Menu

10. Pathology and Oncology MCQs

Practice Set 294 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 5861

Topic: 10. Pathology and Oncology

A 15-year-old boy presents with progressive knee pain and a palpable mass. Biopsy reveals small round blue cells. The provided radiograph is shown.

Which chromosomal translocation is most characteristically associated with this pathology?

. t(11;22) EWS-FLI1
. t(9;22) BCR-ABL
. t(X;18) SYT-SSX
. t(12;16) FUS-DDIT3
. t(2;13) PAX3-FOXO1

Correct Answer & Explanation

. t(11;22) EWS-FLI1

Explanation

The clinical picture and image describe Ewing sarcoma, an aggressive primary bone tumor. Over 85% of Ewing sarcomas are characterized by the t(11;22)(q24;q12) translocation, which forms the EWS-FLI1 fusion gene.

Question 5862

Topic: 10. Pathology and Oncology

A 12-year-old girl is diagnosed with the bone lesion shown in the provided imaging.

Immunohistochemistry of the biopsy specimen is most likely to be strongly positive for which of the following cell surface markers?

. CD99 (MIC2)
. Cytokeratin
. S-100
. Desmin
. MyoD1

Correct Answer & Explanation

. CD99 (MIC2)

Explanation

The image shows a diaphyseal permeative lesion with periosteal reaction typical of Ewing sarcoma. Immunohistochemistry for Ewing sarcoma classically exhibits strong, diffuse membranous staining for CD99 (MIC2).

Question 5863

Topic: 10. Pathology and Oncology

An 11-year-old boy presents with progressive leg pain and fever. Radiographs show a permeative diaphyseal lesion with an "onion skin" periosteal reaction. Biopsy confirms the diagnosis.

Which genetic translocation is most commonly associated with this pathology?

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

Correct Answer & Explanation

. t(11;22)

Explanation

The clinical presentation and imaging are classic for Ewing sarcoma. The t(11;22) translocation resulting in the EWS-FLI1 fusion protein is found in approximately 85% of Ewing sarcoma cases.

Question 5864

Topic: 10. Pathology and Oncology

A 14-year-old female is diagnosed with Ewing sarcoma of the distal femur.

Which of the following is the most important prognostic factor for her overall survival?

. Tumor size at presentation
. Histological grade
. Presence of distant metastasis at diagnosis
. Age at diagnosis
. Gender

Correct Answer & Explanation

. Presence of distant metastasis at diagnosis

Explanation

The presence of distant metastasis (most commonly to lungs or bone) at the time of diagnosis is the single most important adverse prognostic factor in Ewing sarcoma. Patients with metastatic disease have a significantly lower 5-year survival rate.

Question 5865

Topic: 10. Pathology and Oncology
A 15-year-old male presents with persistent distal femoral pain. Biopsy reveals high-grade osteosarcoma. Following neoadjuvant chemotherapy, surgical resection is performed. What percentage of tumor necrosis in the resection specimen is required to be considered a favorable response?
. > 50%
. > 70%
. > 80%
. > 90%
. > 99%

Correct Answer & Explanation

. > 90%

Explanation

In high-grade osteosarcoma, a histologic response to neoadjuvant chemotherapy of greater than 90% tumor necrosis (Huvos grade III or IV) is considered favorable. This metric is a critical predictor of long-term survival.

Question 5866

Topic: 10. Pathology and Oncology

A 32-year-old female presents with an eccentric, lytic, epiphyseal lesion in the proximal tibia. Biopsy confirms Giant Cell Tumor (GCT). Which targeted medical therapy has proven effective as a neoadjuvant treatment for advanced or unresectable GCTs?

. Imatinib
. Denosumab
. Doxorubicin
. Bortezomib
. Methotrexate

Correct Answer & Explanation

. Denosumab

Explanation

Denosumab, a monoclonal antibody against RANKL, is highly effective in treating Giant Cell Tumors of bone. It inhibits osteoclast-like giant cells, leading to tumor consolidation.

