Role Of Notch Ligands In The Pathogenesis Of Giant Cell Tumor Of Bone And Biological Behavior Assessment Of Giant Cell Tumor Of The Spine By Radiology

Notch ligands in the pathogenesis of giant cell tumor of bone:A preliminary studyObjective: The purpose of this study was to examine the expression of Notch ligands(Jagged1, Jagged2, DLL1, DLL3and DLL4) in both fresh and paraffin-embededspecimens of giant cell tumor of bone (GCTb). The aim was to explore the function ofNotch ligands in the pathogenesis of GCTb combining with our previous findings onNotch receptors.Materials and methods: Between January2010and June2012, twenty fresh GCTbsurgical samples were collected at our institution. The expressions of Notch ligands onmRNA and protein levels were analyzed by semi-quantitative reverse transcriptasepolymerase chain reaction (RT-PCR) and Western blot. The results were confirmed byimmunohistochemistry with serial sections in paraffin embedded GCTb sections.Results: Jagged1was expressed on both mRNA and protein levels with previousexpression in the cytoplasma of multinucleated giant cells in immunohistochemistry.DLL1was expressed on both mRNA and protein levels, and in immunohistochemistry itwas mainly expressed in the cytoplasma of multinucleated giant cells and also in somemononuclear stromal cells. DLL3was expressed on protein level with visible expressionin the cytoplasma of multinucleated giant cells in immunohistochemistry but notexpressed on mRNA level. DLL4was expressed on both mRNA and protein levels withexpression on both tumor vessels and membrane of multinucleated giant cells inimmunohistochemistry. Jagged2showed no expression on mRNA, protein orimmunohistochemical level.Conclusion: Notch receptors, ligands, and Notch signaling pathway may be involved in the pathogenesis of GCTb. DLL1might be involved in neoplastic osteoclast. Jagged1might be correlated with the malignancy of GCTb. The expression of DLL4raises itspotential in tumor vasculogenesis. Giant cell tumors of the mobile spine:characteristic imaging features and differential diagnosisObjective: The purpose is to investigate the characteristic imaging features of thegiant cell tumors (GCTs) of the mobile spine.Materials and methods: Thirty cases of GCTs occurring in the mobile spine undersurgical treatment between January1990and March2012at two institutions werereviewed. Images of X-ray (n=18), CT (n=24) and MR (n=21) before treatment wereevaluated retrospectively and independently by two experienced radiologists.Results: Five tumors were located in the cervical spine, fifteen tumors in the thoracicspine and ten tumors in the lumbar spine. The characteristic X-ray findings included anosteolytic and expansile lesion with a “soap bubble” or purely lytic appearance. Corticaldestruction was commonly seen. Margin sclerosis was demonstrated in two lesions. Nomineralized tumor matrix or periosteal reaction was appeared. CT findings were similarbut outlined the cortical alterations in a more accurate way. The.characteristic MRfindings included a well-defined and expansile mass with heterogeneous low-to iso-signal-intensity on T2-weighted images. Cystic areas were commonly seen in17cases.Five cases presented fluid-fluid levels, suggesting the development of secondaryaneurysmal bone cyst. The solid portion of the tumors was intensively enhanced with avery heterogeneous signal pattern after contrast-enhanced scan reflecting a high bloodsupply. Tumor involvement in the epidural space occurred in12cases, causing spinalcord and/or nerve root compression. Involvement of intervertebral discs and/or adjacentvertebraes appeared in two cases.Conclusions: The imaging characteristics for GCTb of the mobile spine are: osteolyticand expansile lesions; margin sclerosis on X-ray and CT without matrix calcification;low-to iso-signal-intensity on T2-weighted images on MRI caused by hemosiderindeposition, which is the most important basis for diagnosis; internal cystic componentsand fluid-fluid levels are relatively common. Differentiation of primary chordoma, giant cell tumor andschwannoma of the sacrum by CT and MRIObjective: The purpose of this study was to determine if characteristic imaging featurescan differentiate primary sacral chordoma (SC), sacral giant cell tumor (SGCT) and giantsacral schwannoma (GSS).Materials and methods: Between January2001and November2012,22patients withSC,19patients with SGCT and8patients with GSS were collected at our institution. Theclinical and imaging features of each tumor were reviewed retrospectively andindependently by two experienced musculoskeletal radiologists according to thefollowing categories: age and gender, tumor size, tumor location (upper or lower part ofsacrum; centrally or eccentrically located), morphology of bone residues (irregular andfuzzy, incomplete bony shell), signal intensities on MRI, morphology of cysticcomponent within tumors (multiple and small, central and large), bleeding, fluid-fluidlevels, presence of intralesional septations, growth pattern, preservation of intervertebraldiscs, involvement of adjacent muscles and sacroiliac joints, extension within the spinalcanal.Results: The mean ages of SC, SGCT and GSS were55.1±10.7,34.3±10.7and42.4±15.7years old, respectively. SCs were predominantly centrally located in the lowerpart (below S3) of sacrum (77.3%), while the majority of SGCTs (73.7%) and GSSs(87.5%) were eccentrically located and confined to the upper segments of sacrum (aboveS4). There were significant differences (P<0.01) in onset of age, location within sacrumand eccentricity among the three groups. Morphology of bone residues was alsosignificantly different (P<0.01) with an irregular and fuzzy shape observed in90.9%ofthe SCs and incomplete bony shell shape in78.9%of SGCTs. Intratumoral bleeding wasalso different among three groups. Irregular and linear septations were displayed in95.5%of SCs,15.8%of SGCTs and absent in GSSs, showing a significantly difference(P<0.01). Multiple and small cystic areas were mainly observed in SGCTs (73.7%), whilelarge and centrally located cystic areas were seen in all GSSs (100%). Small fluid-fluid levels were only detected in5SGCTs. The three groups of tumor also displayed adifferent growth pattern (P<0.01) with SGCTs expanded mainly inside the sacrum whileSCs and GSSs more often extended into the pelvic cavity. Involvement of sacroiliacjoints were observed in27.3%of SCs and68.4%of SGCTs and absent in GSSs;involvement of adjacent muscles was observed in81.8%of SCs and68.4%of SGCTsand absent in GSSs; showing significant differences (P<0.01). The tendency of ascendingextension within the sacral canal was only observed in50%of SCs. The presence ofresidual intervertebral discs showed significant difference between large and smalltumors (P<0.01), regardless of tumor type (P>0.01). No significant difference wasdisplayed in gender or tumor size among the three groups (P>0.01).Conclusion: Age, epicentre of the lesion (midline vs. eccentric and up per vs. lowersacral vertebra), bone residues, cysts, bleeding, septations, expanding pattern, musclesand sacroiliac joints involvement can be criteria for differential diagnosis among SC,SGCT and GSS. Fluid-fluid level is specific for SGCTs and ascending extension withinthe sacral canal for SCs. The preservation of intervertebral discs is related to tumor sizerather than tumor type.