Menu

10. Pathology and Oncology MCQs

Practice Set 273 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 5441

Topic: 10. Pathology and Oncology

What is the typical time frame for definitive biopsy results for a complex bone sarcoma, including all special studies (IHC, molecular)?

. Within 24 hours.
. 2-3 days.
. 7-10 days.
. 3-4 weeks.
. Immediately during the procedure (frozen section).

Correct Answer & Explanation

. 7-10 days.

Explanation

For a complex bone sarcoma, a definitive diagnosis, including routine histology, immunohistochemistry (IHC), and any necessary molecular studies (e.g., FISH, RT-PCR), typically takes 7-10 days, and sometimes longer if tissue decalcification is extensive or if multiple specialized tests are required. While frozen sections provide immediate feedback on tissue adequacy, they are not definitive. 24-hour or 2-3 day turnarounds are generally for simpler cases or preliminary reads, not comprehensive diagnoses of sarcomas.

Question 5442

Topic: 10. Pathology and Oncology

When discussing the potential complications of a biopsy with a patient, which of the following should always be highlighted, especially for suspected malignant lesions?

. Temporary numbness around the biopsy site.
. Mild post-operative pain requiring over-the-counter medication.
. The possibility of a non-diagnostic biopsy requiring a repeat procedure.
. Bruising and swelling that resolves within a few days.
. A slight scar at the incision site.

Correct Answer & Explanation

. The possibility of a non-diagnostic biopsy requiring a repeat procedure.

Explanation

One of the most important potential complications to discuss with a patient undergoing biopsy for a suspected malignant lesion is the possibility of a non-diagnostic biopsy, which would necessitate a repeat procedure. This manages patient expectations and prepares them for the possibility of further intervention, which can be frustrating but is sometimes unavoidable due to tumor heterogeneity or sampling limitations. While other options are also potential complications, the need for a repeat biopsy is a significant outcome that directly impacts the diagnostic pathway.

Question 5443

Topic: 10. Pathology and Oncology

A patient presents with a suspicious lesion in the proximal humerus. Pre-biopsy imaging shows extensive bone destruction and a large soft tissue component. Which type of biopsy is generally preferred to maximize diagnostic yield while minimizing risk?

. Open incisional biopsy
. CT-guided core needle biopsy
. Fine needle aspiration (FNA)
. Excisional biopsy
. Blind biopsy based on physical exam

Correct Answer & Explanation

. CT-guided core needle biopsy

Explanation

For a suspicious lesion with extensive bone destruction and a large soft tissue component, a CT-guided core needle biopsy is generally preferred. It offers excellent targeting accuracy, can sample both bone and soft tissue components, and provides sufficient tissue for full histological and molecular analysis. Open incisional biopsy carries a higher risk of tumor seeding. FNA may be insufficient. Excisional biopsy is not appropriate for large, destructive lesions. Blind biopsy is unacceptable for deep, complex lesions.

Question 5444

Topic: 10. Pathology and Oncology

What is the primary oncologic rationale for performing a biopsy prior to initiating neoadjuvant chemotherapy for a suspected high-grade sarcoma?

. To allow the patient to recover from biopsy before chemotherapy.
. To confirm the diagnosis and tumor type, which dictates the specific chemotherapy regimen.
. To assess the tumor's response to initial chemotherapy.
. To reduce the tumor size, making the biopsy easier.
. To identify any genetic mutations that might preclude chemotherapy.

Correct Answer & Explanation

. To confirm the diagnosis and tumor type, which dictates the specific chemotherapy regimen.

Explanation

The primary oncologic rationale for performing a biopsy prior to neoadjuvant chemotherapy for a suspected high-grade sarcoma is to definitively confirm the diagnosis and identify the specific tumor type and grade. The exact chemotherapy regimen (e.g., for osteosarcoma vs. Ewing sarcoma vs. rhabdomyosarcoma) is highly dependent on the precise histological diagnosis. Initiating chemotherapy without a confirmed diagnosis is inappropriate and potentially harmful.

Question 5445

Topic: 10. Pathology and Oncology

During a bone biopsy, the use of a power drill to obtain cores can lead to which specific artifact that might complicate pathological interpretation?

. Thermal artifact causing cell necrosis.
. Crush artifact distorting cell morphology.
. Inadequate tissue sample.
. Contamination with normal bone marrow.
. Loss of cellular detail due to decalcification.

Correct Answer & Explanation

. Thermal artifact causing cell necrosis.

