Menu

10. Pathology and Oncology MCQs

Practice Set 270 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 5381

Topic: 10. Pathology and Oncology

When performing curettage for a Non-Ossifying Fibroma, what is the recommended extent of resection?

. Wide en bloc resection including a margin of normal bone.
. Intralesional curettage, removing only the soft, fibrous tissue.
. Marginal excision of the lesion with a thin rim of normal bone.
. Amputation of the affected limb.
. Partial excision leaving a portion of the lesion to prevent weakening.

Correct Answer & Explanation

. Intralesional curettage, removing only the soft, fibrous tissue.

Explanation

For benign lesions like NOF, intralesional curettage (removing the lesion from within its pseudocapsule) is the standard surgical approach. Complete removal of the fibrous tissue is the goal. Wide en bloc resection is reserved for malignant tumors or very aggressive benign lesions. Marginal excision is typically not necessary for NOF. Amputation is inappropriate. Partial excision risks leaving symptomatic tissue.

Question 5382

Topic: 10. Pathology and Oncology

What is the typical appearance of the lesion on a bone scan (technetium-99m) for an uncomplicated, asymptomatic Non-Ossifying Fibroma?

. Marked hot spot (increased uptake).
. Cold spot (decreased uptake).
. Normal uptake, similar to surrounding bone.
. Variable, often mild or no increased uptake.
. Diffuse uptake throughout the entire bone.

Correct Answer & Explanation

. Variable, often mild or no increased uptake.

Explanation

An uncomplicated, asymptomatic NOF typically shows mild or no increased uptake on bone scan, reflecting its benign, non-aggressive nature and lack of significant osteoblastic activity. A 'hot spot' would suggest a more active lesion, inflammation, or tumor. A 'cold spot' is rare for a primary bone lesion unless it's necrotic or truly avascular. Diffuse uptake is also not characteristic.

Question 5383

Topic: 10. Pathology and Oncology
A 12-year-old girl with a biopsy-proven non-ossifying fibroma of the distal tibia (40% cortical involvement, asymptomatic) and multiple similar lesions throughout the skeleton presents with café-au-lait spots. Which syndrome should be considered?
. Gardner Syndrome
. Peutz-Jeghers Syndrome
. Maffucci Syndrome
. Jaffe-Campanacci Syndrome
. Multiple Hereditary Exostoses

Correct Answer & Explanation

. Jaffe-Campanacci Syndrome

Explanation

The constellation of multiple non-ossifying fibromas and café-au-lait spots is highly suggestive of Jaffe-Campanacci Syndrome. Gardner syndrome involves osteomas, colon polyps, and soft tissue tumors. Peutz-Jeghers involves gastrointestinal polyps and mucocutaneous pigmentation. Maffucci Syndrome has enchondromas and hemangiomas. Multiple Hereditary Exostoses involves osteochondromas.

Question 5384

Topic: 10. Pathology and Oncology

A 6-year-old presents with a painless, palpable lump on the anterior aspect of the distal tibia. Radiographs show a well-defined cortical lucency with a sclerotic rim. Which statement regarding its biological behavior is most accurate?

. It will grow indefinitely and may require repeat resections.
. It is aggressive and may metastasize to distant sites.
. It is a slow-growing lesion that will often regress spontaneously.
. It rapidly invades surrounding soft tissues.
. It is typically associated with significant pain and functional impairment.

Correct Answer & Explanation

. It is a slow-growing lesion that will often regress spontaneously.

Explanation

Non-ossifying fibromas are benign, slow-growing lesions that commonly regress spontaneously. They do not metastasize, invade soft tissues aggressively, or typically cause significant pain unless large or fractured. The palpable lump is often due to cortical expansion rather than soft tissue invasion.

Question 5385

Topic: 10. Pathology and Oncology

What is the typical management for a 2 cm asymptomatic Non-Ossifying Fibroma incidentally found in the distal tibia of a 7-year-old?

. Immediate biopsy and surgical excision.
. Prophylactic internal fixation.
. Regular clinical and radiographic follow-up.
. Course of oral antibiotics.
. Referral for radiation therapy.

Correct Answer & Explanation

. Regular clinical and radiographic follow-up.

Explanation

For small, asymptomatic NOFs (like a 2 cm lesion) with classic radiographic features, the standard management is regular clinical and radiographic follow-up. These lesions often regress spontaneously. Surgical intervention, biopsy, antibiotics, or radiation therapy are not indicated for such cases.

Question 5386

Topic: 10. Pathology and Oncology

In the context of surgical intervention for NOF, when is internal fixation typically combined with curettage and bone grafting?

