Menu

10. Pathology and Oncology MCQs

Practice Set 302 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 6021

Topic: 10. Pathology and Oncology

A 14-year-old boy presents with mild thigh pain. Radiographs show a well-circumscribed, eccentric, lucent lesion with a sclerotic rim in the distal femoral metaphysis.

If this lesion occupies 60% of the bone diameter, what is the recommended management?

. Observation with serial radiographs
. Curettage and bone grafting
. En bloc resection
. Core needle biopsy
. Radiation therapy

Correct Answer & Explanation

. Curettage and bone grafting

Explanation

Non-ossifying fibromas (NOFs) occupying more than 50% of the bone diameter or greater than 33 mm in length are at high risk for pathologic fracture. Prophylactic curettage and bone grafting are indicated in symptomatic or high-risk lesions.

Question 6022

Topic: 10. Pathology and Oncology

A 28-year-old woman presents with progressive shoulder pain and profound regional bone resorption seen on imaging.

Biopsy demonstrates angiomatosis with thin-walled vascular channels replacing bone without cellular atypia. What is the most likely diagnosis?

. Angiosarcoma
. Gorham-Stout disease
. Paget disease of bone
. Skeletal hemangiomatosis
. Aneurysmal bone cyst

Correct Answer & Explanation

. Gorham-Stout disease

Explanation

Gorham-Stout disease, or massive osteolysis/"vanishing bone disease," is characterized by spontaneous, progressive bone resorption due to non-neoplastic proliferation of vascular and lymphatic channels. Diagnosis requires excluding malignancy or infection.

Question 6023

Topic: 10. Pathology and Oncology
A 16-year-old boy is diagnosed with high-grade conventional osteosarcoma of the distal femur. He undergoes 10 weeks of neoadjuvant chemotherapy. Which of the following is the most important prognostic factor for long-term survival in this patient?
. Size of the primary tumor
. Extent of histologic tumor necrosis at the time of surgical resection
. Specific type of neoadjuvant chemotherapy agents used
. The surgical margin distance in millimeters
. Presence of skip lesions on initial MRI

Correct Answer & Explanation

. Extent of histologic tumor necrosis at the time of surgical resection

Explanation

The most critical prognostic factor for long-term survival in osteosarcoma is the percentage of histologic tumor necrosis following neoadjuvant chemotherapy. A necrosis rate of >90% (Huvos grade III or IV) correlates with a significantly better prognosis.

Question 6024

Topic: 10. Pathology and Oncology

A 62-year-old man with known renal cell carcinoma presents with a solitary, destructive lytic lesion in the proximal humerus with impending fracture. Before proceeding with prophylactic internal fixation, what preoperative intervention is highly recommended?

. Preoperative radiation therapy
. Preoperative angioembolization
. Neoadjuvant chemotherapy
. Administration of intravenous bisphosphonates 24 hours prior
. Fine-needle aspiration biopsy

Correct Answer & Explanation

. Preoperative angioembolization

Explanation

Metastatic lesions from renal cell carcinoma and thyroid carcinoma are notoriously hypervascular. Preoperative angioembolization is strongly recommended to minimize catastrophic intraoperative blood loss during stabilization.

Question 6025

Topic: 10. Pathology and Oncology

A 55-year-old heavy alcohol user with known multifocal medullary bone infarcts in the distal femur and proximal tibia presents with a 3-month history of rapidly worsening knee pain. Recent imaging reveals a destructive, permeative soft-tissue mass arising from an area of chronic infarction in the distal femur. What is the most common malignant transformation associated with this chronic lesion?

. Chondrosarcoma
. Ewing sarcoma
. Undifferentiated pleomorphic sarcoma (UPS)
. Multiple myeloma
. Adamantinoma

Correct Answer & Explanation

. Undifferentiated pleomorphic sarcoma (UPS)

Explanation

Chronic medullary bone infarcts, which are strongly associated with heavy alcohol use and corticosteroid exposure, have a small risk of malignant transformation. The most common resulting malignancy is undifferentiated pleomorphic sarcoma (UPS, formerly known as malignant fibrous histiocytoma), followed by secondary osteosarcoma.

Question 6026

Topic: 10. Pathology and Oncology

A 25-year-old male presents with a progressive vanishing of the clavicle and ribs over several years, leading to a visible deformity and aching pain. A biopsy of the remaining clavicular bone shows extensive vascular proliferation replacing the normal bone trabeculae.

