1.Clear cell chondrosarcoma with secondary aneurysmal bone cyst changes.
Timothy TAY ; Steven Bak Siew WONG ; Kesavan so SITTAMPALAM ; Denny Tjiauw Tjoen LIE
Singapore medical journal 2014;55(3):e49-51
Clear cell chondrosarcoma is a rare cartilaginous tumour of low-grade malignancy. Although it has a characteristic histological appearance, its radiological features and clinical presentation often mimic a benign lesion. Herein, we describe the case of a patient with a clear cell chondrosarcoma of the right proximal femur that had an atypical appearance of chronic avascular necrosis on initial plain radiographs, which made preoperative diagnosis a challenge. In addition, the tumour also had extensive areas of aneurysmal bone cyst-like changes, which is not only a rare histologic phenomenon in clear cell chondrosarcoma, but also a confounding factor in the interpretation of the radiologic findings.
Adult
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Bone Cysts, Aneurysmal
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complications
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diagnostic imaging
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Bone Neoplasms
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complications
;
diagnostic imaging
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Chondrosarcoma
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complications
;
diagnostic imaging
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Female
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Femur
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diagnostic imaging
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pathology
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Hip
;
pathology
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Humans
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Magnetic Resonance Imaging
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Necrosis
;
pathology
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Osteoarthritis
;
diagnostic imaging
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Radiography
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Whole Body Imaging
2.Comparison of the sensitivity and specificity of p16/Ki-67 dual staining and HPV DNA testing of abnormal cervical cytology in the detection of histology proven cervical intraepithelial neoplasia grade 2 and above (CIN 2+)
Timothy Kwang Yong Tay ; Kah Ling Lim Bsc ; Maryam Hazly HILMY ; Aye Aye THIKE ; Sang Thoe GOH ; Lee Hong SONG ; Jacqueline Siok Gek Hwang ; Sangeeta MANTOO
The Malaysian Journal of Pathology 2017;39(3):257-265
Introduction: Human papillomavirus (HPV) testing is used as a means of triaging cervico-vaginalsmears with low grade squamous abnormalities or as part of co-testing with cytology. While HPVtesting has a high sensitivity, it has a low specificity in detecting cervical intraepithelial neoplasiagrade 2 and above (CIN 2+) leading to unnecessary colposcopy referrals. We investigate the accuracyof the p16/Ki-67 dual immunocytochemical stain in determining the presence of CIN 2+ lesions onhistology and its potential as a superior biomarker for triage. Methods: Liquid based cervico-vaginalcytology specimens with squamous abnormalities and corresponding histology from 97 women withsubsequent colposcopy and biopsy were included. The specimens were then subjected to the dual stainand Roche Cobas 4800 multiplex real time PCR HPV DNA testing. The sensitivity and specificity ofthe dual stain and HPV testing were calculated using CIN 2+ on histology as a reference standard.Results: The sensitivity and specificity of the dual stain in detecting histology proven CIN 2+ was93.7% and 76.5% while HPV testing was 85.7% and 14.7% respectively. Of the 44 women withASCUS or LSIL on cytology, the dual stain also reduced the number of unnecessary colposcopyreferrals from 27 to 7 when used as a triage marker compared to HPV testing. Conclusion: p16/Ki-67dual stain was more sensitive and specific than HPV testing in determining the presence of CIN 2+on histology. It could triage low grade cervico-vaginal specimens more effectively and potentiallyhelp women avoid unnecessary colposcopies. Future studies are needed to further evaluate its rolein cervical cancer screening programmes.
4.Biomechanical Study of Cervical Endplate Removal on Subsidence and Migration in Multilevel Anterior Cervical Discectomy and Fusion
Maohua LIN ; Rudy PAUL ; Stephen Z. SHAPIRO ; James DOULGERIS ; Timothy E. O’CONNOR ; Chi-Tay TSAI ; Frank D. VRIONIS
Asian Spine Journal 2022;16(5):615-624
Methods:
Model 1 (M1) was an intact C2C6 model with a 0.5 mm endplate. In model 2 (M2), a cage was implanted after removal of the C4–C5 and C5–C6 discs with preservation of the osseous endplate. In model 3 (M3), 1 mm of the osseous endplate was removed at the upper endplate. Model 4 (M4) resembles M3, except that 3 mm of the osseous endplate was removed.
Results:
The range of motion (ROM) at C2C6 in the M2–M4 models was reduced by at least 9º compared to the M1 model. The von Mises stress results in the C2C3 and C3C4 interbody discs were significantly smaller in the M1 model and slightly increased in the M2–M3 and M3–M4 models. Migration and subsidence decreased from the M2–M3 model, whereas further endplate removal increased the migration and subsidence as shown in the transition from M3 to M4.
Conclusions
The M3 model had the least subsidence and migration. The ROM was higher in the M3 model than the M2 and M4 models. Endplate preparation created small stress differences in the healthy intervertebral discs above the ACDF site. A 1 mm embedding depth created the best balance of mechanical strength and contact area, resulting in the most favorable stability of the construct.
5.A Review of Finite Element Modeling for Anterior Cervical Discectomy and Fusion
Maohua LIN ; Rudy PAUL ; Utpal Kanti DHAR ; James DOULGERIS ; Timothy E. O’CONNOR ; Chi-Tay TSAI ; Frank D. VRIONIS
Asian Spine Journal 2023;17(5):949-963
The cervical spine poses many complex challenges that require complex solutions. Anterior cervical discectomy and fusion (ACDF) has been one such technique often employed to address such issues. In order to address the problems with ACDF and assess the modifications that have been made to the technique over time, finite element analyses (FEA) have proven to be an effective tool. The variations of cervical spine FEA models that have been produced over the past couple of decades, particularly more recent representations of more complex geometries, have not yet been identified and characterized in any literature. Our objective was to present material property models and cervical spine models for various simulation purposes. The outlining and refinement of the FEA process will yield more reliable outcomes and provide a stable basis for the modeling protocols of the cervical spine.