Question 5867

Topic: Bone Tumors

A 19-year-old male reports persistent nocturnal thigh pain that is completely relieved by ibuprofen. Imaging reveals a 7mm radiolucent nidus surrounded by reactive sclerosis in the femoral diaphysis. What is the standard, minimally invasive definitive treatment?

. En bloc resection
. Curettage and bone grafting
. Radiofrequency ablation (RFA)
. Radiation therapy
. Long-term narcotic pain management

Correct Answer & Explanation

. Radiofrequency ablation (RFA)

Explanation

Radiofrequency ablation (RFA) is the current gold standard and least invasive definitive treatment for an osteoid osteoma. It provides excellent success rates with minimal morbidity compared to open surgical resection.

Question 5868

Topic: 10. Pathology and Oncology

In the multidisciplinary management of Ewing sarcoma of the extremity, what is the standard sequence of treatment?

. Primary surgical resection followed by radiation
. Neoadjuvant chemotherapy, local control (surgery and/or radiation), followed by adjuvant chemotherapy
. Primary radiation therapy followed by adjuvant chemotherapy
. Neoadjuvant radiation, surgery, followed by observation
. Primary amputation in all cases

Correct Answer & Explanation

. Neoadjuvant chemotherapy, local control (surgery and/or radiation), followed by adjuvant chemotherapy

Explanation

The standard of care for Ewing sarcoma includes neoadjuvant chemotherapy to shrink the tumor and treat micrometastases. This is followed by local control via surgery or radiation, and then adjuvant chemotherapy.

Question 5869

Topic: 10. Pathology and Oncology

An 18-year-old male presents with a 6-month history of painful scoliosis. Imaging reveals a 3.5 cm expansile, radiolucent lesion in the posterior elements of L4. He reports the pain is dull, continuous, and not significantly relieved by NSAIDs. What is the most likely diagnosis?

. Osteoid osteoma
. Aneurysmal bone cyst
. Ewing sarcoma
. Osteoblastoma
. Giant cell tumor

Correct Answer & Explanation

. Osteoblastoma

Explanation

Osteoblastomas are benign bone forming tumors that frequently occur in the posterior elements of the spine causing painful scoliosis. Unlike osteoid osteomas, they are typically larger than 2 cm, locally aggressive, and the pain is less predictably relieved by NSAIDs.

Question 5870

Topic: 10. Pathology and Oncology

A 10-year-old boy presents with progressive thigh pain and low-grade fever. Radiographs and subsequent MRI demonstrate a large permeative lesion in the femoral diaphysis.

Biopsy confirms Ewing sarcoma. Aside from the presence of metastasis, which of the following is an independent poor prognostic factor for survival?

. Diaphyseal location
. Patient age less than 12 years
. Elevated alkaline phosphatase
. Tumor volume less than 100 mL
. Pelvic tumor location

Correct Answer & Explanation

. Pelvic tumor location

Explanation

In Ewing sarcoma, the presence of metastasis at presentation is the most significant poor prognostic factor. Other independent predictors of poor outcome include a pelvic primary tumor location, tumor volume greater than 100 mL, and poor histologic response to chemotherapy.

Question 5871

Topic: 10. Pathology and Oncology
A 60-year-old male presents with deep pelvic pain. Imaging reveals a 10 cm destructive iliac wing lesion with intralesional stippled and "popcorn" calcifications. Core biopsy confirms a Grade II conventional chondrosarcoma. What is the most appropriate definitive management?
. Wide surgical resection
. Neoadjuvant chemotherapy followed by wide resection
. Intralesional curettage and cementation
. Definitive external beam radiation
. Radiofrequency ablation

Correct Answer & Explanation

. Wide surgical resection

Explanation

Conventional chondrosarcomas are typically resistant to both chemotherapy and radiation therapy. The mainstay of treatment for intermediate and high-grade (Grade II and III) chondrosarcomas is wide surgical excision with negative margins.