What is the most likely diagnosis?

. Gorham-Stout disease
. Paget's disease of bone
. Ewing sarcoma
. Aneurysmal bone cyst
. Fibrous dysplasia

Correct Answer & Explanation

. Gorham-Stout disease

Explanation

Gorham-Stout disease, or massive osteolysis, is a rare condition characterized by spontaneous, progressive resorption of bone associated with angiomatous or lymphangiomatous proliferation. It classically presents as "vanishing bone" on radiographs.

Question 6027

Topic: 10. Pathology and Oncology
A 15-year-old male treated with neoadjuvant chemotherapy for a distal femur osteosarcoma undergoes wide surgical resection. Pathologic evaluation of the excised tumor is performed to determine the histologic response. According to the Huvos grading system, what percentage of tumor necrosis represents a 'good' response associated with improved survival?
. Greater than 50%
. Greater than 75%
. Greater than 90%
. Exactly 100% only
. Necrosis rate does not correlate with survival in osteosarcoma

Correct Answer & Explanation

. Greater than 90%

Explanation

A 'good' histologic response to neoadjuvant chemotherapy in osteosarcoma is defined as greater than 90% tumor necrosis (Huvos grades III and IV). This degree of necrosis strongly correlates with improved long-term survival.

Question 6028

Topic: 10. Pathology and Oncology

A 60-year-old male presents with deep pelvic pain. Radiographs and subsequent MRI demonstrate a large, destructive, expansile lesion in the ilium with classic 'rings and arcs' calcifications. A core needle biopsy confirms a Grade 2 conventional chondrosarcoma. What is the standard of care for this lesion?

. Neoadjuvant multidrug chemotherapy followed by wide surgical excision.
. Intralesional curettage augmented with phenol and polymethylmethacrylate (PMMA).
. Wide surgical resection alone.
. Primary stereotactic body radiation therapy.
. Radiofrequency ablation combined with bisphosphonates.

Correct Answer & Explanation

. Wide surgical resection alone.

Explanation

Intermediate (Grade 2) and high-grade (Grade 3) conventional chondrosarcomas are relatively resistant to both chemotherapy and radiation. The definitive standard treatment is wide surgical resection with negative margins.

Question 6029

Topic: 10. Pathology and Oncology

A 14-year-old girl is found to have a permeative diaphyseal lesion in her femur with an associated 'onion skin' periosteal reaction. A biopsy is planned to confirm the suspected diagnosis of Ewing sarcoma. Which cytogenetic abnormality is most likely to be identified?

. t(11;22) translocation
. t(X;18) translocation
. t(12;16) translocation
. MDM2 gene amplification
. RUNX2 gene mutation

Correct Answer & Explanation

. t(11;22) translocation

Explanation

Ewing sarcoma is classically characterized by the t(11;22)(q24;q12) translocation, which results in the EWS-FLI1 fusion protein. In contrast, t(X;18) is pathognomonic for synovial sarcoma.

Question 6030

Topic: Bone Tumors

A 65-year-old male presents with generalized bone pain, severe fatigue, and a large radiolucent lesion in the proximal femur. Laboratory workup shows hypercalcemia, normocytic anemia, and an M-spike on serum protein electrophoresis. Which distinct radiographic characteristic of the bone lesion is classically associated with the underlying pathophysiology of this disease?

. Dense sclerotic borders surrounding the central lucency.
. 'Punched-out' lytic lesions totally lacking reactive sclerosis.
. Extensive periosteal sunburst reaction with Codman's triangle.
. A small radiolucent nidus surrounded by thick cortical thickening.
. The 'fallen leaf' sign within the medullary canal.

Correct Answer & Explanation

. 'Punched-out' lytic lesions totally lacking reactive sclerosis.

Explanation

Multiple myeloma classically presents with multiple 'punched-out' lytic lesions that lack a reactive sclerotic border. This occurs because myeloma cells secrete factors (like DKK1) that profoundly inhibit osteoblast activity while stimulating osteoclasts, preventing reactive bone formation.

