10. Pathology and Oncology MCQs

A 55-year-old male presents with a painless, slow-growing mass on the posterior aspect of his neck and upper back. Excisional biopsy is performed. Histopathology reveals mature adipocytes mixed with uniform spindle cells, ropey collagen, and a myxoid background. Immunohistochemistry is strongly positive for CD34 and shows loss of Rb1 expression. What is the diagnosis?

A 35-year-old female with a history of Hereditary Multiple Exostoses (HME) presents with progressive, deep pelvic pain. She notes that a long-standing bump on her iliac wing has recently started growing.

MRI demonstrates a cartilage cap of 2.5 cm with new heterogeneous signal characteristics. What is the most likely diagnosis?

A 19-year-old male complains of a lump on the anterior aspect of his mid-tibia. Radiographs show a radiolucent surface lesion with perpendicular sunburst periosteal reaction and cortical scalloping, but no medullary involvement. Biopsy reveals a predominantly chondroblastic matrix with malignant cells. What is the diagnosis?

A 65-year-old woman is diagnosed with an atypical lipomatous tumor (ALT) in her retroperitoneum. Which of the following explains why a retroperitoneal ALT has a worse long-term prognosis compared to an extremity ALT?

A 12-year-old girl is evaluated for worsening right knee pain. Plain films demonstrate an ill-defined, mixed lytic and sclerotic lesion in the proximal tibial metaphysis penetrating the cortex.

Which of the following histologic findings is required to confirm the diagnosis of conventional osteosarcoma?

A 12-year-old boy presents after a mild knee twist. Radiographs reveal an incidental finding in the distal femur metaphysis as seen in the provided image.

The lesion is eccentrically located, lytic, and has a sclerotic margin. The patient is completely asymptomatic. What is the most appropriate next step in management?

A 22-year-old female presents with progressive weakness and pain in her shoulder over the past year. Radiographs demonstrate severe, progressive bone loss of the clavicle and scapula with tapering of the remaining bone ends.

Biopsy shows benign vascular proliferation without atypia. Which of the following is the most likely diagnosis?

A 12-year-old boy presents with knee pain. Radiographs reveal an incidental cortically based, eccentric, lytic lesion with a sclerotic rim in the distal femoral metaphysis.

What is the most appropriate management for this lesion?

A 16-year-old male presents with a painful distal thigh mass. Imaging shows a destructive metaphyseal lesion with a 'sunburst' periosteal reaction. Biopsy confirms high-grade conventional osteosarcoma. What is the standard systemic chemotherapeutic regimen used in the neoadjuvant and adjuvant settings?

A 9-year-old boy presents with thigh pain and a fever. Radiographs show a permeative diaphyseal lesion in the femur with 'onion-skin' periostitis. Biopsy shows small round blue cells. Which specific genetic translocation is most commonly associated with this tumor?

A 12-year-old asymptomatic boy has an incidental finding on a knee radiograph: an eccentric, multilocular, lucent cortical lesion with a sclerotic rim in the distal femoral metaphysis.

What is the most appropriate management?

A 25-year-old female presents with progressive shoulder weakness and pain. Radiographs demonstrate near-complete disappearance of the clavicle and acromion without an associated soft-tissue mass. Biopsy reveals extensive angiomatous and lymphatic proliferation.

What is the most likely diagnosis?

A 16-year-old male complains of distal femur pain. Imaging shows a permeative metaphyseal lesion with a 'sunburst' periosteal reaction. Biopsy confirms high-grade conventional osteosarcoma. What is the standard sequence of treatment for this patient?

A 55-year-old male presents with deep thigh pain. Radiographs demonstrate a lytic lesion in the proximal femur with intralesional 'rings and arcs' calcifications. MRI shows extensive endosteal scalloping. Biopsy confirms a Grade 2 conventional chondrosarcoma. What is the primary modality of treatment?

A 65-year-old male presents with severe back pain. Imaging shows a pathological compression fracture of L4. Laboratory tests reveal hypercalcemia, anemia, and an elevated total serum protein. Which diagnostic test is most essential to confirm the underlying diagnosis and identify the specific protein abnormality?

A 14-year-old boy presents with fever, malaise, and localized thigh pain. Radiographs reveal a diaphyseal destructive lesion with an 'onion-skin' periosteal reaction. Which specific chromosomal translocation is the diagnostic hallmark of the most likely bone tumor?

An asymptomatic 12-year-old boy presents after a mild knee injury. Radiographs show a well-circumscribed, eccentrically located, multilobulated radiolucent lesion with a sclerotic margin in the distal femoral metaphysis.

What is the most appropriate next step in management?

A 25-year-old patient presents with progressive, painless shoulder weakness and deformity over several years. Radiographs reveal progressive resorption of the proximal humerus and glenoid without evidence of malignant cells or infection.

What is the pathophysiological mechanism of this disease?

A 40-year-old patient has an incidentally discovered cartilaginous lesion in the proximal humerus. Which of the following findings is most suggestive of secondary malignant transformation to chondrosarcoma?

A 16-year-old male complains of right thigh pain that is worse at night and dramatically relieved by ibuprofen. Imaging shows a cortical thickening with a 7 mm radiolucent nidus in the femoral diaphysis. Radiofrequency ablation (RFA) is planned. What is the most critical anatomical consideration when performing RFA for this lesion?