Question 5872

Topic: 10. Pathology and Oncology
A 14-year-old male undergoes 10 weeks of neoadjuvant chemotherapy for an osteosarcoma of the distal femur, followed by wide surgical resection. Histologic mapping of the resected specimen demonstrates 95% tumor necrosis. What is the significance of this finding according to the Huvos grading system?
. It represents a Grade I response, warranting a change in postoperative chemotherapy
. It represents a Grade II response, indicating chemoresistance
. It represents a Grade III response, indicating a poor overall prognosis
. It represents a Grade IV response, requiring postoperative radiation
. It represents a good response (Grade III), associated with an improved overall survival prognosis

Correct Answer & Explanation

. It represents a good response (Grade III), associated with an improved overall survival prognosis

Explanation

In the Huvos grading system for osteosarcoma, a "good response" to neoadjuvant chemotherapy is defined as greater than 90% tumor necrosis (Grade III is 90-99%, Grade IV is 100%). This is a strong independent predictor of improved long-term disease-free survival.

Question 5873

Topic: 10. Pathology and Oncology

A 9-year-old girl presents with an aggressive lytic lesion of the fibula.

Biopsy demonstrates uniform sheets of small round blue cells. Cytogenetics reveals a t(11;22) translocation. Which immunohistochemical marker is characteristically strongly positive in this tumor?

. Desmin
. MyoD1
. CD99 (MIC2)
. Cytokeratin
. S-100

Correct Answer & Explanation

. CD99 (MIC2)

Explanation

Ewing sarcoma is a small round blue cell tumor characterized by the t(11;22) translocation, resulting in the EWS-FLI1 fusion protein. Immunohistochemistry classically shows strong, diffuse membranous staining for CD99 (MIC2).

Question 5874

Topic: 10. Pathology and Oncology

A 15-year-old boy presents with progressive diaphyseal thigh pain. Radiographs demonstrate the lesion shown below.

A biopsy confirms a CD99 positive small round blue cell tumor. What is the most critical prognostic factor for overall survival in this patient?

. Presence of metastases at diagnosis
. Size of the primary tumor
. Histologic grade
. Patient age
. Type of EWS-FLI1 fusion transcript

Correct Answer & Explanation

. Presence of metastases at diagnosis

Explanation

The presence of distant metastases at the time of diagnosis is the most important independent prognostic factor for overall survival in patients with Ewing sarcoma. While tumor volume and response to chemotherapy also influence prognosis, metastatic disease lowers the survival rate significantly.

Question 5875

Topic: 10. Pathology and Oncology

A 16-year-old girl is undergoing treatment for a conventional high-grade osteosarcoma of the distal femur. Following neoadjuvant chemotherapy, she undergoes wide surgical resection. The pathology report indicates 95% tumor necrosis. What does this histologic finding predict?

. A higher risk for local recurrence
. Necessity for immediate amputation
. Decreased event-free survival compared to a patient with 50% necrosis
. Favorable overall prognosis and response to systemic therapy
. Resistance to adjuvant methotrexate

Correct Answer & Explanation

. Favorable overall prognosis and response to systemic therapy

Explanation

The degree of tumor necrosis following neoadjuvant chemotherapy is one of the most reliable prognostic indicators in osteosarcoma. Tumor necrosis of 90% or greater (a "good response") is strongly associated with improved overall survival and event-free survival.

Question 5876

Topic: 10. Pathology and Oncology

A 68-year-old male with a history of prostate cancer treated with radiation therapy and androgen deprivation therapy presents with acute onset severe back pain, new neurological deficits including bilateral leg weakness (3/5) and saddle anesthesia. MRI reveals a compression fracture at T12 with significant retropulsion causing severe spinal canal stenosis. What is the most urgent next step in management?

. Initiate high-dose corticosteroids
. Refer for palliative radiation therapy
. Perform emergent surgical decompression and stabilization
. Administer IV bisphosphonates
. Obtain a bone scan for metastatic workup

Correct Answer & Explanation

. Initiate high-dose corticosteroids

Explanation

The most urgent next step in a patient with suspected metastatic spinal cord compression (SCC) is to initiate high-dose corticosteroids, such as dexamethasone. This helps reduce peritumoral edema, which can alleviate neurological symptoms and buy time for definitive diagnosis and treatment planning. While emergent surgical decompression and stabilization may be indicated, steroids are typically administered first, often even prior to definitive imaging if SCC is strongly suspected clinically. Radiation therapy is often used in conjunction with surgery or as primary treatment for radiosensitive tumors, but steroids provide more immediate relief. Bisphosphonates are for long-term bone protection and pain, not acute SCC. A bone scan is part of workup, but not the most urgent immediate management for acute neurological deficit.