Question 6031

Topic: 10. Pathology and Oncology

A 24-year-old female presents with progressive, dull aching shoulder pain over 2 years and notable deformity. Radiographs show dramatic resorption of the proximal humerus and scapula, as seen in the provided image. Biopsy reveals benign vascular proliferation with thin-walled channels replacing bone, without any malignant features.

What is the underlying pathophysiology of this condition?

. Proliferation of benign vascular and lymphatic channels causing osteoclastic resorption
. Monoclonal plasma cell proliferation stimulating osteoclast activating factor
. Recurrent microtrauma leading to neuropathic arthropathy and bone fragmentation
. Mutation in the GNAS1 gene resulting in fibrous tissue replacement of normal bone
. Aggressive local giant cell proliferation in the epiphysis extending into the metaphysis

Correct Answer & Explanation

. Proliferation of benign vascular and lymphatic channels causing osteoclastic resorption

Explanation

Gorham-Stout disease (vanishing bone disease) is characterized by massive osteolysis driven by the proliferation of benign, non-neoplastic vascular and lymphatic channels. This angiomatosis stimulates aggressive local osteoclastic bone resorption without malignant features.

Question 6032

Topic: 10. Pathology and Oncology

A 14-year-old male sustains a minor twisting injury to his ankle. Radiographs demonstrate an incidental eccentrically located, multilobulated radiolucent lesion with a sclerotic margin in the distal tibial metaphysis.

If advanced imaging confirms this lesion occupies 60% of the bone's cross-sectional diameter, what is the most appropriate management?

. Observation with serial radiographs
. Curettage and bone grafting
. Wide en bloc resection
. Intralesional injection of corticosteroids
. Core needle biopsy and systemic chemotherapy

Correct Answer & Explanation

. Curettage and bone grafting

Explanation

While small nonossifying fibromas (NOFs) are routinely observed, prophylactic curettage and bone grafting is recommended for lesions exceeding 50% of the bone diameter. This intervention minimizes the high risk of a subsequent pathologic fracture.

Question 6033

Topic: 10. Pathology and Oncology

A 26-year-old man presents with progressive swelling and pain in his ring finger metacarpophalangeal joint without a history of trauma. Imaging reveals an expansile, lytic, subchondral lesion without cystic components. Which of the following is the most likely diagnosis?

. Enchondroma
. Aneurysmal bone cyst
. Giant cell tumor
. Osteoid osteoma
. Chondroblastoma

Correct Answer & Explanation

. Giant cell tumor

Explanation

Correct Answer: CThe subchondral location and expansile, lytic nature of the lesion in a skeletally mature individual are highly characteristic of a giant cell tumor of bone. While enchondromas are the most common benign bone tumors of the hand, they are typically diaphyseal/metaphyseal and often have calcified matrix. Aneurysmal bone cysts would typically show fluid-fluid levels on MRI, which are absent here.

Question 6034

Topic: 10. Pathology and Oncology

A 40-year-old man undergoes biopsy of a slow-growing, painless soft-tissue mass around his left ankle. Histology reveals a biphasic pattern of epithelial cells and fibrous spindle cells. Immunohistochemical staining of this lesion is most likely to be positive for which of the following markers?

. S-100
. Desmin
. Keratin
. CD34
. Smooth muscle actin

Correct Answer & Explanation

. Keratin

Explanation

Correct Answer: CThe histologic description of a biphasic pattern of epithelial cells and fibrous spindle cells is classic for a synovial sarcoma. Synovial sarcomas characteristically stain positive for epithelial markers such as cytokeratin (keratin) and epithelial membrane antigen (EMA). They are also associated with the chromosomal translocation t(X;18).

Question 6035

Topic: 10. Pathology and Oncology

A 26-year-old man presents with progressive swelling and pain in his ring finger metacarpophalangeal joint without a history of trauma. Radiographs and MRI are provided. The lesion is lytic, expansile, and extends to the subchondral bone without cystic components. Which of the following is the most likely diagnosis?

. Enchondroma
. Aneurysmal bone cyst
. Giant cell tumor of bone
. Osteoid osteoma
. Chondroblastoma

Correct Answer & Explanation

. Giant cell tumor of bone

Explanation

Correct Answer: C. Giant cell tumor of boneThe subchondral location, expansile lytic nature, and lack of cystic components on MRI in a skeletally mature patient are highly characteristic of a giant cell tumor of bone. While enchondromas are the most common benign bone tumors of the hand, they typically have chondroid matrix calcifications and do not typically extend to the subchondral bone in this aggressive, expansile manner.

