Study of Morphological Factors Determining Aggressive Local Spreading of Osteal Giant Cell Tumors

Introduction Osteal giant cell tumor (OGCT) is considered to be a relatively uncommon, noncancerous primary bone lesion that may transform into a malignant form in rare cases [1,2]. OGCT typically arises in the epiphysis of long bones and, despite being benign in biological neoplastic context, it can spread locally in an aggressive manner and metastasize [3]. Several classification systems are used to determine OGCT aggressiveness, but none fully capture its local spreading potential [4]. Aim To identify morphological factors determining aggressive local spreading of OGCT. Methods 49 cases of OGCT cases morphologically diagnosed in pathology laboratory from 2009 through 2023 were selected for this study. Selected cases of hematoxylin/eosin-stained osteal tissue fragments were analyzed by light microscopy evaluating secondary osteal morphological features of aggressive local spreading and bone aneurysms. Gender, anatomical localization, tumor volume (cm3), presence of neurological symptoms (pain, paresthesia), local osteal symptoms (tumor mass, fracture, deformation), and skeletal dysfunction of the patients were also included in statistical analysis. Statistical analysis, including descriptive statistic (mean (standard deviation), median, interquartile range), tests of normality, Student’s T test, χ2 test, crosstabs of nominal by interval, was performed by applying SPSS 29.0 software (statistical significance p<0.05). Results 46.9% (n=23) men of 39.13 (14.38) years old (y. o.) and 53.1% (n=26) women of 40.04 (16.9) y. o. (t=0.201; p=0.841) were morphologically diagnosed with OGCT (tumor volume’s median – 9.75 cm3, interquartile range – 63 cm3), mostly in lower extremity bones (61.2%, n=30). Morphological features of aggressive local OGCT spreading were detected in 16.3% (n=8), whereas secondary osteal aneurysms were determined in 10.2% (n=5) OGCT cases. Neurological symptoms were present in 59.2% (n=29) OGCT cases. 24.5% (n=12) OGCT cases manifested with local osteal symptoms, and skeletal dysfunction was present in 18.4% (n=9) cases. Morphological features of aggressive local OGCT spreading were more likely to manifest in trunk OGCTs (χ2=12.28; p=0.02) and were most likely directly associated with tumor’s volume (η2=0.18). No secondary osteal aneurysms were detected for all men patients with OGCTs (χ2=4.92; p=0.05). Morphological features of aggressive OGCT local spreading were similar in presence of neurological (χ2=1.861; p=0.173), local osteal symptoms (χ2=0.875; p=0.35), and skeletal dysfunction (χ2=0.22; p=0.639). Conclusions Morphological features of local aggressive OGCT spreading are more likely to be associated with the tumor‘s volume and the OGCTs diagnosed in the trunk skeleton, suggesting.