10. Pathology and Oncology MCQs

A 15-year-old boy sustains a minor trauma to his distal phalanx and develops localized swelling. Radiographs show a well-circumscribed lytic lesion in the terminal phalanx without periosteal reaction. He had a crush injury to the same finger five years ago. What is the most likely diagnosis?

A 28-year-old male with a history of recurrent primary synovial chondromatosis of the hip presents with rapidly increasing pain and a palpable mass. MRI reveals marrow replacement in the femoral neck. What is the most reliable imaging finding suggesting malignant transformation in this patient?

During surgical curettage of a suspected unicameral bone cyst (UBC) in the proximal humerus of a 10-year-old, the surgeon notes a thick membrane and profuse, pulsatile bleeding from the cavity. What is the most appropriate next step?

A 45-year-old male with a history of primary synovial chondromatosis of the knee presents with rapid onset of worsening pain and joint swelling over the last 3 months. Imaging demonstrates cortical erosion and a permeative soft tissue mass. What is the approximate rate of malignant transformation associated with this patient's underlying condition?

A 9-year-old boy presents with sudden shoulder pain after throwing a baseball. Radiographs reveal a pathologic fracture through a centrally located, expansile radiolucent lesion in the proximal humerus metaphysis. A cortical fragment is seen resting at the dependent portion of the lesion. Which of the following is the most appropriate initial management?

A 14-year-old girl presents with knee pain. MRI reveals an eccentric, expansile metaphyseal lesion in the distal femur with multiple fluid-fluid levels. Biopsy confirms a primary aneurysmal bone cyst (ABC). Which of the following genetic aberrations is uniquely characteristic of this primary lesion?

A 22-year-old woman with known polyostotic fibrous dysplasia presents with progressive symptomatic varus deformity of her proximal femur (shepherd's crook deformity). Surgical reconstruction is planned. Which of the following bone grafting techniques is most appropriate for managing the resultant bony defects after corrective osteotomy?

A 45-year-old male presents with chronic knee pain and mechanical catching. Imaging reveals multiple intra-articular calcified bodies. A diagnosis of primary synovial chondromatosis is suspected. Which of the following best describes the fundamental pathophysiology of this condition?

A 12-year-old girl presents with a destructive, expansile lytic lesion in the proximal tibia. MRI reveals multiple fluid-fluid levels within the lesion. An incisional biopsy confirms a primary aneurysmal bone cyst (ABC). Which of the following genetic alterations is highly specific to this primary tumor?

A 9-year-old boy sustains mild trauma to his shoulder. Radiographs show a central, fully radiolucent, mildly expansile lesion in the proximal humeral metaphysis. A small cortical bone fragment is seen resting at the dependent portion of the cyst. What is this sign called?

When interpreting advanced imaging for a suspected aneurysmal bone cyst (ABC) in the distal femur, which of the following MRI findings is highly characteristic, though not entirely pathognomonic?

A 55-year-old male with a 10-year history of primary synovial chondromatosis of the hip presents with acute worsening of pain and a rapidly expanding soft tissue mass. If a malignant transformation has occurred, what is the most likely histologic diagnosis?

A 9-year-old female presents with multiple bony deformities and large cutaneous macules with irregular, jagged borders. She is also noted to have advanced bone age and early breast development. Which of the following is the most likely endocrine abnormality in this patient?

To differentiate a simple (unicameral) bone cyst from an aneurysmal bone cyst on plain radiographs, the anatomic location within the host bone is a key feature. Which of the following locations is classic for an active unicameral bone cyst in a child?

A 45-year-old male presents with long-standing knee swelling and mechanical symptoms. X-rays show multiple uniform intra-articular calcified loose bodies. If this condition undergoes malignant transformation, which of the following is the most likely resulting pathology?

A 14-year-old girl presents with a painful, expansile, lytic lesion in the proximal humerus. MRI reveals multiple fluid-fluid levels. Which of the following genetic translocations is most characteristic of this primary lesion?

A 25-year-old female presents with multiple expansile "ground glass" bone lesions, cafe-au-lait spots with irregular borders, and a history of precocious puberty. This condition is caused by a somatic activating mutation in which of the following?

A 32-year-old male with polyostotic fibrous dysplasia presents with increasing thigh pain and a progressive "shepherd's crook" deformity of his proximal femur. What is the most appropriate surgical management?

A 5-year-old boy presents with anterior tibial bowing. Radiographs show a purely lytic, intracortical lesion in the anterior diaphyseal cortex of the tibia. A biopsy shows trabeculae of woven bone rimmed by prominent osteoblasts in a fibrous stroma. What other condition must be carefully ruled out due to its histologic and anatomic similarity?

A 6-year-old boy presents with an asymmetric, painless overgrowth on the medial aspect of his right ankle. Radiographs show an irregular, lobulated mass arising from the medial epiphysis of the distal tibia. What is the most likely diagnosis?