Oncol. Gastroenterol. Hepatol. Reports Vol.1 / Issue 1 / Jul–Dec, 2012 41 Case Report OGH Reports Chondroblastic osteosarcoma of proximal fibula Yasir Salam Siddiqui, 1 * Pathania VP, 1 Manisha Mendiratta, 2 Nusra Rahman 3 1 Dept. of Orthopaedic Surgery, SRMS - Institute of Medical Sciences, Bhojipura, Bareilly, UP, India 2 Dept. of Pathology, SRMS - Institute of Medical Sciences, Bhojipura, Bareilly, UP, India and - 1 Junior Resident, Dept. of Anatomy 3 J.N. Medical College, AMU, Aligarh, UP, India INTRODUCTION Osteosarcoma is the most common form of primary malignant bone tumour that occurs during childhood and adolescence. The incidence of new diagnoses peaks in the second decade of life. Osteosarcoma most com- monly develops at sites of rapid bone turnover, such as the distal femur, proximal tibia, and proximal humerus. Less common sites for osteosarcoma include the pelvis, the spine, and the craniofacial bones. The proximal fib- ula is a relatively rare site for osteosarcoma and in Mayo series reported incidence was only 2%. [1] Radiologically, osteosarcoma typically presents as osteoblastic and/or osteolytic lesion with ill-defined borders and associated soft-tissue mass. Treatment typically includes preopera- tive chemotherapy, surgical resection, and postoperative chemotherapy. Limb-salvage procedures with wide sur- gical margins are the mainstay of surgical intervention. The management of osteosarcoma of the proximal fibula is demanding for the treating surgeon because of the proximity of the common peroneal nerve to the lesion. Resection of malignant tumours often requires wide sur- gical margins and to obtain such margin, at times resec- tion of the common peroneal nerve is done. The purpose of this case report is to discuss the difficult aspects of diagnosis and management of osteosarcoma of proximal fibula. The case report is presented after obtaining informed consent from the patient. CASE REPORT A 17 year old male patient presented to our institu- tion with 5 months history of gradually increasing pain and swelling in the region of his right proximal leg. He did not give any history of trauma, fever or any other systemic illness. Examination revealed firm and tender swelling involving the proximal fibula. Movements of the knee were within normal limits. Common peroneal nerve was intact. The patient’s laboratory results were normal except for low levels of haemoglobin, elevated levels of lactate dehydrogenase and alkaline phosphatase. Plain radiographs of the right knee showed the inter- rupted periosteal reaction involving the meta-diaphysis of proximal fibula. The lesion seems to have infiltrated *Corresponding address: Dr. Yasir Salam Siddiqui Assistant Professor, Dept. of Orthopaedic Surgery SRMS - Institute of Medical Sciences, Bhojipura, Bareilly, UP, India Mobile: +919837343400, Fax: 00915712702758 Email: yassu98@gmail.com DOI: 10.5530/ogh.2012.1.10 ABSTRACT Osteosarcoma is the most common form of primary malignant bone tumour that occurs during childhood and adolescence. The incidence of new diagnoses peaks in the second decade of life. The metaphysis of the long bones is the site of predilection, and, in declining order, it commonly involves distal femur, proximal tibia, and proximal humerus. The proximal fibula is a relatively rare site for osteosarcoma. We are reporting a case of osteosarcoma of proximal fibula in a 17-year-old male child and discuss the difficult aspects of diagnosis and management. Keywords: Chondroblastic osteosarcoma, bone tumour, metaphysis.