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10. Pathology and Oncology MCQs

Practice Set 114 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 2261

Topic: 10. Pathology and Oncology

A 55-year-old man presents with an insidious onset of dull, aching shoulder pain. Radiographs demonstrate a calcified intramedullary lesion in the proximal humerus with endosteal scalloping involving 80% of the cortical thickness. Biopsy confirms a low-grade chondrosarcoma. What is the most appropriate definitive management?

. Observation with serial radiographs every 6 months
. Intralesional curettage with phenol adjuvant and bone grafting
. Wide surgical resection with anatomic reconstruction
. Neoadjuvant chemotherapy followed by wide resection
. Primary radiation therapy

Correct Answer & Explanation

. Wide surgical resection with anatomic reconstruction

Explanation

The clinical and radiographic presentation is classic for a primary central chondrosarcoma. Unlike enchondromas, chondrosarcomas frequently exhibit endosteal scalloping greater than 2/3 of the cortical thickness and present with mechanical or biologic pain. Chondrosarcomas are notoriously resistant to both chemotherapy and radiation therapy. The mainstay of treatment for conventional chondrosarcoma is wide surgical resection. While extended intralesional curettage may be considered for some appendicular atypical cartilaginous tumors (Grade 1), wide resection is the gold standard, especially with significant endosteal scalloping and risk of cortical breakthrough.

Question 2262

Topic: 10. Pathology and Oncology
A 15-year-old male undergoes surgical resection of a conventional osteosarcoma of the distal femur following a 10-week course of neoadjuvant chemotherapy. According to the Huvos grading system, which of the following histologic findings in the resected specimen represents the most significant prognostic factor for long-term survival?
. Presence of a dense chondroblastic matrix
. Greater than 90% tumor necrosis
. Complete absence of mitotic figures in the remaining viable tumor
. Tumor encapsulation by a thick periosteal shell
. Less than 10% cortical breakthrough

Correct Answer & Explanation

. Greater than 90% tumor necrosis

Explanation

The most important prognostic factor for overall survival in patients with conventional high-grade osteosarcoma is the histologic response to neoadjuvant chemotherapy. A "good response," defined by the Huvos grading system as greater than 90% tumor necrosis (Grade III or IV), correlates with a significantly improved prognosis and long-term survival.

Question 2263

Topic: 10. Pathology and Oncology
A 60-year-old male presents with a large, destructive mass in the right ilium. CT scan reveals a lytic lesion with intralesional 'rings and arcs' calcification. Core needle biopsy confirms a Grade II conventional chondrosarcoma. Which of the following is the most appropriate treatment strategy?
. Wide surgical excision alone
. Intralesional curettage with adjuvant cryotherapy
. Neoadjuvant chemotherapy followed by wide surgical excision
. Wide surgical excision followed by external beam radiation therapy
. Primary radiation therapy

Correct Answer & Explanation

. Neoadjuvant chemotherapy followed by wide surgical excision

Explanation

Conventional chondrosarcomas are notoriously resistant to both chemotherapy and radiation therapy due to their poor vascularity, slow growth, and high extracellular matrix content. Intermediate (Grade II) and high-grade (Grade III) chondrosarcomas of the pelvis require wide surgical excision with negative margins as the definitive treatment. Intralesional curettage is reserved for benign or low-grade (Grade I) cartilaginous tumors in the appendicular skeleton.

Question 2264

Topic: 10. Pathology and Oncology

A 25-year-old male presents with a slow-growing, painful mass around the posterolateral knee. MRI reveals a well-circumscribed, soft tissue mass near the joint without bone involvement. Core needle biopsy demonstrates a biphasic histologic pattern with both epithelial and spindle cells. Which of the following specific chromosomal translocations is most characteristic of this patient's diagnosis?

. t(11;22)(q24;q12)
. t(X;18)(p11;q11)
. t(12;16)(q13;p11)
. t(9;22)(q22;q12)
. t(2;13)(q35;q14)

Correct Answer & Explanation

. t(X;18)(p11;q11)

Explanation

The clinical scenario and biphasic histology (epithelial and spindle cells) are classic for Synovial Sarcoma. The hallmark cytogenetic abnormality for synovial sarcoma is the t(X;18)(p11;q11) translocation, which results in the fusion of the SYT gene on chromosome 18 with one of the SSX genes (SSX1, SSX2, or SSX4) on the X chromosome.Option 0 is characteristic of Ewing sarcoma. Option 2 is associated with myxoid liposarcoma. Option 3 is seen in extraskeletal myxoid chondrosarcoma. Option 4 is characteristic of alveolar rhabdomyosarcoma.

