10. Pathology and Oncology MCQs

A 12-year-old boy presents with a painful, enlarging mass around his distal thigh. Radiographs reveal a metaphyseal permeative lesion with a sunburst periosteal reaction and Codman's triangle. A biopsy reveals malignant, high-grade spindle cells producing osteoid matrix. What is the most appropriate definitive management protocol?

A 65-year-old female with a history of multiple myeloma presents with severe, functionally limiting thigh pain. Radiographs reveal a lytic lesion in the peritrochanteric region of her proximal femur. The lesion occupies greater than 2/3 of the cortical diameter. According to the Mirels' criteria, what is her score and the recommended orthopedic management?

A 19-year-old male presents with chronic right thigh pain that is noticeably worse at night and dramatically relieved by NSAIDs. Radiographs show a small radiolucent nidus surrounded by intense, dense reactive sclerosis in the diaphyseal region. What is the most common anatomic location for this specific benign bone tumor overall?

A 45-year-old male presents with worsening sacral pain and bowel dysfunction. Radiographs reveal a large, destructive midline radiolucent lesion in the sacrum. Histological examination of a biopsy specimen shows lobules of physaliferous cells with vacuolated cytoplasm embedded in a myxoid stroma. What is the most likely diagnosis?

A 15-year-old boy presents with progressive knee pain. Radiographs show a purely lytic lesion in the proximal tibia epiphysis that crosses the physis. Histology demonstrates mononuclear cells with longitudinal nuclear grooves and pericellular 'chicken-wire' calcifications. What is the most likely diagnosis?

A 60-year-old female with a history of breast cancer presents with a painful lytic lesion in the diaphysis of her femur. According to the Mirels' criteria, which of the following aggregate scores is generally considered the threshold to recommend prophylactic internal fixation?

A 14-year-old boy presents with a diaphyseal femur lesion showing an 'onion skin' periosteal reaction. Biopsy reveals sheets of small round blue cells. Which of the following chromosomal translocations is most characteristic of this lesion?

A 12-year-old boy is diagnosed with a diaphyseal femur lesion. Biopsy demonstrates a sheet of uniform small round blue cells. Cytogenetic analysis reveals a t(11;22)(q24;q12) chromosomal translocation. Which resulting fusion gene is highly specific for this diagnosis?

A 16-year-old patient with an osteosarcoma of the distal femur completes an initial 10-week course of neoadjuvant chemotherapy, followed by wide surgical resection. Pathological analysis of the resected specimen is performed. Which histological parameter is the most robust prognostic indicator for long-term overall survival?

A 10-year-old boy presents with multiple cafe-au-lait spots, polyostotic fibrous dysplasia, and precocious puberty. What is the underlying genetic mutation associated with this syndrome?

Which of the following bone tumors is characterized histologically by irregular spicules of woven bone lacking prominent osteoblastic rimming, set in a fibrous stroma?

In the Enneking staging system for benign musculoskeletal tumors, what defines a Stage 3 (aggressive) lesion?

Malignant infantile osteopetrosis is an autosomal recessive disorder characterized by non-functioning osteoclasts and a lack of medullary canal formation. The most common genetic mutation responsible for this severe phenotype involves a gene encoding for which of the following?

A 14-year-old boy presents with a diaphyseal femur lesion exhibiting an 'onion-skin' periosteal reaction. A core biopsy confirms a small round blue cell tumor. Which of the following chromosomal translocations is most characteristic of this malignancy?

A 25-year-old male presents with a slowly enlarging mass near his knee. Biopsy confirms synovial sarcoma. Which of the following chromosomal translocations is diagnostic for this tumor?

A 15-year-old boy presents with a diaphyseal lesion of the femur. Biopsy reveals small round blue cells. The genetic anomaly most commonly associated with this tumor results in the formation of which fusion protein?

A 28-year-old male presents with a slow-growing soft tissue mass deep in the popliteal fossa. Biopsy reveals a biphasic pattern consisting of spindle cells and epithelial cells. Cytogenetic analysis is most likely to reveal which of the following translocations?

A 15-year-old boy presents with a permeative, lytic lesion in the metadiaphysis of the proximal tibia associated with an 'onion-skin' periosteal reaction. If this lesion is confirmed as Ewing sarcoma, which cytogenetic abnormality is most likely present?