. For all lesions, regardless of size or location.
. Only for lesions in the upper extremity to prevent elbow stiffness.
. When there is an actual or impending pathological fracture, especially in weight-bearing bones.
. To prevent malignant transformation.
. If the patient is under 5 years old.

Correct Answer & Explanation

. When there is an actual or impending pathological fracture, especially in weight-bearing bones.

Explanation

Internal fixation (e.g., plating, rodding) is combined with curettage and bone grafting primarily when there is an actual pathological fracture or a significant risk of impending fracture (e.g., very large lesion, >50% cortical involvement) in a weight-bearing bone. This provides immediate stability and protects the bone graft. It is not indicated for all lesions, not specific to the upper extremity, and not related to malignant transformation or age per se.

Question 5387

Topic: 10. Pathology and Oncology

Why is biopsy often avoided for typical Non-Ossifying Fibromas?

. Biopsy causes rapid spread of the lesion.
. The characteristic radiographic appearance is usually diagnostic in the appropriate clinical setting.
. Biopsy is technically too difficult due to the hard sclerotic rim.
. The lesion spontaneously resolves before biopsy results are available.
. Biopsy can induce malignant transformation.

Correct Answer & Explanation

. The characteristic radiographic appearance is usually diagnostic in the appropriate clinical setting.

Explanation

For Non-Ossifying Fibromas with classic radiographic features (eccentric, lytic, sclerotic rim, metaphyseal in a child/adolescent) and an asymptomatic or mildly symptomatic presentation, a biopsy is often not necessary. The radiographic appearance is usually sufficiently diagnostic, allowing for observation or direct surgical management if indicated, avoiding the risks and costs of a biopsy. Biopsy does not cause spread or malignant transformation, and technical difficulty is not the primary reason.

Question 5388

Topic: 10. Pathology and Oncology

Which of the following describes the most common long-term outcome for a Non-Ossifying Fibroma managed conservatively?

. Persistent growth and pain requiring surgery in adulthood.
. Gradual decrease in size, increased sclerosis, and eventual complete resolution.
. Progression to malignant fibrous histiocytoma.
. Development of widespread metastatic lesions.
. Chronic intractable pain leading to disability.

Correct Answer & Explanation

. Gradual decrease in size, increased sclerosis, and eventual complete resolution.

Explanation

The most common long-term outcome for NOFs managed conservatively is gradual regression, increased sclerosis (healing), and eventual complete resolution, often leaving behind a small area of cortical thickening or sclerosis. They typically do not persist, become malignant, metastasize, or cause chronic intractable pain.

Question 5389

Topic: 10. Pathology and Oncology

Which of the following laboratory findings are typically associated with an uncomplicated Non-Ossifying Fibroma?

. Elevated alkaline phosphatase.
. Elevated erythrocyte sedimentation rate (ESR).
. Leukocytosis.
. Normal serum calcium and phosphate levels.
. Elevated parathyroid hormone.

Correct Answer & Explanation

. Normal serum calcium and phosphate levels.

Explanation

Uncomplicated Non-Ossifying Fibromas are benign fibrous lesions and do not cause systemic metabolic derangements. Therefore, laboratory values such as alkaline phosphatase, ESR, leukocyte count, serum calcium, and phosphate levels are typically normal. Elevated alkaline phosphatase can be seen in osteoblastic activity or healing fractures, but not directly from NOF itself. Elevated ESR and leukocytosis suggest infection or inflammatory processes. Elevated parathyroid hormone suggests hyperparathyroidism.

Question 5390

Topic: 10. Pathology and Oncology

When evaluating a suspected NOF in a young child, what is a key feature to differentiate it from a metaphyseal fibrous defect (MFD)?

. NOFs are always symptomatic, MFDs are not.
. MFDs are found in adults, NOFs in children.
. NOFs are larger (>2-3 cm) and often extend into the medullary cavity, while MFDs are smaller and purely cortical.
. MFDs have an aggressive appearance on radiographs, NOFs are benign.
. NOFs commonly recur after curettage, MFDs do not.

Correct Answer & Explanation

. NOFs are larger (>2-3 cm) and often extend into the medullary cavity, while MFDs are smaller and purely cortical.

Explanation

Metaphyseal fibrous defect (MFD) is synonymous with fibrous cortical defect (FCD), representing the smaller, purely cortical counterpart of a Non-Ossifying Fibroma (NOF). NOFs are generally larger, extending into the medullary canal. Both are benign, asymptomatic (unless fractured), found in children, and rarely recur. Their radiographic appearances are similar in nature, differing mainly in size and extent.