Question 2265

Topic: 10. Pathology and Oncology
A 16-year-old male is diagnosed with a high-grade intramedullary osteosarcoma of the distal femur. Staging studies show no clinically detectable pulmonary or osseous metastases. He is initiated on a standard neoadjuvant chemotherapy protocol, followed by limb-salvage wide resection. Which of the following factors obtained from the resected specimen is the most significant prognostic indicator for his long-term survival?
. Tumor volume greater than 150 cubic centimeters
. Histologic subtype being osteoblastic rather than chondroblastic
. Percentage of tumor necrosis in response to neoadjuvant chemotherapy
. Microvascular density of the tumor margins
. Distance of the tumor margin from the articular cartilage

Correct Answer & Explanation

. Percentage of tumor necrosis in response to neoadjuvant chemotherapy

Explanation

In non-metastatic high-grade osteosarcoma, the degree of tumor necrosis following neoadjuvant chemotherapy is the single most powerful prognostic factor for long-term survival. A good response is typically defined as 90% or greater tumor necrosis (Huvos grade III or IV). Patients with less than 90% necrosis (poor responders) have a significantly higher risk of local recurrence and systemic metastasis, resulting in lower overall survival.

Question 2266

Topic: 10. Pathology and Oncology

A 14-year-old boy presents with progressive thigh pain. Radiographs demonstrate a large, permeative, lytic lesion in the diaphysis of the femur with an extensive 'onion-skin' periosteal reaction.

A core needle biopsy is performed, and histology reveals densely packed uniform small round blue cells with scant cytoplasm. Immunohistochemistry is strongly positive for CD99. Which of the following chromosomal translocations is most frequently associated with the pathogenesis of this tumor?

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

Correct Answer & Explanation

. t(11;22)

Explanation

The clinical presentation, 'onion-skin' periosteal reaction, small round blue cell histology, and CD99 positivity are hallmark features of Ewing Sarcoma. Ewing sarcoma is a primitive neuroectodermal tumor defined by translocations involving the EWSR1 gene on chromosome 22. The most common translocation, found in approximately 85% of cases, is t(11;22)(q24;q12), which fuses EWSR1 with the FLI1 gene. Option 1 is synovial sarcoma, Option 2 is myxoid liposarcoma, Option 3 is extraskeletal myxoid chondrosarcoma, and Option 4 is alveolar rhabdomyosarcoma.

Question 2267

Topic: 10. Pathology and Oncology

A 15-year-old male presents with deep, aching pain in his distal femur. Radiographs reveal an aggressive lytic lesion with a 'sunburst' periosteal reaction. Biopsy confirms a high-grade intramedullary osteosarcoma. He undergoes neoadjuvant chemotherapy followed by wide surgical resection. Which of the following is the most significant prognostic factor for long-term survival in this patient?

. Age at presentation
. Gender of the patient
. Histologic response to neoadjuvant chemotherapy
. Presence of specific p53 mutations
. Baseline serum alkaline phosphatase levels

Correct Answer & Explanation

. Histologic response to neoadjuvant chemotherapy

Explanation

For conventional high-grade osteosarcoma, the degree of tumor necrosis following neoadjuvant chemotherapy (histologic response) is the single most reliable prognostic indicator for long-term survival. A good response is typically defined as greater than 90% tumor necrosis. Patients with >90% necrosis have significantly better survival rates than poor responders.

Question 2268

Topic: 10. Pathology and Oncology

A 14-year-old boy presents with right thigh pain and swelling. Radiographs show a permeative, diaphyseal lesion with an 'onion-skin' periosteal reaction. Biopsy reveals uniform small round blue cells. Cytogenetic analysis of this tumor is most likely to demonstrate which of the following translocations?

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

Correct Answer & Explanation

. t(11;22)

Explanation

The clinical presentation, radiographic findings ('onion-skin' periostitis), and histology (small round blue cells) are diagnostic of Ewing sarcoma. Over 90% of Ewing sarcomas are characterized by the t(11;22)(q24;q12) chromosomal translocation, which results in the EWS-FLI1 fusion protein. t(X;18) is seen in synovial sarcoma, t(2;13) in alveolar rhabdomyosarcoma, and t(12;16) in myxoid liposarcoma.

