10. Pathology and Oncology MCQs

A 5-year-old boy presents with progressive stiffness of his neck and upper back. Examination reveals a short, medially deviated great toe (microdactyly). A firm, warm soft-tissue mass is palpable in the paraspinal region. The parents request a biopsy of the mass. What is the specific gene mutation, and what is the primary reason biopsy is strictly contraindicated?

A 15-year-old male presents with chronic knee pain. Radiographs reveal a well-circumscribed, eccentrically located lytic lesion in the proximal tibial epiphysis with a thin sclerotic rim. Biopsy demonstrates mononuclear cells with longitudinal nuclear grooves and areas of pericellular 'chicken-wire' calcification. Which of the following is the most appropriate initial management?

A 45-year-old male undergoes a core needle biopsy of a deep thigh mass. Histology reveals a uniform population of round cells, a prominent myxoid stroma, and a branching capillary network resembling 'chicken-wire'. Which specific chromosomal translocation is most characteristic of this soft tissue sarcoma?

A 60-year-old patient presents with a large, slow-growing retroperitoneal mass. Biopsy reveals mature adipocytes with focal areas of nuclear atypia and hyperchromatic stromal cells. Molecular testing demonstrates amplification of a specific gene on chromosome 12q13-15. Which of the following genes is amplified in this tumor?

A 17-year-old male with a history of a treated proximal humerus chondroblastoma presents 3 years later for routine follow-up. A chest CT reveals three small, asymptomatic bilateral pulmonary nodules. Biopsy of a nodule shows benign-appearing chondroblasts identical to the primary tumor. What is the most appropriate management?

Which of the following epigenetic alterations is highly specific for diagnosing chondroblastoma and distinguishing it from other giant cell-rich bone lesions?

Which subtype of liposarcoma is unique in its tendency to spread to extrapulmonary sites, specifically necessitating a whole-spine MRI during initial staging to rule out bone metastases?

A 16-year-old undergoes curettage of a presumed chondroblastoma.

Pathology shows areas of typical chondroblastoma juxtaposed with multiple blood-filled spaces lined by fibrous septa containing giant cells. What does this secondary finding represent?

A 68-year-old male undergoes resection of a retroperitoneal sarcoma. Pathology reveals an abrupt transition from a well-differentiated liposarcoma to a high-grade, non-lipogenic pleomorphic sarcoma. What is the diagnosis?

When differentiating atypical lipomatous tumor (ALT) from well-differentiated liposarcoma (WDL), which of the following is the primary distinguishing factor according to the WHO classification?

An 18-year-old female presents with shoulder pain. Imaging shows a lytic epiphyseal lesion in the proximal humerus with a sclerotic rim. Which of the following immunohistochemical markers would be most helpful in confirming the diagnosis of chondroblastoma?

A 75-year-old female presents with a rapidly growing, painful thigh mass. Biopsy demonstrates a high-grade sarcoma with numerous pleomorphic lipoblasts and complex karyotype with severe aneuploidy. There is no MDM2 amplification or t(12;16) translocation. What is the most likely diagnosis?

Regarding the radiation sensitivity of liposarcoma subtypes, which variant is considered highly radiosensitive and often exhibits dramatic tumor shrinkage following neoadjuvant radiation therapy?

A 40-year-old male presents with hip pain. Radiographs show a lytic lesion in the femoral head epiphysis. Biopsy shows large cells with clear cytoplasm and distinct cell membranes, amidst a cartilaginous matrix. What is the most important differential diagnosis to distinguish from chondroblastoma in this older age group?

A 45-year-old male presents with a deep, painless mass in his posterior thigh. Core needle biopsy demonstrates a myxoid stroma, scattered lipoblasts, and a prominent branching capillary network. Which cytogenetic abnormality is most characteristic of this tumor?

A 14-year-old boy presents with chronic knee pain. Radiographs reveal an eccentric, lytic lesion in the distal femoral epiphysis with a thin sclerotic rim.

Biopsy demonstrates mononuclear cells with grooved nuclei and areas of pericellular 'chicken-wire' calcification. What is the most appropriate definitive management?

A 60-year-old man undergoes resection of a massive retroperitoneal tumor. Histology shows an abrupt transition between areas of well-differentiated adipocytic proliferation and areas of high-grade, non-lipogenic sarcoma. Which molecular marker is critically amplified in this pathology?

A 16-year-old boy presents with progressive shoulder pain. Radiographs demonstrate an epiphyseal lesion in the proximal humerus. Biopsy confirms chondroblastoma. Two years after successful curettage, routine imaging reveals three small, asymptomatic lung nodules. Biopsy of a lung nodule shows histologically benign chondroblastoma. What is the most appropriate management?