Question 5391

Topic: Bone Tumors

A 9-year-old patient presents with chronic, dull pain in the knee, worse at night and relieved by NSAIDs. Radiographs show a small (1.5 cm) lucent lesion with a central nidus and surrounding sclerotic bone in the proximal tibia. While considering the differential, why is a NOF less likely than Osteoid Osteoma in this specific clinical presentation?

. NOFs are typically purely lytic, lacking a central nidus.
. NOFs are never painful.
. NOFs are typically larger than 1.5 cm.
. Pain from NOF is not relieved by NSAIDs.
. NOFs commonly cause night pain.

Correct Answer & Explanation

. NOFs are typically purely lytic, lacking a central nidus.

Explanation

The classic presentation of an Osteoid Osteoma includes chronic pain, often worse at night, and characteristic relief with NSAIDs, along with a small lucent nidus and reactive sclerosis. While NOFs can cause pain, especially if large or fractured, they rarely present with night pain specifically relieved by NSAIDs, and their radiographic appearance is a purely lytic lesion with a sclerotic rim, not a distinct central nidus. NOFs can be small (fibrous cortical defect) or large.

Question 5392

Topic: 10. Pathology and Oncology

What surgical technique is generally preferred for the treatment of symptomatic Non-Ossifying Fibroma to minimize recurrence?

. Marginal en bloc excision.
. Intralesional curettage.
. Cryoablation.
. Radiofrequency ablation.
. Amputation.

Correct Answer & Explanation

. Intralesional curettage.

Explanation

Intralesional curettage is the standard and generally preferred surgical technique for symptomatic NOFs. The goal is to remove the fibrous tissue from within the bone. While cryoablation and radiofrequency ablation are used for some benign bone tumors, curettage is most common for NOF. Recurrence rates for NOF after thorough curettage are very low. Marginal en bloc excision or amputation are overly aggressive for this benign lesion.

Question 5393

Topic: Bone Tumors

Which radiological sign, if present, would strongly suggest a diagnosis other than Non-Ossifying Fibroma in a metaphyseal lesion?

. Eccentric cortical location.
. Sclerotic rim.
. Fluid-fluid levels on MRI.
. Multiloculated appearance.
. Cortical thinning.

Correct Answer & Explanation

. Fluid-fluid levels on MRI.

Explanation

Fluid-fluid levels on MRI are highly characteristic of an Aneurysmal Bone Cyst (ABC) and are typically not seen in a Non-Ossifying Fibroma. While NOFs can be eccentric, have a sclerotic rim, appear multiloculated, and cause cortical thinning, the presence of fluid-fluid levels would strongly point away from an NOF and towards an ABC or other cystic/hemorrhagic lesion.

Question 5394

Topic: 10. Pathology and Oncology

The cellular components of Non-Ossifying Fibroma are considered benign. What does this imply regarding their growth pattern?

. They exhibit rapid, uncontrolled proliferation and invasion.
. They have the capacity to form distant metastases.
. They grow slowly and are typically confined within a pseudocapsule.
. They undergo malignant transformation in all cases.
. They are composed of highly anaplastic cells.

Correct Answer & Explanation

. They grow slowly and are typically confined within a pseudocapsule.

Explanation

Benign lesions, including NOFs, are characterized by slow growth and usually remain confined within their site of origin, often surrounded by a reactive pseudocapsule or sclerotic rim. They do not exhibit rapid, uncontrolled proliferation, do not metastasize, do not undergo malignant transformation, and are not composed of anaplastic cells.

Question 5395

Topic: 10. Pathology and Oncology

A 10-year-old male with a large NOF in his proximal tibia asks if he will need his leg amputated. What is the most appropriate response?

. Yes, for a lesion of this size, amputation is the standard treatment.
. No, amputation is almost never required for a benign lesion like this.
. Maybe, it depends on whether it transforms into a malignant tumor.
. Only if you continue to participate in contact sports.
. Only if it affects the growth plate significantly.

Correct Answer & Explanation

. No, amputation is almost never required for a benign lesion like this.

Explanation

Amputation is almost never required for a benign lesion like a Non-Ossifying Fibroma. Even large, symptomatic, or fractured NOFs are managed with limb-sparing procedures such as curettage and bone grafting. Malignant transformation is exceedingly rare. While growth plate involvement can be a concern for limb length discrepancy, it does not typically lead to amputation. Activity modification is for fracture prevention, not amputation.

Question 5396

Topic: Bone Tumors

Which imaging finding is characteristic of a healing or 'burnt-out' Non-Ossifying Fibroma?