Question 2269

Topic: Bone Tumors

A 19-year-old male presents with severe right thigh pain that is classically worse at night and dramatically relieved by NSAIDs. A CT scan reveals a 7 mm radiolucent nidus surrounded by dense reactive sclerosis in the femoral cortex. What is the most definitive and minimally invasive treatment modality for this condition?

. En bloc surgical resection
. Intralesional curettage and bone grafting
. Radiofrequency ablation (RFA) of the nidus
. External beam radiation therapy
. Long-term intravenous bisphosphonate therapy

Correct Answer & Explanation

. Radiofrequency ablation (RFA) of the nidus

Explanation

The clinical history of night pain relieved by NSAIDs, combined with the CT finding of a radiolucent nidus with surrounding sclerosis, is diagnostic of an osteoid osteoma. CT-guided radiofrequency ablation (RFA) is the standard of care, offering a highly successful, minimally invasive, and definitive treatment, replacing the historical need for surgical en bloc resection.

Question 2270

Topic: 10. Pathology and Oncology
A 55-year-old male presents with deep thigh pain. Radiographs reveal a permeative radiolucent lesion in the proximal femur with 'popcorn' calcifications. Core needle biopsy demonstrates a hypercellular hyaline cartilage tumor with nuclear atypia and binucleated cells, consistent with Grade II conventional chondrosarcoma. What is the most appropriate management?
. Intralesional curettage and bone grafting
. Intralesional curettage with adjuvant cryotherapy
. Wide local excision (en bloc resection) alone
. Wide local excision followed by adjuvant chemotherapy
. Neoadjuvant radiation therapy followed by wide local excision

Correct Answer & Explanation

. Wide local excision (en bloc resection) alone

Explanation

Conventional chondrosarcoma is notably resistant to both chemotherapy and radiation therapy due to its poor vascularity, slow division rate, and extracellular matrix properties. The mainstay of treatment for intermediate-grade (Grade II) and high-grade (Grade III) chondrosarcoma is wide local excision (en bloc resection) with negative margins. Intralesional curettage is only acceptable for Grade I (atypical cartilaginous tumors) in the appendicular skeleton.

Question 2271

Topic: 10. Pathology and Oncology

A 14-year-old boy presents with worsening knee pain and swelling. Radiographs demonstrate a mixed lytic and sclerotic lesion in the distal femoral metaphysis with a 'sunburst' periosteal reaction. Biopsy confirms a high-grade intramedullary osteosarcoma. Which of the following represents the standard, most appropriate treatment algorithm for this patient?

. Immediate wide surgical resection followed by adjuvant radiation therapy
. Neoadjuvant chemotherapy, wide surgical resection, and adjuvant chemotherapy
. Neoadjuvant radiation therapy, wide surgical resection, and adjuvant chemotherapy
. Isolated wide surgical resection with negative margins
. Intralesional curettage, cementation, and adjuvant chemotherapy

Correct Answer & Explanation

. Neoadjuvant chemotherapy, wide surgical resection, and adjuvant chemotherapy

Explanation

The standard of care for high-grade conventional intramedullary osteosarcoma is multi-agent neoadjuvant chemotherapy, followed by definitive surgical local control (limb-salvage wide resection or amputation), and concluding with adjuvant chemotherapy. Osteosarcoma is generally considered radioresistant, so radiation therapy is not a primary modality unless the tumor is unresectable.

Question 2272

Topic: 10. Pathology and Oncology

A 32-year-old female presents with a 3-month history of progressive left knee pain. Radiographs reveal an expansile, purely lytic lesion in the epiphysis of the proximal tibia, extending to the subchondral bone. A biopsy confirms the diagnosis of a Giant Cell Tumor (GCT) of bone. Staging workup is negative for metastases. Which of the following is the most appropriate primary surgical treatment?