Question 6036

Topic: 10. Pathology and Oncology
A 40-year-old man presents with a slow-growing, painless mass around his left ankle. MRI and biopsy specimens are provided. Histology demonstrates a biphasic pattern of epithelial cells and fibrous spindle cells. Immunohistochemical staining of this tumor would most likely be positive for which of the following markers?
. S-100
. Desmin
. Keratin
. CD34
. Factor VIII

Correct Answer & Explanation

. Keratin

Explanation

The clinical presentation, location, and biphasic histologic pattern (epithelial and spindle cells) are characteristic of a synovial sarcoma. Synovial sarcomas characteristically stain positive for epithelial markers such as keratin (cytokeratin) and epithelial membrane antigen (EMA), even in the monophasic spindle cell variant.

Question 6037

Topic: 10. Pathology and Oncology

A 28-year-old woman presents with a slow-growing, painless mass around her right knee. Biopsy reveals a biphasic pattern of epithelial cells and fibrous spindle cells. Immunohistochemical staining of this lesion is most likely to be positive for which of the following markers?

. S-100
. Desmin
. Keratin
. CD34
. Smooth muscle actin

Correct Answer & Explanation

. Keratin

Explanation

Correct Answer: CThe clinical presentation and biphasic histologic pattern (epithelial cells and fibrous spindle cells) are characteristic of a synovial sarcoma. Synovial sarcomas characteristically stain positive for keratin (specifically cytokeratin) and epithelial membrane antigen (EMA). Keratin is positive in nearly all biphasic types and many monophasic fibrous types.

Question 6038

Topic: 10. Pathology and Oncology
A 25-year-old professional soccer player undergoes arthroscopic microfracture for a 1.5 cm symptomatic full-thickness articular cartilage defect on the medial femoral condyle. One year later, a biopsy of the repaired tissue would predominantly demonstrate which of the following types of collagen?
. Type I
. Type II
. Type IV
. Type IX
. Type X

Correct Answer & Explanation

. Type I

Explanation

Microfracture is a marrow stimulation technique that relies on stem cells from the underlying subchondral bone marrow to form a repair tissue. Biopsy findings in both animals and humans have demonstrated that the repair tissue is primarily fibrocartilage, not hyaline articular cartilage. Fibrocartilage is composed mostly of Type I (and Type III) collagen, whereas normal hyaline articular cartilage is predominantly Type II collagen.

Question 6039

Topic: 10. Pathology and Oncology

While most benign bone tumors remain localized, certain histologically benign lesions have a known propensity to occasionally metastasize to the lungs. Which of the following pairs of benign bone lesions is most recognized for this potential?

. Osteoid osteoma and nonossifying fibroma
. Chondroblastoma and giant cell tumor
. Aneurysmal bone cyst and fibrous dysplasia
. Chondromyxoid fibroma and enchondroma
. Unicameral bone cyst and osteochondroma

Correct Answer & Explanation

. Chondroblastoma and giant cell tumor

Explanation

Correct Answer: BAlthough considered benign bone lesions, both giant cell tumors of bone and chondroblastomas have a well-documented potential to develop "benign" lung metastases. These pulmonary implants are histologically identical to the primary benign tumor and can often be treated successfully with surgical resection (multiple thoracotomies), resulting in long-term survival.

Question 6040

Topic: 10. Pathology and Oncology

The spread of metastatic prostate carcinoma to the lumbar spine is facilitated by a valveless venous network that allows retrograde blood flow, particularly during periods of increased intra-abdominal pressure. This network extends from the sacrum to which of the following structures?

. The inferior vena cava
. The azygous vein
. The dural venous sinuses of the skull
. The portal vein
. The pulmonary venous system

Correct Answer & Explanation

. The dural venous sinuses of the skull

Explanation

Correct Answer: CIn 1940, Batson described a valveless plexus of veins that extend from the dural venous sinuses of the skull to the sacrum. This system permits retrograde blood flow and enables tumor cells to enter vertebral bodies at multiple levels. Increased intra-abdominal pressure enhances this retrograde blood flow, explaining the frequent metastasis of pelvic tumors (like prostate cancer) to the spine.

Test Yourself

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

On this Page