21 year old female came with complaints of pain over right hip since 3 weeks which was acute in onset gradually progressive and dull aching in character. Examination showed there was restricted internal rotation and abduction of right hip movements, with no sensory or motor deficits of bilateral lower limbs. Blood investigations showed marginally elevated erythrocyte sedimentation rate, while the rest were within normal limits.MRI scan of pelvis showed margin enhancing focus at right acetabular roof region with perifocal marrow changes. Trucut biopsy was done and showed mildly hypercellular hyaline cartilage with lobular arrangement and focal myxoid change permeating the bone trabeculae and occasional peripheral aggregates of osteoclast giant cells. She was diagnosed to have right pelvic non metastatic chondrosarcoma and underwent right internal hemipelvectomy (partial type 1and 2) using 3D printed cutting jig and ECRT(extracorporeal radiotherapy) of resected specimen with reimplantation and fixation using custom made 3d printed plates for posterior column, pre bent anterior column plate. Conclusion: Despite the rarity of the condition, the possibility of non metastatic chondrosarcoma in pelvis should be taken into account in these circumstances. This case shows the role of surgical resection, ECRT and reimplantation of irradiated bone with help of 3D printing in management and draws attention towards early detection and definitive management with respect to the rarity of the disease and the site of the bone involvement

Keywords : Chondrosarcoma, ECRT- Extracorporeal radiotherapy, 3D printing