. Marginal excision with a 1 cm margin
. Intralesional curettage alone
. Extended intralesional curettage with high-speed burring, local adjuvants, and defect filling
. Wide en bloc resection and endoprosthetic reconstruction
. Above-knee amputation

Correct Answer & Explanation

. Extended intralesional curettage with high-speed burring, local adjuvants, and defect filling

Explanation

Giant cell tumors of bone are locally aggressive benign tumors. The standard treatment to minimize the risk of local recurrence while preserving joint function is extended intralesional curettage (using a high-speed burr), followed by the application of local adjuvants (such as phenol, argon beam, or hydrogen peroxide) to kill remaining microscopic disease, and filling the defect with bone graft or PMMA cement.

Question 2273

Topic: 10. Pathology and Oncology

A 14-year-old boy presents with progressive knee pain and swelling. Radiographs reveal a poorly marginated, bone-forming lesion in the distal femoral metaphysis with elevation of the periosteum forming a Codman's triangle.

A biopsy confirms conventional osteosarcoma. Mutations in which of the following pairs of tumor suppressor genes are most commonly implicated in the pathogenesis of this condition?

. BRCA1 and PTEN
. RB1 and TP53
. APC and MLH1
. NF1 and NF2
. VHL and WT1

Correct Answer & Explanation

. RB1 and TP53

Explanation

Conventional osteosarcoma is highly malignant and characterized by the production of osteoid by tumor cells. The pathogenesis is strongly associated with mutations in the RB1 (retinoblastoma) and TP53 (p53) tumor suppressor genes. Patients with hereditary retinoblastoma or Li-Fraumeni syndrome (germline TP53 mutation) have a significantly increased risk of developing osteosarcoma.

Question 2274

Topic: 10. Pathology and Oncology

A 15-year-old boy presents with localized pain and swelling in his left mid-thigh, accompanied by a low-grade fever. Radiographs display a permeative, destructive diaphyseal lesion of the femur with a lamellated 'onion-skin' periosteal reaction. Histology shows sheets of uniform, small round blue cells. The most characteristic cytogenetic abnormality associated with this tumor is:

. t(11;22)(q24;q12)
. t(9;22)(q34;q11)
. t(X;18)(p11;q11)
. t(12;16)(q13;p11)
. t(2;13)(q35;q14)

Correct Answer & Explanation

. t(11;22)(q24;q12)

Explanation

The clinical presentation, radiographic findings (diaphyseal lesion, onion-skin periosteal reaction), and histology (small round blue cells) are diagnostic for Ewing sarcoma. The hallmark cytogenetic abnormality is the t(11;22)(q24;q12) chromosomal translocation, which is present in over 85% of cases and results in the formation of the EWS-FLI1 fusion transcript.

Question 2275

Topic: 10. Pathology and Oncology

An 11-year-old boy presents with a painful mass on his thigh and fever. Radiographs show a permeative diaphyseal lesion with an 'onion skin' periosteal reaction. Biopsy reveals small round blue cells.

Which chromosomal translocation is most characteristic of this tumor?

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

Correct Answer & Explanation

. t(11;22)

Explanation

Ewing sarcoma is characterized by small, round, blue cells and classically presents in the diaphysis of long bones with an 'onion skin' periosteal reaction. It is associated with the t(11;22)(q24;q12) translocation, resulting in the EWS-FLI1 fusion protein in approximately 85% of cases.

Question 2276

Topic: 10. Pathology and Oncology

A 16-year-old male presents with a painful mass near his distal femur. Radiographs show a destructive, permeative lesion with a 'sunburst' periosteal reaction. Biopsy confirms osteosarcoma.

Following standard neoadjuvant chemotherapy and wide surgical resection, which of the following is the most significant prognostic factor for long-term overall survival?

. Initial size of the primary tumor
. Anatomic location of the tumor
. Percentage of tumor necrosis in the resected specimen
. Serum alkaline phosphatase level at initial presentation
. Use of limb salvage surgery versus amputation

Correct Answer & Explanation

. Percentage of tumor necrosis in the resected specimen

Explanation

In the treatment of high-grade osteosarcoma, the histologic response of the tumor to neoadjuvant chemotherapy (measured by the percentage of tumor necrosis in the definitive surgical specimen) is widely considered the single most important prognostic factor for long-term survival. A good response is typically defined as >90% or >95% necrosis. Limb salvage versus amputation does not impact overall survival, provided negative surgical margins are obtained.

