10. Pathology and Oncology MCQs

A 35-year-old male presents with a dull ache in his lower leg. Radiographs show a well-circumscribed, multilobular, osteolytic lesion in the anterior diaphysis of the tibia. Biopsy reveals a biphasic pattern consisting of nests of basaloid cells surrounded by a bland fibrous stroma. Which of the following markers will the epithelial-like cells express?

A 28-year-old female presents with a painless mass in her abdominal wall. Excision is performed, and pathology shows a proliferation of uniform spindle cells in a collagenous stroma with deep infiltration into adjacent skeletal muscle. Immunohistochemistry shows nuclear beta-catenin accumulation. Patients with multiple such tumors should be screened for which of the following syndromes?

A 18-year-old male presents with severe, progressive thigh pain that awakens him at night but is dramatically relieved by ibuprofen.

Imaging reveals a thick area of cortical sclerosis containing a 7-millimeter central radiolucent nidus. The intense pain experienced by this patient is primarily mediated by excessive local production of which substance?

An 8-year-old boy presents with back pain. Radiographs demonstrate vertebra plana of T8. Biopsy reveals a proliferation of mononuclear cells with indented, "coffee-bean" shaped nuclei mixed with eosinophils. Electron microscopy identifies tennis-racket shaped Birbeck granules. Which genetic mutation is most frequently identified in this disease?

A 65-year-old male presents with hypercalcemia, renal insufficiency, anemia, and low back pain. Radiographs of the skull reveal multiple "punched-out" lytic lesions. Bone marrow biopsy demonstrates sheets of cells with an eccentric nucleus, clumped "clock-face" chromatin, and a perinuclear halo. These neoplastic cells will strongly express which of the following surface markers?

A 55-year-old male presents with deep groin pain. Radiographs of the proximal femur show a poorly marginated radiolucent lesion with stippled "rings and arcs" calcifications and endosteal scalloping. Biopsy demonstrates malignant cartilage permeating between preexisting host bone trabeculae. Which of the following gene mutations is most commonly implicated in this primary bone tumor?

A 14-year-old girl presents with a rapidly enlarging mass deep in her calf. Biopsy reveals a proliferation of small round blue cells with eosinophilic cytoplasm, separated by fibrous septa into spaces resembling pulmonary alveoli. Which translocation is diagnostic and confers an unfavorable prognosis in this sarcoma?

A 35-year-old male undergoes wide local excision of a slow-growing, multi-nodular mass on his trunk. Histology reveals bland spindle cells arranged in a "storiform" or cartwheel pattern, deeply infiltrating the subcutaneous fat in a "honeycomb" pattern. The tumor cells are strongly positive for CD34. Which cytogenetic abnormality is characteristic of this lesion?

A 24-year-old male presents with a deep, slow-growing soft tissue mass in his popliteal fossa. Core needle biopsy demonstrates a biphasic tumor with both epithelial and spindle cell components. Molecular analysis of this tissue is most likely to reveal which of the following characteristic chromosomal translocations?

Which of the following features most reliably distinguishes an osteoblastoma from an osteoid osteoma on advanced imaging and histologic review?

A 14-year-old boy presents with a painful, swollen thigh. Radiographs reveal a permeative diaphyseal lesion with an 'onion skin' periosteal reaction. Core needle biopsy shows sheets of small round blue cells. Which of the following genetic translocations is most characteristic of this patient's underlying diagnosis?

A 15-year-old girl is diagnosed with conventional, high-grade osteosarcoma of the distal femur. She completes a course of neoadjuvant chemotherapy and subsequently undergoes wide surgical resection. Pathological analysis of the resected specimen evaluates the percentage of tumor necrosis. According to the Rosen/Huvos grading system, what percentage of tumor necrosis is the established threshold to classify her as having a 'good response' to chemotherapy?

Which of the following chromosomal translocations is diagnostic for Synovial Sarcoma?

A 28-year-old female presents with a slow-growing, painful mass in her right foot. MRI reveals a deep soft tissue mass that is lobulated and shows inhomogeneous enhancement. Core biopsy demonstrates a biphasic tumor with spindle cells and epithelial components. Which of the following chromosomal translocations is most characteristic of this diagnosis?

A 22-year-old female presents with a slowly enlarging, painless mass at the posterior aspect of the distal femur. Radiographs reveal a heavily ossified, dense mass arising from the surface of the bone with a radiolucent 'string sign' separating the mass from the underlying cortex. Biopsy confirms a low-grade malignant bone-forming tumor. Genetic analysis of this tumor is most likely to show amplification of which of the following genes?

A 15-year-old patient with multiple enchondromatosis presents with extensive cartilaginous lesions primarily localized to one side of the body, sparing the soft tissues. Recent literature has identified that the pathogenesis of this syndrome (Ollier disease) is most closely linked to a somatic mosaic mutation in which of the following genes?

A 60-year-old female with a history of metastatic breast carcinoma presents with intractable mechanical mid-thoracic back pain.

Imaging demonstrates a large lytic lesion involving the T8 vertebral body and bilateral pedicles. There is no epidural tumor extension, and she is neurologically intact. Her Spinal Instability Neoplastic Score (SINS) is calculated to be 11. According to the NOMS framework, what is the next best step in management?

A 55-year-old male presents with slowly progressive bowel and bladder dysfunction. MRI reveals a large, lobulated presacral mass. CT-guided core needle biopsy shows large cells with abundant, vacuolated cytoplasm (physaliferous cells) in a myxoid background. What is the most appropriate surgical management?

A 55-year-old male with a history of renal cell carcinoma presents with progressive lower extremity weakness and a solitary, highly destructive lytic lesion at T8 causing spinal cord compression. He is planned for an urgent anterior corpectomy and stabilization. Which of the following preoperative interventions is highly recommended to reduce perioperative morbidity?

A 45-year-old female complains of burning and tingling in the plantar aspect of her foot, which worsens after standing. Examination reveals a positive Tinel's sign posterior to the medial malleolus. If an MRI is ordered and identifies a space-occupying lesion compressing the posterior tibial nerve, what is the most common etiology in this specific location?