Minimally Invasive Approach for Excision of Dorsolumbar Spine Osteoid Osteomas using 3D Imaging and Stealth Navigation: A Report of Two Cases.

Advantages of three-dimensional (3D) computed tomography-based navigation system has recently been used for safe, accurate, reliable spinal tumour excision. This study presents two cases, a 33-year-old male and a 17-year-old male presented in the clinic with mid-back and low back ache, respectively with change in posture. Radiology suggested an osteoid osteoma. Accurate localisation and complete extirpation of the lesion were performed using a translaminar approach with O-arm Navigation. After follow-up of one year, both did not complain of back pain or radiation, scoliosis had improved in both cases and their VAS was 0 and ODI was 0%. 3D navigation with the O-arm system provided an easy and accurate localisation of the lesion, reducing the risk of instability subsequently and avoiding instrumented stabilisation. This technique also provided for histopathological confirmation of the diagnosis.

Actual Proliferating Index and p53 protein expression as prognostic marker in odontogenic cysts.

BACKGROUND: The purpose of this study was to evaluate the biological aggressiveness of odontogenic keratocyst/keratocystic odontogenic tumour (KCOT), radicular cyst (RC) and dentigerous cyst (DC) by observing the actual proliferative activity of epithelium, and p53 protein expression. METHODS: The actual proliferative activity was measured by Ki-67 Labelling Index and argyrophilic nucleolar organizing regions (AgNOR) count per nucleus. The p53 protein expression was also evaluated. RESULTS: Ki-67 positive cells were observed higher in suprabasal cell layers of KCOT with uniform distribution, a few of them were predominantly observed in basal cell layer in RC and DC. The AgNOR count was significantly higher in suprabasal cell layers of KCOT. The actual proliferative activity was noted to be higher in suprabasal cell layers of KCOT. The p53 immunolabelling was dense and scattered in basal and suprabasal cell layers in KCOT. The weakly stained p53 positive cells were observed diffusely distributed in KCOT, whereas they were mainly seen in basal cell layer of RC and DC. CONCLUSION: The quantitative and qualitative differences of the proliferative activity and the p53 protein expression in sporadic KCOT may be associated with intrinsic growth potential that could play a role in its development and explain locally aggressive biological behaviour. AgNOR count and p53 protein detection in odontogenic lesions can be of great consequence to predict the biological behaviour and prognosis.