Menu

10. Pathology and Oncology MCQs

Practice Set 28 of 351

This practice set contains high-yield board review questions covering key concepts in 10. Pathology and Oncology. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 541

Topic: 10. Pathology and Oncology

A 15-year-old boy has a large mass underneath the toenail of his great toe. His nail is raised and ulceration is present. The plain radiograph is shown in Slide 1, and biopsy specimens are shown in Slides 2, 3, and 4. The most likely diagnosis is:

. Low-grade osteosarcoma
. High-grade osteosarcoma
. Fibrosarcoma
. Parosteal osteosarcoma
. Subungual exostosis

Correct Answer & Explanation

. Subungual exostosis

Explanation

The plain radiograph shows a large bone lesion arising from the dorsal surface of the distal phalanx. This radiographic appearance is characteristic of a subungual exostosis. Osteochondromas do not occur in the distal phalanx, and there is no communication between the lesion and the medullary cavity.The biopsy specimens show the new bone formation and a fibroblastic stroma, which can be confused with osteosarcoma. The diagnosis is subungual exostosis and the treatment is simple excision.

Question 542

Topic: 10. Pathology and Oncology

A 15-year-old boy has a large mass underneath the toenail of his great toe. His nail is raised and ulceration is present. The plain radiograph is shown in Slide 1, and biopsy specimens are shown in Slides 2, 3, and 4. Which of the following is the best form o treatment:

. Toe amputation
. Preoperative chemotherapy followed by toe amputation
. External beam irradiation
. External beam irradiation and chemotherapy
. Simple excision

Correct Answer & Explanation

. Simple excision

Explanation

The plain radiograph shows a large bone lesion arising from the dorsal surface of the distal phalanx. This radiographic appearance is characteristic of a subungual exostosis. Osteochondromas do not occur in the distal phalanx, and there is no communication between the lesion and the medullary cavity. The biopsy specimens show the new bone formation and a fibroblastic stroma, which can be confused with osteosarcoma. The diagnosis is subungual exostosis and the treatment is simple excision.

Question 543

Topic: 10. Pathology and Oncology

A 15-year-old boy has a large mass underneath the toenail of his great toe. His nail is raised and ulceration is present. The plain radiograph is shown in Slide 1, and biopsy specimens are shown in Slides 2, 3, and 4. Which of the following best describes this condition:

. Low-grade malignancy
. High-grade malignancy
. Inactive benign neoplasm
. Aggressive benign neoplasm
. Benign reactive condition (non-neoplastic)

Correct Answer & Explanation

. Benign reactive condition (non-neoplastic)

Explanation

The plain radiograph shows a large bone lesion arising from the dorsal surface of the distal phalanx. This radiographic appearance is characteristic of a subungual exostosis. Osteochondromas do not occur in the distal phalanx, and there is no communication between the lesion and the medullary cavity.The biopsy specimens show the new bone formation and a fibroblastic stroma, which can be confused with osteosarcoma. The diagnosis is subungual exostosis and the treatment is simple excision.

Question 544

Topic: 10. Pathology and Oncology

A 12-year-old boy presents with knee pain and a destructive, permeative diaphyseal lesion in the femur with a large soft tissue mass. Biopsy reveals small round blue cells. Which chromosomal translocation is most characteristic of this tumor?

. t(11;22)
. t(X;18)
. t(9;22)
. t(2;13)
. t(12;16)

Correct Answer & Explanation

. t(11;22)

Explanation

The scenario describes Ewing sarcoma, characterized by a permeative diaphyseal lesion and small round blue cells on histology. The classic chromosomal translocation is t(11;22)(q24;q12), which results in the EWS-FLI1 fusion protein.

Question 545

Topic: 10. Pathology and Oncology

In a patient diagnosed with high-grade conventional intramedullary osteosarcoma, which of the following represents the most significant prognostic factor for long-term survival?

