 h, the expression of c-kit protein in ICC was significantly lower in the blank group and the lentivirus group than that in the control group, and the expression of c-kit protein in ICC was significantly higher in the experimental group than that in the blank group and the empty lentivirus group, but it was still lower than that in the control group (all P<0.05).
 Conclusion: The recombinant lentivirus of SCL gene can up-regulate the expression of c-kit protein in functionally impaired ICC under high glucose condition.
Glucose ; Humans ; Interstitial Cells of Cajal ; Lentivirus ; Leukemia, Myeloid, Acute ; Proto-Oncogene Proteins c-kit

OBJECTIVE: To study the value of flow cytometric scoring system in the diagnosis of myelodysplastic syndromes (MDS). METHODS: The phenotypes of erythroid and immature cells were analyzed retrospectively in 130 MDS patients, 19 healthy controls and 89 pathological controls, all of them were well clinically immunophenotyped. The 4-parameter scoring system reported in the literature was studied, including myeloblast-related cluster size, B-progenitor-related cluster size, lymphocyte to myeloblast CD45 ratio, and granulocyte to lymphocyte side scatter ratio. The two flow cytomatric parameters of the erythroid scoring system were analyzed, including CD36 coefficient of variation (CV) and CD71CV. According to our previous study, the percentage of CD117CD105 myeloid progenitor cells and the proportion of CD105 cells in CD117 cells were selected to establish a two-parameter scoring system, and compared with the four-parameter scoring system and the erythroid scoring system. RESULTS: The sensitivity of the four-parameter scoring system and the erythroid scoring system for the diagnosis of low-risk MDS was 43.5% and 63.0%, and the specificity was 87.0% and 63.9%, respectively. After combining the two scoring systems, the sensitivity to diagnose low-risk MDS was 73.9% and the specificity was 62.0%. The sensitivity of the two-parameter scoring system for the diagnosis of low-risk MDS was 76.1% with a specificity of 81.5%. Combined with the four-parameter scoring system, the sensitivity was increased to 78.3%, but the specificity was reduced to 71.3%. After combining with the erythroid scoring system, the sensitivity reached 87.0%, but the specificity was reduced to 54.6%. CONCLUSION Using the two-parameter scoring system alone can achieve great sensitivity and specificity in the diagnosis of low risk MDS.
Endoglin ; Flow Cytometry ; Humans ; Immunophenotyping ; Myelodysplastic Syndromes ; diagnosis ; Proto-Oncogene Proteins c-kit ; Retrospective Studies

OBJECTIVETo investigate the incidence of karyotypes and gene mutations for elder acute myeloid leukemia and to explore the relationship between each other.

METHODSClinical data and bone marrow samples of elder AML patients were collected. Karyotype and gene mutation (FLT3, NPM1, C-Kit, CEBPα, DNMT3A) test were performed, characteristics of karyotypes and gene mutations were analysed.

RESULTSThe incidence of better risk karyotype was 16.6%, in which the incidences of t(15;17), t(8;21) and inv (16)/t(16;16) were 3.90%, 10.73%, and 1.95% respectively; the incidence of intermediate risk karyotype was 72.2%, in which the incidence of normal karyotype was 57.86%; the incidence of poor risk karyotype was 11.20%, in which the incidence of of MLL/11q23, complex karyotype and monosomal karyotype were 1.95%, 6.34%, 5.85% respectively; the incidences of FLT3, NPM1, C-Kit, CEBPα, DNMT3A mutation were 12.57%, 22.06%, 2.16%, 14.71%, 15.71% respectively. Compared with patients older than 60 years, patients with age of 55-60 years were with less complex karyotype (1.09% vs 10.62%)(P=0.003) and monosomal karyotype (2.17% vs 8.85%)(P=0.032), and more t(8;21)(17.39% vs 5.31%)(P=0.008) and inv (16)/t(16;16)(4.35% vs 0.00%)(P=0.045).

CONCLUSIONFor older AML patients, great difference in the distribution of karyotyes was found between the patients older than 60 years and patients with age of 55-60 years, while no such characteristics was found for gene mutations. Good elucidation of karyotypes and gene mutations are key for the treatment of older acute myeloid leukemia patients.

OBJECTIVETo investigate the morphological features, immunohistochemical speciality of the gastrointestinal stromal tumors (GISTs), and its histogenesis as well.

METHODSThe morphologic characteristics of GISTs were studied in 65 cases using light microscopy and 17 cases by electron microscopy. The expression of c-kit (CD117), CD34, vimentin, SMA, actin, desmin, S-100 and MBP were detected in all the cases with EnVision trade mark staining.

RESULTSAmong 65 cases of GISTs, 46 were spindle cell type, 6 epithelioid cell type and 13 mixture type, equivalent to 85.5% (65 of 76) of all of the mesenchymal tumors of gastrointestinal tract admitted in the same period. The epithelioid cell type tumors composed of mainly the epithelioid cells, predominantly short spindle, oval or round in pattern, with an overall eosinophilic cytoplasm by hematoxylin-eosin stain. Focal cytoplasmic vacuolization was often seen. Sometimes signet-ring like cells and cells with a clear cytoplasm were seen in the epithelioid stromal tumor. The tumor cells arranged in interlacing fascicles forming whorls or sometimes cell clusters. Electronic microscopy showed the presence of interdigitating cell processes, in some areas, synapse-like structure and numerous desmosome-like junctions as well as a few gap junctions and small round neurosecretory granules. There were also abundant intermediate filaments and thin filaments of actin-type with longitudinal condensations (dense bodies). All of the 65 stromal tumors were strongly positive for vimentin (100%), 61 out of 65 tumors positive for CD117 (c-kit) (93.8%) and 51 out of 65 positive for CD34 (78.5%). Some cases also expressed SMA, actin, S-100 and MBP.

CONCLUSIONSGISTs were the most frequent mesenchymal tumor seen in the gastrointestinal tract. Under light microscope, the morphology of stromal tumors looks sometimes like a leiomyoma and Schwannoma. The application of immunohistochemical markers (particularly CD117 and CD34) and ultrastructural study are considered necessary for the differential diagnosis. GISTs may originate from the pluripotential precursor cells like the interstitial cells of Cajal.

Cell Membrane ; metabolism ; Gastrointestinal Stromal Tumors ; diagnosis ; metabolism ; Humans ; Immunohistochemistry ; Proto-Oncogene Proteins c-kit ; analysis

BACKGROUNDHuman piebaldism is a rare autosomal dominant condition characterized by congenital white forelock and depigmented patches of skin, typically on the forehead, anterior trunk and extremities. Mutations in the KIT gene have been proposed to be responsible for the underlying changes in this disorder. The aim of this study was to identify gene mutation in a Chinese family with piebaldism.

METHODSA Chinese family with piebaldism presenting with white forelock and large depigmented skin macules on the abdomen, arms and legs was collected. DNA was isolated from peripheral blood of the family members. The encoding exons with flanking intron regions of the KIT gene were analyzed by polymerase chain reactions (PCR) and direct DNA sequencing. Besides, DNA extracted from 100 ethnically matched population individuals was as controls.

RESULTSA heterozygous missense mutation c.2590T > C was identified in the patients of the family. This mutation converted a serine residue to proline (p.Ser864Pro). The mutation was not found in their unaffected family members or normal controls.

CONCLUSIONA novel missense mutation c.2590 T > C was found and it might play a significant role in the piebaldism phenotype in the family.

Gastrointestinal Stromal Tumors/pathology* ; Humans ; Proto-Oncogene Proteins c-kit/genetics*