Explanation

The heat generated by a power drill or powered bone trephine can cause thermal artifact, leading to coagulation necrosis of cells at the margins of the biopsy specimen. This can obscure diagnostic features and make pathological interpretation more challenging. While crush artifact can occur with any forceful biopsy, thermal artifact is specific to powered instruments. Inadequate sampling, contamination, and decalcification issues are not specific to power drills.

Question 5446

Topic: 10. Pathology and Oncology

A core needle biopsy is performed for a suspected low-grade chondrosarcoma. If the biopsy is non-diagnostic, what is the major risk of prolonged observation instead of further diagnostic pursuit?

. Increased risk of infection.
. Rapid progression to high-grade sarcoma.
. Increased difficulty for definitive surgical resection due to tumor growth.
. Patient developing pathological fracture.
. Loss of limb-salvage potential.

Correct Answer & Explanation

. Loss of limb-salvage potential.

Explanation

For a suspected low-grade chondrosarcoma with a non-diagnostic biopsy, prolonged observation carries the major risk of tumor growth, potentially leading to increased difficulty for definitive surgical resection and, critically, a loss of limb-salvage potential. While low-grade chondrosarcomas are slow-growing, delayed diagnosis and treatment allow the tumor to expand, potentially involving more critical structures, making wide resection with limb salvage more challenging or impossible. They rarely rapidly progress to high grade spontaneously.

Question 5447

Topic: 10. Pathology and Oncology

Which factor is LEAST likely to affect the diagnostic yield of a bone biopsy?

. Size of the biopsy needle.
. Experience of the biopsy operator.
. Presence of extensive tumor necrosis.
. Pre-biopsy administration of analgesics.
. Image guidance for needle placement.

Correct Answer & Explanation

. Pre-biopsy administration of analgesics.

Explanation

Pre-biopsy administration of analgesics primarily addresses patient comfort and pain management. It has virtually no direct impact on the diagnostic yield of the biopsy specimen itself. In contrast, the size of the needle, operator experience, presence of necrosis, and use of image guidance are all significant factors that directly influence whether an adequate and representative tissue sample is obtained for diagnosis.

Question 5448

Topic: 10. Pathology and Oncology

In a patient with suspected chordoma of the sacrum, what specific pathological finding on biopsy is essential for definitive diagnosis?

. Multinucleated giant cells.
. Spindle cells with high mitotic activity.
. Physaliferous cells in a myxoid matrix.
. Small round blue cells with rosette formation.
. Woven bone and osteoid production.

Correct Answer & Explanation

. Physaliferous cells in a myxoid matrix.

Explanation

Chordomas are characterized by the presence of physaliferous cells, which are vacuolated cells, often arranged in cords or nests within a myxoid matrix. These are derived from notochordal remnants and are pathognomonic for chordoma. Other options describe features of other bone tumors: giant cells for GCT, spindle cells for various sarcomas, small round blue cells for Ewing, and woven bone for osteosarcoma.

Question 5449

Topic: 10. Pathology and Oncology

A patient undergoes a biopsy for a suspected aggressive lesion in the proximal femur. Post-biopsy, the patient develops a pathological fracture. What is the MOST appropriate immediate management?

. Immediately initiate chemotherapy.
. Apply traction and observe for healing.
. Perform open reduction and internal fixation to stabilize the fracture, concurrently taking further biopsy samples if needed.
. Proceed directly to amputation.
. Prescribe strict bed rest and analgesics.

Correct Answer & Explanation

. Perform open reduction and internal fixation to stabilize the fracture, concurrently taking further biopsy samples if needed.

Explanation

If a pathological fracture occurs after a biopsy of a suspected aggressive lesion, the most appropriate immediate management is to stabilize the fracture, typically with open reduction and internal fixation. This provides pain relief, allows for patient mobility, and protects the limb. During this procedure, additional, larger, and well-targeted biopsy samples can be taken to ensure a definitive diagnosis. Chemotherapy is not initiated without a confirmed diagnosis. Amputation is a last resort, and observation/bed rest are usually insufficient for unstable pathological fractures.