. Persistent large lytic lesion with no change.
. Increasingly dense, homogenous sclerosis filling the defect.
. Development of new fluid-fluid levels.
. Cortical erosion and periosteal reaction.
. Expansion into the joint space.

Correct Answer & Explanation

. Increasingly dense, homogenous sclerosis filling the defect.

Explanation

A healing or 'burnt-out' NOF is characterized by increasing central sclerosis as the fibrous tissue is replaced by normal bone, eventually leaving a dense, homogenous sclerotic area. The lesion effectively resolves and fills in. Persistent lucency, new fluid levels, cortical erosion with periosteal reaction, or joint space invasion are not typical for a healing NOF.

Question 5397

Topic: 10. Pathology and Oncology

In the differential diagnosis of a metaphyseal lesion, why is Fibrous Dysplasia a consideration for a Non-Ossifying Fibroma?

. Both lesions are always symptomatic and cause pathological fractures.
. Both lesions often show a 'ground-glass' matrix on radiographs.
. Both are benign fibrous lesions that can be metaphyseal and expansile.
. Both commonly transform into osteosarcoma.
. Both are characterized by osteoclastic predominance.

Correct Answer & Explanation

. Both are benign fibrous lesions that can be metaphyseal and expansile.

Explanation

Both Non-Ossifying Fibroma and Fibrous Dysplasia are benign fibrous lesions that commonly affect the metaphysis/diaphysis of long bones in children/adolescents and can be expansile. However, Fibrous Dysplasia typically has a 'ground-glass' matrix on radiographs and histologically shows immature woven bone in a fibrous stroma, differentiating it from NOF's characteristic sclerotic rim and storiform fibrous tissue. Neither commonly transforms into osteosarcoma, and neither is purely osteoclastic.

Question 5398

Topic: 10. Pathology and Oncology

What is the most common reason for surgical intervention in a patient with a Non-Ossifying Fibroma?

. To obtain a definitive diagnosis via biopsy for all lesions.
. To prevent malignant transformation.
. Significant pain, pathological fracture, or risk of impending fracture.
. Cosmetic reasons due to skin discoloration.
. To prevent growth plate arrest in all cases.

Correct Answer & Explanation

. Significant pain, pathological fracture, or risk of impending fracture.

Explanation

The most common indications for surgical intervention (curettage and bone grafting) in NOF are significant pain, an actual pathological fracture, or a high risk of impending fracture (e.g., large lesion >50% cortical involvement). Biopsy is often not needed for classic cases. Malignant transformation is virtually non-existent. Cosmetic reasons are not typically an indication. Growth plate arrest is not a common complication that always requires surgery for NOF unless it's very close or involved in a fracture.

Question 5399

Topic: Bone Tumors
A 10-year-old is incidentally found to have a small, <1 cm, purely cortical fibrous lesion in the distal femur. What is the most appropriate descriptive term for this lesion?
. Non-Ossifying Fibroma
. Fibrous Cortical Defect
. Osteofibrous Dysplasia
. Unicameral Bone Cyst
. Cortical Desmoid

Correct Answer & Explanation

. Fibrous Cortical Defect

Explanation

A small (<2-3 cm), purely cortical fibrous lesion in the metaphysis is most accurately termed a Fibrous Cortical Defect (FCD). Non-Ossifying Fibroma (NOF) is typically used for larger lesions that extend into the medullary cavity, though they are considered the same entity pathologically. Osteofibrous dysplasia is a distinct entity often in the tibia/fibula with epithelial rests. UBC is medullary and cystic. Cortical desmoid is a normal variant (stress phenomenon) at the posterior medial femoral condyle, often bilateral.

Question 5400

Topic: 10. Pathology and Oncology

Which of the following describes the prognosis for a Non-Ossifying Fibroma after successful surgical treatment?

. High rate of local recurrence and persistent pain.
. Excellent, with rare recurrence and resolution of symptoms.
. Frequent malignant transformation requiring lifelong surveillance.
. Progressive bone destruction and deformity.
. Recurrence rates similar to giant cell tumor.

Correct Answer & Explanation

. Excellent, with rare recurrence and resolution of symptoms.

Explanation

The prognosis after successful surgical treatment (curettage) of a Non-Ossifying Fibroma is excellent. Recurrence is rare (less than 5-10% in most series) and typically resolves symptoms. Unlike more aggressive benign lesions such as giant cell tumor, NOF has very low recurrence potential. Malignant transformation is not a concern, nor is progressive bone destruction.

Test Yourself

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

On this Page