. Patient age at diagnosis
. Tumor volume at diagnosis
. Histologic response to neoadjuvant chemotherapy
. Specific histologic subtype (e.g., osteoblastic vs fibroblastic)
. Proximal versus distal limb location

Correct Answer & Explanation

. Histologic response to neoadjuvant chemotherapy

Explanation

The degree of tumor necrosis following neoadjuvant chemotherapy (histologic response) is the single most important prognostic factor for overall survival in patients with high-grade osteosarcoma. Greater than 90% necrosis denotes a favorable response.

Question 546

Topic: 10. Pathology and Oncology

A biopsy of a destructive, lytic bone lesion in the diaphysis of the femur of a 15-year-old boy shows sheets of uniform, small round blue cells. Cytogenetic analysis reveals a t(11;22) translocation. What is the most likely diagnosis?

. Osteosarcoma
. Ewing sarcoma
. Chondrosarcoma
. Multiple myeloma

Correct Answer & Explanation

. Ewing sarcoma

Explanation

Ewing sarcoma is classically characterized by small round blue cells on histology and the t(11;22) chromosomal translocation, which results in the EWS-FLI1 fusion protein.

Question 547

Topic: 10. Pathology and Oncology

A 53-year-old diabetic patient presents with an ulcer on the plantar aspect of the foot that has been present for 2 years. There is mild serous drainage; bone is not exposed. The recommended treatment is:

. Wound culture, oral antibiotic therapy, and debridement
. Wound culture, intravenous antibiotic therapy, and debridement
. Debridement and split thickness skin grafting
. Debridement, bone biopsy, and appropriate organism specific antibiotic therapy
. Debridement and application of a total contact cast

Correct Answer & Explanation

. Debridement and application of a total contact cast

Explanation

This is a typical chronic plantar neuropathic ulcer. There is no evidence of acute infection by appearance, and therefore, no cultures or antibiotic therapy is required. Debridement of the ulcer margin only is useful followed by application of a total contact cast. Split thickness skin grafting is never indicated on the plantar foot surface in the setting of neuropathic ulceration.

Question 548

Topic: 10. Pathology and Oncology

A patient wants a below the knee amputation. As an alternative, you recommend a Syme amputation. What is the most relevant factor that would contraindicate performing a Syme amputation:

. A metastatic tumor to the forefoot
. Severe infection in the foot
. A primary tumor in the forefoot and midfoot
. Peripheral vascular disease
. Trauma to the hindfoot

Correct Answer & Explanation

. Peripheral vascular disease

Explanation

Although the Syme amputation was once popular because it allowed patients to ambulate for short distances (e.g., around their house) without using a prosthesis, surgeons now perform more below the knee amputations because of newer prosthetic designs. The Syme procedure still remains in our surgical armamentarium. The only factor listed in the answer choices that may preclude amputation at this level is peripheral vascular disease. A more important factor that would contraindicate performing a Syme amputation is perfusion to the heel pad.

Question 549

Topic: Bone Tumors

A 15-year-old male presents with worsening distal femur pain. Radiographs reveal a mixed lytic/sclerotic lesion with a "sunburst" periosteal reaction. Staging studies are performed. What is the most common site of metastasis for this primary bone tumor?

. Liver
. Brain
. Lungs
. Lymph nodes
. Spine

Correct Answer & Explanation

. Lungs

Explanation

The clinical and radiographic presentation is classic for osteosarcoma. The lungs are the most common site of initial metastasis for osteosarcoma, making chest CT a critical component of staging.

Question 550

Topic: 10. Pathology and Oncology

A 15-year-old boy is diagnosed with a conventional high-grade intramedullary osteosarcoma of the distal femur. He undergoes neoadjuvant chemotherapy followed by wide surgical resection. Which of the following is the most important prognostic factor for his overall survival?

. Initial tumor volume on MRI
. Patient age at the time of diagnosis
. Serum alkaline phosphatase levels at presentation
. Percentage of tumor necrosis mapped on the resected specimen
. Specific surgical approach used for limb salvage

Correct Answer & Explanation

. Percentage of tumor necrosis mapped on the resected specimen

Explanation

The histologic response to neoadjuvant chemotherapy, defined by the percentage of tumor necrosis in the resected specimen (Huvos grading), is the single most significant prognostic indicator for overall survival in osteosarcoma.

