1: Surgical Anatomy.- Normal Anatomy and Magnetic Resonance Appearance of the Pelvis.- Imaging Examinations of Tumors.- 2: Incidence and Histological Classification.- Incidence and Histological Classification of Pelvic Tumors.- 3: Biopsy.- Efficacy of Aspiration Cytology and a Practical Method of Open Biopsy.- 4: Preparation.- Preparation, Intraoperative Care, and Postoperative Treatment.- 5: Approach.- Systemic Surgical Approach for the Pelvis.- 6: Reconstruction.- Reconstructive Surgery After Wide Resection of Pelvic Tumors.- Microsurgical Reconstruction After Pelvic Tumor Resection.- Simultaneous Reconstruction of the Ilium and Hip Joint with a Free Vascularized Foot-Ankle Joint Graft After Wide Resection of Ewing’s Sarcoma of the Ilium.- 7: Related Topics.- Topics Relating to Pregnancy, Reconstruction, Vesicorectal Disturbance, and Complications.- 8: Complications.- Complications and Sequelae.- 9: Outcomes.- Oncological and Functional Outcomes, Vesicorectal Dysfunction, and Complications.- 10: Case Presentations.- Case 1: Resection of a Giant Cell Tumor of the Sacrum, and Unilateral Reconstruction of the Sacroiliac Joint in a 51-Year-Old Woman.- Case 2: Treatment of a Giant Cell Tumor of the Sacrum in a 27-Year-Old Man, Using Four Struts at the Lumbosacral Level to Support the Trunk.- Case 3: Wide Resection of a Malignant Fibrohistiocytoma of the Ilium and Unilateral Reconstruction of the Sacroiliac Joint in a 28-Year-Old Man.- Case 4: Recurrent Synovial Sarcoma of the Pubic Region Treated with a Wide Resection, Including the Pubic Bone and Female Genitalia in a 50-Year-Old Woman.- Case 5: Wide Resection of a Large Chondrosarcoma of the Ilium and Reconstruction of the Pelvic Ring in a 55-Year-Old Man.- Case 6: Reconstruction of the Pelvic Ring and Obturator Nervewith Vascularized Tissue Transfers in a 32-Year-Old Woman with a Chondrosarcoma of the Inferior Pubic Ramus.- Case 7: Partial Resection of the Sacrum and Reconstruction of the Pelvic Ring in a 41-Year-Old Man with a Giant Cell Tumor of the Sacrum.- Case 8: Wide Excision of a Metastatic Renal Cell Carcinoma of the Ilium in a 54-Year-Old Woman.- Case 9: Resection of a Chordoma of the Sacrum in a 40-Year-Old Man.- Case 10: Chondrosarcoma of the Left Acetabulum Treated by Osteotomy and Hip Reconstruction with Conventional Total Hip Arthroplasty in a 62-Year-Old Woman.- Case 11: Internal Hemipelvectomy and Constrained Total Hip Arthroplasty for the Treatment of Chondrosarcoma of the Acetabulum in a 52-Year-Old Woman.- Case 12: Simple Wide Resection of an Osteosarcoma of the Pubis and Reinforcement of the Inguinal Soft Tissue with Marlex Mesh in a 13-Year-Old Girl.- Case 13: Crossover Bypass Graft for Reconstruction of the External Iliac Vein After Resection of a Retroperitoneal Dedifferentiated Liposarcoma in a 60-Year-Old Woman.- Case 14: Massive Sacral Chordoma Resected by a Combination of Anterior and Posterior Approaches in a 50-Year-Old Man.- Case 15: Metastatic Type II Tumor in a 67-Year-Old Man Treated by Standard Total Hip Arthroplasty After Three-Dimensional Pelvic Osteotomy and Preservation of the Posterior Column of the Acetabulum.- Case 16: Successful Delivery After a Hemipelvectomy in a 28-Year-Old Woman with Recurrent Osteosarcoma of the Proximal Femur.- Case 17: En Bloc Resection of the Entire Sacrum and L5 Vertebra for Chondrosarcoma of the Sacrum in a 57-Year-Old Man.- A List of Further References with Remarks.