Posts: 3,675,937
Threads: 734,344
Joined:
Sep 2021
Reputation:
5
Choice (D) is the correct answer.
Ewing sarcomas are aggressive, highly malignant, primitive neuroectodermal tumors that affect children and adolescents less than 15 years of age. The tumor can affect almost any bone. Common sites of tumor growth include the pelvis, femur, tibia, humerus, and ribs. Patients may present with pain and swelling of weeks to months duration at the tumor site. Fever, fatigue, and weight loss are other common symptoms. Radiographs may show an onion skin appearance. Ewing sarcomas are characterized histologically by sheets of small, malignant blue cells and are associated with 11:22 translocations.
Wilms tumor (Choice A) is the most common renal tumor in children. It is caused by abnormal proliferation of metanephric blastema cells and usually presents as an abdominal mass. Hypertension, fever, anemia, and hematuria are associated with Wilms tumor.
Osteoid osteomas (Choice B) are benign bone tumors seen primarily in young males. The majority of osteoid osteomas affect the appendicular skeleton, in particular the proximal femur, tibia, and the humerus. The spine may also be affected. The classic presentation of an osteoid osteoma is dull pain that is worse at night and worse with activity. The pain is temporarily relieved with aspirin. Radiographs show a radiolucent nidus with a surrounding area of reactive sclerosis. Histologically, osteoid osteomas are characterized by osteoid, woven bone, and osteoclasts.
Osteosarcomas (Choice C) are the most common malignant bone tumors. They are very aggressive tumors that produce malignant osteoid. They typically affect young adult males 10-20 years of age. The tumor occurs near metaphyseal growth plates, with the distal femur and proximal tibia being the most common sites. Pain with activity is a common complaint. X-rays may show a Codman triangle, resulting from periosteal elevation, and there may be a sunburst appearance.
Osteochondromas (Choice E) are the most common benign bone tumor. They are typically seen in males less than 25 years of age. Osteochondromas most often affect the metaphysis of long bones, in particular the distal femur, the proximal tibia, and the proximal humerus. The tumors consist of a bony stalk with a cartilaginous cap. The marrow, cortex, and periosteum is continuous with the normal bone. If osteochondromas become large enough, they can compress adjacent structures and become symptomatic. Fracture through the bony stalk can result in severe pain.