Question 551

Topic: 10. Pathology and Oncology

A 15-year-old boy presents with severe knee pain that awakens him at night. Plain radiographs reveal a mixed lytic and sclerotic lesion in the distal femoral metaphysis with a prominent 'sunburst' periosteal reaction. Core biopsy confirms high-grade intramedullary osteosarcoma. What is the standard sequence of treatment?

. Neoadjuvant chemotherapy followed by wide surgical resection and adjuvant chemotherapy
. Wide surgical resection alone with wide margins
. Radiation therapy followed by wide surgical resection
. Primary above-knee amputation alone
. Adjuvant chemotherapy followed by primary radiation therapy

Correct Answer & Explanation

. Neoadjuvant chemotherapy followed by wide surgical resection and adjuvant chemotherapy

Explanation

The current standard of care for high-grade intramedullary osteosarcoma includes neoadjuvant chemotherapy, wide surgical resection (limb salvage if possible), and adjuvant chemotherapy. Osteosarcoma is generally radioresistant, making radiation therapy a non-primary modality.

Question 552

Topic: Bone Tumors

A 15-year-old boy presents with progressive knee pain and swelling for 2 months. Radiographs of the distal femur show a mixed lytic and blastic lesion, cortical destruction, and a Codman triangle. After staging, what is the most appropriate next step in management?

. Immediate transfemoral amputation
. Wide surgical excision alone
. Neoadjuvant chemotherapy followed by wide excision
. Radiation therapy followed by wide excision
. Intralesional curettage and bone grafting

Correct Answer & Explanation

. Neoadjuvant chemotherapy followed by wide excision

Explanation

The clinical and radiographic findings are classic for osteosarcoma. The standard of care involves neoadjuvant chemotherapy, followed by wide surgical resection (limb salvage), and subsequent adjuvant chemotherapy.

Question 553

Topic: 10. Pathology and Oncology

A 14-year-old boy presents with progressive knee pain. Radiographs demonstrate a destructive metaphyseal lesion of the distal femur with a sunburst periosteal reaction.

Biopsy confirms high-grade osteosarcoma. Which of the following factors is the most important prognostic indicator for his long-term survival?

. The exact anatomic location of the tumor
. The presence of a Codman triangle on plain radiographs
. The degree of tumor necrosis following neoadjuvant chemotherapy
. The patient's age and gender at the time of diagnosis
. The specific histologic subtype of osteosarcoma

Correct Answer & Explanation

. The degree of tumor necrosis following neoadjuvant chemotherapy

Explanation

In high-grade extremity osteosarcoma, the most significant prognostic factor for survival is the histologic response to neoadjuvant chemotherapy. Greater than 90% tumor necrosis is considered a good response and correlates with improved long-term outcomes.

Question 554

Topic: 10. Pathology and Oncology

A 15-year-old boy presents with progressive pain and swelling in his distal femur. Radiographs reveal a mixed lytic and sclerotic lesion with cortical destruction and a "sunburst" periosteal reaction. Biopsy confirms high-grade osteosarcoma. What is the most important prognostic factor for his overall survival?

. Histologic subtype of the tumor
. Extent of tumor necrosis following neoadjuvant chemotherapy
. Size of the soft tissue mass at presentation
. Serum alkaline phosphatase level
. Proximity of the tumor to the physis

Correct Answer & Explanation

. Extent of tumor necrosis following neoadjuvant chemotherapy

Explanation

The percentage of tumor necrosis following neoadjuvant chemotherapy is the most reliable prognostic indicator for patients with high-grade osteosarcoma. Achieving greater than 90% necrosis is strongly associated with improved long-term survival.

