We recently identified a stage in fetal ontogeny (NK1.1+/CD117+) that defines committed progenitors for T and NK lymphocytes. These cells are found in the fetal thymus as early as day 13 of gestation, but are absent in the fetal liver. Nonetheless, multipotent precursors derived from both the fetal thymus and fetal liver are capable of rapidly differentiating to the NK1.1+ stage upon transfer i...

Myelomatous plasma cells show a high heterogeneity both in their immunophenotypic characteristics as well as in their cytogenetic features. Thus far, no extensive studies have been carried out to explore whether such antigenic diversity is associated with specific genetic characteristics. We have investigated the relationship between the immunophenotypic profile at plasma cell and both their DN...

Gastrointestinal stromal tumour (GIST) is a rare but most common mesenchymal tumour in the gastrointestinal tract. Although GIST research has been carried out extensively worldwide, it has yet to be studied in Malaysia. To establish the immunohistochemical expression pattern of CD117 (c-KIT), CD34, S-100 and Desmin, the incidence of c-KIT and PDGFRA genes mutation in GISTs, and correlate it wit...

BACKGROUND The immunohistochemical hallmarks of gastrointestinal stromal tumors (GISTs) are positivity for CD117 (c-kit) and CD34; however, CD117 is not specific for GISTs, and the list of CD117+ tumors/tissues is increasing. Also, MDM2 is known to be amplified in several types of mesenchymal tumors, including liposarcoma. METHODS We report a spindle cell sarcoma arising in the mediastinum th...

OBJECTIVES The aims of this study were to evaluate the predictive role of morphology in a series of breast phyllodes tumours (PTs) in Asian women, and to determine the utility of immunohistochemical expression of p53 and CD117 in the stromal component. MATERIALS AND METHODS Breast PTs, diagnosed between January 1992 and December 2002 at the Department of Pathology, Singapore General Hospital,...

During heart morphogenesis, epicardial cells undergo epithelial-mesenchymal transition giving origin to a population of epicardially derived cells that play a crucial role in the development of most cardiac cell lineages. Considering the hypothesis that epithelial-mesenchymal transition of epicardial mesothelium can generate cardiac primitive cells in the adult heart, we have examined in vivo a...

Background Mediastinum harbors a mixed bag of neoplastic lesions with varied therapeutic and prognostic implications. Distinguishing pulmonary squamous cell carcinoma from thymic carcinoma is a challenging task owing to rather nonspecific clinicoradiological features and a considerable overlap in histomorphological features. Thus, we evaluated the diagnostic utility of cluster of differentiatio...

A total of 97 acute promyelocytic leukemia (APL) patients with adequate flow cytometry (FC) data, bone marrow aspirates and presence of t(15;17)/PML-RARA by cytogenetics and/or FISH studies were analyzed for immunophenotypic pattern. Leukemic cells had the following phenotype: CD11b-, CD11c-, CD13+, CD33+, CD45+, CD64+/-, CD117+, and HLA-DR-. A subset of cases showed also an expression of CD2, ...

The CD117 protein is a tyrosine-kinase receptor encoded by the c-kit gene that frequently bears activating mutations in gastrointestinal tumors. Conflicting findings regarding CD117 expression in other stromal tumors, including phyllodes tumors (PTs), have been reported in the literature. The purpose of this study was to evaluate c-kit expression in the stroma and epithelia of fibroepithelial b...

Ras guanine nucleotide-releasing protein-4 (RasGRP4) is an evolutionarily conserved calcium-regulated, guanine nucleotide exchange factor and diacylglycerol/phorbol ester receptor. While an important intracellular signaling protein for CD117+ mast cells (MCs), its roles in other immune cells is less clear. In this study, we identified a subset of in vivo-differentiated splenic CD117+ dendritic ...