Benign Tumors Of Bone MCQs

Answer- A. Osteoid osteoma Dense, homogenous mineralization (calcification) is typical of osteoid matrix, formed by benign and malignant bone forming lesions. 1265. Which of the following is true about Giant cell tumor a) Usually presents as a lytic lesion with sclerotic rim b) Always beingn c) Epiphyseal origin d) Seen in age less than 15 years Correct Answer - C Answer- C. Epiphyseal origin GCT is an osteolytic tumor arising from the epiphysis and is common between the age of 20-40 years. The commonest sites are lower end of femur and upper end of tibia. Other common sites are lower end radius and upper end of humerus. It may also occur in the spine and sacrum. The radiological features are : -

Malignant change can cause pain in osteochondroma. However the malignancy that arises in osteochondroma is chondrosarcoma and not osteosarcoma. The causes of pain in osteochondroma are Bursitis (most common cause) Fracture of the pedicle Compression of an adjacent nerve Malignant change - chondrosarcoma. Reference: Miler's 8th Edition of Review of Orthopaedics, page no. 1881

Codman's tumor is another name for Chondroblastoma. It should not be confused with Codman's triangle which is a type of periosteal reaction, most commonly seen in osteosarcoma. Reference: Tachdjian's Pediatric Orthopaedics 5th edition page no. 1109

Osteoid Osteoma: Benign bone forming lesion considered to be the most common true benign tumor of the bone Age group: 2 nd -3 rd decades Male: Female 3:1 Lower extremity, long bones, Posterior elements spine, Diaphyseal/metaphyseal Pain: worse at night XRAY - Cortical radiolucent nidus High levels of cyclooxygenases and prostaglandins in the lesion Frequently responds to NSAIDs HISTOLOGY - Trabeculae surrounded by loose fibrovascular tissue TREATMENT - NSAIDs, Burr down technique, Radiofrequency ablation. Reference: Maheshwari, Essential Ortho, 5 th edition, Page no. 236.

Chondroblastoma This is a cartilaginous tumor containing characteristic multiple calcium deposits. It occurs in young adults and is located around the epiphyseal plate . Bones around the knee are commonly affected. Radiologically, there is a well-defined lytic lesion surrounded by a zone of sclerosis. Areas of calcification within the tumor substance give rise to a mottled appearance . Treatment is by curettage and bone grafting. Chondroblastoma(Codman tumors): Microscopically they are composed of chondroblasts, chondroid matrix, cartilage with occasional giant multinucleated cells(which may lead to the incorrect diagnosis of giant cell tumor). Calcium deposition surrounding the chondroblasts, which are typically polyhedral shape, results in typical ' chicken-wire calcification '(pathognomonic) Reference: Maheshwari Essentials Ortho, 5 th edition, Page no. 236.

Important facts Commonest bone malignancies Secondaries(metastases) Commonest primary malignant tumor → Multiple myeloma Commonest primary malignant tumor of long bones → Osteosarcoma Commonest benign tumor of bonne → Osteochondroma(Osteochondroma is not true neoplasm since its growth stops with cessation of growth at the epiphyseal plate) Commonest true benign tumor of bone → Osteroid osteoma Commonest benign tumor of hand → Enchondroma Reference: Apley's, 9th edition, Pg: 197.

Osteosarcoma never involves the vertebra. Metastasis can occur rarely in this age group, but it usually involves the vertebral body and the pedicles. Tumors that can commonly involve the transverse process are ABC and Osteoblastoma. Osteoblastoma will have a large nidus and surrounding sclerosis, hence it is not a lytic lesion The classical expansile lytic lesion of the transverse process is aneurysmal bone cyst (ABC). Reference: J. Maheshwari's 5th Edition of Essential Orthopaedics page no. 237

Chondrosarcoma can arise from other benign cartilage tumors especially enchondromas. In the given options, the only syndrome that presents with enchondromas is Maffucci syndrome. Maffucci syndrome has a 100% risk of malignant change. Maffucci syndrome Multiple enchodromas Soft tissue angiomas Phleboliths Jaffe campanacci syndrome Muliple Non ossifying fibromas Mazabraud syndrome Polyostotic fibrous dysplasia Myxomas McCune Albright syndrome Polyostotic fibrous dysplasia Cafe au lait spots Precocious puberty Reference: J. Maheshwari's 5th Edition of Essential Orthopaedics page no. 248