Question 5877

Topic: 10. Pathology and Oncology

Which of the following statements regarding osteosarcoma is FALSE?

. It is the most common primary malignant bone tumor in children and adolescents.
. The most common sites are the metaphyses of long bones, particularly around the knee.
. It typically presents with a lytic lesion with a 'sunburst' or Codman's triangle appearance on radiographs.
. Pulmonary metastasis is the most common site of distant spread.
. Chemotherapy is only indicated for metastatic disease.

Correct Answer & Explanation

. Chemotherapy is only indicated for metastatic disease.

Explanation

Chemotherapy is a crucial component of treatment for nearly all osteosarcomas, including localized disease. It is administered both pre-operatively (neoadjuvant) and post-operatively (adjuvant) to improve limb salvage rates, reduce tumor burden, treat micrometastatic disease, and assess tumor response. Therefore, the statement that chemotherapy is only indicated for metastatic disease is false. All other statements are true: osteosarcoma is the most common primary malignant bone tumor in children/adolescents, often found in long bone metaphyses, characterized by classic radiographic features, and most commonly metastasizes to the lungs.

Question 5878

Topic: 10. Pathology and Oncology

Which of the following is the most common primary malignant bone tumor in adults?

. Osteosarcoma
. Ewing sarcoma
. Chondrosarcoma
. Multiple myeloma
. Fibrosarcoma

Correct Answer & Explanation

. Multiple myeloma

Explanation

Multiple myeloma is the most common primary malignant bone tumor in adults. It is a malignancy of plasma cells that arises in the bone marrow and typically presents with multifocal lytic lesions throughout the skeleton. While osteosarcoma and Ewing sarcoma are common in children and adolescents, and chondrosarcoma is another primary adult bone tumor, multiple myeloma has a higher incidence overall in adults. Fibrosarcoma is a very rare primary bone tumor.

Question 5879

Topic: 10. Pathology and Oncology

Which of the following describes a typical radiographic appearance of Ewing sarcoma?

. Geographic lytic lesion with a narrow zone of transition.
. 'Sunburst' appearance with periosteal reaction and soft tissue mass.
. 'Onion skin' periosteal reaction.
. Ground-glass matrix with a shepherd's crook deformity.
. Popcorn calcification within the lesion.

Correct Answer & Explanation

. 'Onion skin' periosteal reaction.

Explanation

Ewing sarcoma is classically associated with an 'onion skin' (lamellated) periosteal reaction on radiographs, which represents layers of new bone formation. This, along with a permeative or moth-eaten lytic pattern, indicates a highly aggressive tumor. While a soft tissue mass is often present, the 'sunburst' appearance is more characteristic of osteosarcoma. Geographic lytic lesions with a narrow zone of transition are seen in benign lesions. Ground-glass matrix with a shepherd's crook deformity is characteristic of fibrous dysplasia. Popcorn calcification is seen in enchondromas or chondrosarcomas.

Question 5880

Topic: 10. Pathology and Oncology

Which of the following is the most common benign bone tumor?

. Osteoid osteoma
. Enchondroma
. Osteochondroma
. Non-ossifying fibroma
. Giant cell tumor

Correct Answer & Explanation

. Osteochondroma

Explanation

Osteochondroma (exostosis) is the most common benign bone tumor. It is a cartilage-capped bony projection on the external surface of bone, arising from the metaphysis of long bones, typically around the knee. Non-ossifying fibroma (fibrous cortical defect) is also very common but often an incidental finding and a developmental anomaly rather than a true neoplasm. Enchondroma and osteoid osteoma are common but less so than osteochondroma. Giant cell tumor is locally aggressive but less common than osteochondroma.

Test Yourself

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

On this Page