10. Pathology and Oncology MCQs

A 25-year-old female presents with a painless mass on the posterior aspect of her distal thigh. Radiographs reveal a dense, extensively ossified mass attached to the posterior cortex of the distal femur via a broad base. Biopsy shows well-formed woven bone trabeculae within a bland fibrous stroma, with minimal cellular atypia. What is the most likely diagnosis and the most appropriate standard of care?

A 14-year-old boy presents with a 3-month history of nocturnal thigh pain and low-grade fever. Radiographs demonstrate a permeative, diaphyseal lytic lesion in the femur with a multilamellated 'onion-skin' periosteal reaction. Core needle biopsy reveals uniform small round blue cells. Which of the following cytogenetic abnormalities is most characteristically associated with this patient's diagnosis?

A 55-year-old man presents with a constant, dull aching pain in his right pelvis that has been progressively worsening over the past 6 months. Radiographs demonstrate a large lytic lesion in the ilium with internal 'ring-and-arc' calcifications and focal cortical breakthrough. Biopsy confirms a grade II (intermediate-grade) chondrosarcoma. Which of the following is the most appropriate management?

A 65-year-old man presents with intractable lower back pain and fatigue. Radiographs show multiple punched-out lytic lesions in the skull and several vertebral compression fractures. Laboratory tests reveal hypercalcemia and a normocytic anemia. Serum protein electrophoresis shows an M-spike. Which of the following imaging modalities is the most sensitive for assessing the total extent of skeletal involvement in this condition?

A 19-year-old man presents with localized right leg pain that is significantly worse at night and dramatically relieved within 30 minutes of taking ibuprofen. Imaging demonstrates a 7-mm radiolucent nidus surrounded by dense, reactive sclerotic bone in the anterior cortex of the mid-diaphyseal tibia. If the patient desires definitive treatment but wishes to avoid open surgery, which of the following is considered the standard of care?

A 28-year-old man presents with a slowly enlarging, relatively painless mass around his left ankle. Radiographs show an eccentric soft tissue mass with stippled calcifications adjacent to, but not involving, the joint space. MRI reveals a heterogeneous mass with a 'triple signal' pattern on T2 sequences. Biopsy confirms a biphasic tumor comprised of epithelial and spindle cell components. Which chromosomal translocation is pathognomonic for this tumor?

A 45-year-old woman is referred after an incidental finding of a calcified lesion in her proximal humerus during a routine chest radiograph. Subsequent shoulder MRI shows a 3 cm well-circumscribed, lobulated cartilaginous lesion localized entirely within the medullary canal. There is no endosteal scalloping, cortical breakthrough, periosteal reaction, or soft tissue extension. The patient reports absolutely no pain in her shoulder. What is the most appropriate management?

A 55-year-old man presents with a painful mass in his proximal humerus. A radiograph reveals an intralesional, destructive process with stippled, popcorn-like calcifications. Biopsy confirms the diagnosis of a conventional central chondrosarcoma. Which of the following genetic mutations is most commonly associated with this primary bone tumor?

A 24-year-old woman presents with a slowly enlarging, painful mass deep within the plantar aspect of her foot. MRI demonstrates a well-circumscribed soft tissue mass near the plantar fascia. Biopsy reveals a biphasic tumor consisting of epithelial cells forming glandular structures and spindle cells in a fascicular pattern. Which cytogenetic abnormality is diagnostic for this tumor?

A 35-year-old male presents with a slowly enlarging, painless mass around his left knee. MRI demonstrates a soft tissue mass adjacent to the joint capsule but without intra-articular extension. Biopsy reveals a biphasic pattern consisting of spindle cells and epithelial cells. Which of the following chromosomal translocations is most characteristic of this patient's diagnosis?

A 14-year-old boy presents with pain and swelling over his proximal humerus after minor trauma. Radiographs show an expansile, radiolucent, metaphyseal lesion. MRI demonstrates multiple fluid-fluid levels within the lesion. A core biopsy reveals blood-filled cavernous spaces lacking an endothelial lining. A cytogenetic abnormality in which of the following genes is most likely associated with the pathogenesis of this primary lesion?

A 15-year-old boy presents with fever, weight loss, and severe mid-thigh pain. Radiographs demonstrate a permeative diaphyseal lesion of the femur with a prominent 'onion-skin' periosteal reaction. Histology reveals solid sheets of uniform small round blue cells. Immunohistochemistry is strongly positive for CD99. Which of the following fusion gene products is the primary driver of this malignancy?

A 14-year-old boy presents with right knee pain that wakes him at night. Radiographs show a destructive metaphyseal lesion of the distal femur with a sunburst periosteal reaction and Codman's triangle. A biopsy confirms high-grade osteoblastic osteosarcoma. A germline mutation in which of the following tumor suppressor genes would most strongly predispose this patient to both this primary bone tumor and breast cancer later in life?

A 55-year-old man presents with a constant, dull ache in his pelvis. Radiographs reveal a large, lytic lesion in the ilium with 'popcorn-like' chondroid calcifications. Biopsy demonstrates hypercellular hyaline cartilage with plump, pleomorphic, and binucleated chondrocytes penetrating host bone trabeculae. Which of the following represents the most appropriate primary treatment modality for the conventional type of this tumor?

A 19-year-old male complains of severe right thigh pain that is significantly worse at night and promptly relieved by NSAIDs. Computed tomography (CT) displays a 1-cm radiolucent nidus surrounded by dense, sclerotic reactive bone in the femoral diaphysis. The profound pain experienced by this patient is directly mediated by an elevated local concentration of which of the following substances?

A 45-year-old male presents with a deep, painless, intramuscular mass in his thigh. MRI shows a multi-lobulated mass that is hyperintense on T2-weighted images and contains small nodules of macroscopic fat. Histology reveals primitive non-lipogenic mesenchymal cells, an arborizing 'chicken-wire' capillary network, and signet-ring lipoblasts within a prominent myxoid stroma. Which of the following cytogenetic abnormalities is classically associated with this diagnosis?

A 40-year-old male presents with a one-year history of chronic, mild right shoulder pain. Radiographs demonstrate a lytic lesion located purely in the epiphysis of the proximal humerus, with a fine sclerotic margin and central calcification. Histology shows sheets of cells with abundant clear cytoplasm and distinct cell membranes, interspersed with areas of hyaline cartilage and reactive trabeculae of woven bone. What is the most likely diagnosis?

A 15-year-old boy presents with a painful mass in his distal femur. Radiographs reveal a permeative, destructive diaphyseal lesion with a lamellated periosteal reaction. Biopsy reveals sheets of uniform small blue round cells with scant cytoplasm. Cytogenetic analysis is pending. What is the most common translocation associated with this diagnosis, and what fusion protein does it create?