ABSTRACT
Purpose To study the clinicopathological, immunophynotypic features of pituicytoma and its rare ependymal variant with discussion of its diagnosis and differential diagnosis. Methods 7 cases of pituicytoma, including 6 conventional pituicytomas and 1 ependymal variant tumor, were evaluated by HE staining and immunohistochemistry, and the relevant literatures were reviewed. Results Microscopically, the tumors were composed of closely packed plump spindle cells arranged in short fascicle and storiform pattern in 6 conventional pituicytomas, and whorl and papillary architecture with obvious perivascular rosette formation in the ependymal variant tumor. Immunohistochemically, all tumor cells were diffuse positive for S-100 and TTF-1, but negative for IDH1 R132H, Olig-2, CD34, NF, Syn, CgA, and pituitary hormones. Ki-67 proliferation index was less than 2％ in all cases. GFAP and EMA were only focally positive in conventional pituicytomas, whereas GFAP was diffuse positive in ependymal variant tumor with EMA dot-like staining in more than half of tumor cells. Conclusion Pituicytoma is a rare low grade glioma derived from neurohypophysis. To study helps recognition of extending morphological spectrum of pituicytoma and its new variant, which is important for its differential diagnosis consideration and clinical therapy.
ABSTRACT
<p><b>BACKGROUND</b>We previously showed that nano-hydroxyapatite/carboxymethyl chitosan (n-Ha/CMCS) displayed excellent mechanical properties, good degradation rates and exceptional biocompatibility, with negligible toxicity. The aim of this study was to determine the effect of the same composite with vascular endothelial growth factor (VEGF)- transfected bone marrow stromal cells (BMSCs) in a rabbit radial defect model.</p><p><b>METHODS</b>The nano-hydroxyapatite was produced through co-precipitation. The n-HA/CMCS scaffold was produced by particle filtration and lyophilization followed by genipin crosslinking. Total RNA from rabbit bone was reverse-transcribed to synthesize VEGF165-pcDNA3.1 that was transfected into the BMSCs. The composite was implanted into a rabbit radial defect model, and the osteogenic activity examined by gross morphology, X-ray examination and hematoxylin and eosin (HE) staining.</p><p><b>RESULTS</b>The microstructure and mechanical property of the n-HA/CMCS scaffold resembled natural cancellous bone. Compared with glutaric dialdehyde crosslinked scaffolds, the genipin crosslinked scaffold was less toxic, and displayed a higher capacity to promote cell adhesion and proliferation. Spontaneous fluorescence of the composite permitted visualization of the composite-bone interface and the adhesion behavior of cells on the scaffold under laser scanning confocal microscopy. The scaffold with VEGF-transfected BMSCs bridged the bony defect and promoted healing, with most of the implanted material being replaced by natural bone over time with little residual implant. Using X-ray, we noted obvious callus formation and recanalization of the bone marrow cavity. Furthermore, HE stained sections showed new cortical bone formation.</p><p><b>CONCLUSIONS</b>The n-HA/CMCS scaffold composite with VEGF-trasnfected BMSCs is biocompatible, nontoxic, promotes the infiltration and formation of the microcirculation, and stimulates bone defect repair. Furthermore, the degradation rate of the composite matched that of growing bone. Overall, this composite material is potentially useful for bone defect repair.</p>