Question 2277

Topic: 10. Pathology and Oncology

A 14-year-old boy presents with a painful, swollen thigh. Radiographs reveal a permeative, diaphyseal lesion of the femur with an extensive 'onion-skin' periosteal reaction.

A core needle biopsy is performed. Which of the following chromosomal translocations and resulting fusion proteins is most characteristic of this tumor?

. t(X;18); SYT-SSX
. t(11;22); EWS-FLI1
. t(12;16); TLS-CHOP
. t(2;13); PAX3-FKHR
. t(9;22); BCR-ABL

Correct Answer & Explanation

. t(11;22); EWS-FLI1

Explanation

The clinical and radiographic presentation is classic for Ewing sarcoma. Ewing sarcoma is a small round blue cell tumor most commonly arising in the diaphysis of long bones in children and adolescents. It is defined by the t(11;22)(q24;q12) translocation in ~85% of cases, which produces the EWS-FLI1 fusion protein. SYT-SSX is associated with synovial sarcoma. TLS-CHOP is seen in myxoid liposarcoma. PAX3-FKHR is seen in alveolar rhabdomyosarcoma.

Question 2278

Topic: 10. Pathology and Oncology

A 15-year-old boy presents with progressive, severe night pain in his distal thigh over 2 months. Radiographs reveal a mixed lytic and sclerotic lesion in the distal femoral metaphysis with a robust periosteal reaction demonstrating a 'sunburst' pattern. Biopsy confirms high-grade intramedullary osteosarcoma. Which of the following genetic mutations is most frequently implicated in the pathogenesis of this tumor?

. t(11;22) translocation
. t(X;18) translocation
. Mutations in the RB1 and TP53 tumor suppressor genes
. t(9;22) translocation
. t(2;13) translocation

Correct Answer & Explanation

. Mutations in the RB1 and TP53 tumor suppressor genes

Explanation

Osteosarcoma is strongly associated with mutations in the tumor suppressor genes RB1 (retinoblastoma gene) and TP53 (Li-Fraumeni syndrome). t(11;22) is characteristic of Ewing sarcoma. t(X;18) is seen in synovial sarcoma. t(2;13) is characteristic of alveolar rhabdomyosarcoma.

Question 2279

Topic: 10. Pathology and Oncology



A 14-year-old boy presents with severe, unrelenting thigh pain and low-grade fevers. Radiographs show a permeative diaphyseal lesion with an 'onion-skin' periosteal reaction. Biopsy reveals sheets of uniform small round blue cells. Which chromosomal translocation is most characteristic of this condition?

. t(X;18)(p11;q11)
. t(11;22)(q24;q12)
. t(12;16)(q13;p11)
. t(2;13)(q35;q14)
. t(9;22)(q34;q11)

Correct Answer & Explanation

. t(11;22)(q24;q12)

Explanation

The clinical, radiographic, and histologic presentation is classic for Ewing sarcoma. The diagnostic hallmark of Ewing sarcoma is the t(11;22)(q24;q12) translocation, which results in the EWS-FLI1 fusion protein. Option A (t(X;18)) is found in synovial sarcoma. Option C (t(12;16)) is associated with myxoid liposarcoma. Option D (t(2;13)) is seen in alveolar rhabdomyosarcoma. Option E (t(9;22)) is the Philadelphia chromosome seen in CML.

Question 2280

Topic: 10. Pathology and Oncology

A 50-year-old male undergoes biopsy of a painful, enlarging proximal humerus mass, confirming the diagnosis of a conventional Grade II chondrosarcoma. Staging reveals no evidence of metastasis. What is the standard primary treatment modality for this lesion?

. Neoadjuvant chemotherapy followed by wide surgical excision
. Wide surgical excision alone
. Primary fractionated radiation therapy
. Intralesional curettage, adjuvant argon beam, and bone grafting
. Neoadjuvant radiation followed by wide excision

Correct Answer & Explanation

. Wide surgical excision alone

Explanation

Conventional intermediate and high-grade chondrosarcomas are notably resistant to both chemotherapy and radiation therapy due to their low mitotic rate, poor vascularity, and abundant extracellular matrix. Therefore, the mainstay of treatment for a Grade II chondrosarcoma is wide surgical excision with negative margins. Intralesional curettage is reserved for benign cartilage lesions (e.g., enchondromas) or very select low-grade (Grade I) chondrosarcomas in the appendicular skeleton.

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