Question 555

Topic: 10. Pathology and Oncology
Which of the following stimulates aggrecan core protein and glycosaminoglycan synthesis?
. Static compression within the physiologic range
. Chronic compressive loads outside the physiologic range
. Cyclic intermittent hydrostatic pressure and compressive strain
. Interleukin I and matrix metalloproteinases
. Tumor necrosis factor

Correct Answer & Explanation

. Cyclic intermittent hydrostatic pressure and compressive strain

Explanation

Cyclic compressive loads have the ability to stimulate matrix synthesis—aggrecan core protein and the glycosaminoglycans. The other responses are catabolic toward the cartilage—they break the cartilage down: Tumor necrosis factor, Interleukin I, matrix metalloproteinases, chronic compressive loads outside the physiologic range, and static compression (e.g., putting a patient in a cast).

Question 556

Topic: 10. Pathology and Oncology

A 43-year-old woman has had a 2-year history of ankle pain. Her ankle pain is associated with swelling, decreased activities, and limited range of motion. Upon examination, diffuse warmth and swelling of the ankle are noted. Radiographs and a clinical picture are presented. The most likely diagnosis is:

. Rheumatoid arthritis
. Gout
. Septic arthritis
. Synovial sarcoma
. Pigmented villonodular synovitis (PVNS)

Correct Answer & Explanation

. Rheumatoid arthritis

Explanation

Although pigmented villonodular synovitis (PVNS), infection, or gout may cause inflammatory changes on both sides of the ankle joint, the most likely cause of this inflammatory arthropathy is rheumatoid arthritis. Note the cystic changes, the synovial hypertrophy, and the joint inflammation.

Question 557

Topic: Bone Tumors

A 16-year-old male presents with knee pain. Radiographs show an aggressive, bone-forming distal femoral metaphyseal lesion with periosteal reaction (Codman's triangle). Which is the most common site of metastasis for this suspected malignancy?

. Liver
. Brain
. Lungs
. Spine
. Lymph nodes

Correct Answer & Explanation

. Lungs

Explanation

The clinical and radiographic picture strongly suggests conventional osteosarcoma. The lungs are the most common site for distant hematogenous metastasis in osteosarcoma.

Question 558

Topic: Bone Tumors

Which of the following is the most frequent primary site of involvement for classic high-grade intramedullary osteosarcoma in the pediatric population?

. Proximal humerus
. Proximal femur
. Distal femur
. Proximal tibia
. Distal tibia

Correct Answer & Explanation

. Distal femur

Explanation

Osteosarcoma most commonly affects the metaphyses of long bones where growth is most active. The distal femur is the single most common site, followed by the proximal tibia and the proximal humerus.

Question 559

Topic: 10. Pathology and Oncology

A 55-year-old male presents with a painless, enlarging mass in the proximal humerus. Biopsy reveals a malignant cartilage-forming tumor with permeation of the host bone trabeculae. What is the most appropriate initial treatment for a conventional grade II chondrosarcoma?

. Neoadjuvant chemotherapy followed by wide resection
. External beam radiation therapy alone
. Intralesional curettage and cementation
. Wide surgical resection alone
. Radiofrequency ablation

Correct Answer & Explanation

. Wide surgical resection alone

Explanation

Conventional intermediate and high-grade chondrosarcomas are typically resistant to both chemotherapy and radiation. Wide surgical resection with negative margins is the standard of care to maximize survival and minimize local recurrence.

Question 560

Topic: 10. Pathology and Oncology

A 55-year-old aquarium enthusiast presents with a chronic, slowly enlarging nodular lesion on his right hand that recently ulcerated. He reports a mild, aching pain but no systemic symptoms. Cultures from a biopsy are optimally grown at 30 degrees Celsius. What is the most likely causative organism?

. Sporothrix schenckii
. Staphylococcus aureus
. Mycobacterium marinum
. Candida albicans
. Pseudomonas aeruginosa

Correct Answer & Explanation

. Mycobacterium marinum

Explanation

Mycobacterium marinum is an atypical mycobacterium found in aquatic environments, classically presenting as a "fish tank granuloma" in aquarium workers or fishermen. It requires lower incubation temperatures (30°C) to grow in culture.

Test Yourself

Switch to an interactive, timed exam simulation to truly master this topic.

On this Page