Question 5450

Topic: 10. Pathology and Oncology

A 30-year-old female presents with progressive spastic paraparesis, gait disturbance, and dissociated sensory loss (loss of pain and temperature sensation with preserved touch and proprioception) in her upper extremities. MRI of the cervical spine reveals an enhancing intramedullary lesion extending from C3 to C6 with a large associated syrinx. The most likely diagnosis is:

. Spinal Meningioma
. Cervical Schwannoma
. Spinal Cord Astrocytoma
. Ependymoma
. Transverse Myelitis

Correct Answer & Explanation

. Ependymoma

Explanation

The clinical picture of progressive spastic paraparesis, gait disturbance, and dissociated sensory loss (syringomyelic pattern) in the context of an enhancing intramedullary lesion with a large syrinx is classic for an ependymoma. While astrocytomas can also be intramedullary and cause similar symptoms, ependymomas are more commonly associated with prominent syrinx formation and are the most common intramedullary tumor in adults. Meningiomas and schwannomas are intradural-extramedullary. Transverse myelitis is an inflammatory condition and typically has a more acute onset, though imaging might show enhancement.

Question 5451

Topic: 10. Pathology and Oncology

A 10-year-old child presents with an expansile, lytic lesion involving the vertebral body and posterior elements of L3, with associated paraspinal soft tissue mass. Biopsy reveals small round blue cells with prominent vascular channels. Immunohistochemistry is positive for CD99 and EWSR1 rearrangement. What is the most likely diagnosis?

. Osteosarcoma
. Chondrosarcoma
. Ewing's Sarcoma
. Rhabdomyosarcoma
. Neuroblastoma

Correct Answer & Explanation

. Ewing's Sarcoma

Explanation

The clinical presentation in a child (age 10), the location (vertebral body and posterior elements), the lytic-expansile nature with soft tissue mass, and especially the histological findings of small round blue cells with CD99 positivity and EWSR1 gene rearrangement are pathognomonic for Ewing's Sarcoma. Osteosarcoma and chondrosarcoma have different histological features. Rhabdomyosarcoma is a soft tissue sarcoma. Neuroblastoma can present similarly but has different immunohistochemical markers (e.g., positive for N-myc, negative for CD99) and is more common in younger children.

Question 5452

Topic: 10. Pathology and Oncology

A patient undergoes surgical resection of a sacral chordoma. What is the most critical surgical principle to minimize local recurrence rates?

. Extensive laminectomy for decompression
. Aggressive curettage of tumor bed
. Achieving wide surgical margins (en bloc resection)
. Adjuvant conventional radiation therapy
. Intraoperative chemotherapy infusion

Correct Answer & Explanation

. Achieving wide surgical margins (en bloc resection)

Explanation

For chordomas, local recurrence is the most significant challenge. The single most important factor in preventing local recurrence is achieving wide surgical margins through an en bloc resection, removing the tumor in one piece surrounded by healthy tissue. Intralesional resection (curettage) or marginal resection significantly increases recurrence risk. While adjuvant radiation (especially proton therapy) is often used, it is secondary to the quality of the initial surgical resection. Laminectomy is for decompression, not tumor eradication. Chemotherapy has limited efficacy for chordomas.

Question 5453

Topic: 10. Pathology and Oncology

Which of the following tumors is most commonly found at the conus medullaris or filum terminale and often presents with symptoms of cauda equina syndrome?

. Cervical Astrocytoma
. Thoracic Meningioma
. Lumbar Schwannoma
. Filum Terminale Ependymoma
. Sacral Chordoma

Correct Answer & Explanation

. Filum Terminale Ependymoma

Explanation

Ependymomas, particularly the myxopapillary subtype, have a strong predilection for the conus medullaris and filum terminale. They typically present with symptoms of cauda equina syndrome, including low back pain, radicular pain, saddle anesthesia, and bowel/bladder dysfunction, due to compression of the nerve roots. Cervical astrocytomas are intramedullary but higher up. Thoracic meningiomas are intradural-extramedullary but at a different level. Lumbar schwannomas can cause cauda equina symptoms but are less specific to the filum terminale. Sacral chordomas are bone tumors and extradural.

Question 5454

Topic: 10. Pathology and Oncology

The presence of a 'dural tail sign' on contrast-enhanced MRI is highly suggestive of which intradural-extramedullary spinal tumor?

. Spinal Schwannoma
. Spinal Ependymoma
. Spinal Meningioma
. Spinal Astrocytoma
. Spinal Hemangioblastoma

Correct Answer & Explanation

. Spinal Meningioma

Explanation

The 'dural tail sign' refers to linear enhancement of the dura mater extending away from an intradural mass. While not pathognomonic, it is highly characteristic of spinal meningiomas, reflecting hypervascularity or tumor infiltration of the dura. Schwannomas can also be intradural-extramedullary but rarely present with a dural tail. Ependymomas and astrocytomas are intramedullary. Hemangioblastomas are typically intramedullary or cerebellar.

Question 5455

Topic: 10. Pathology and Oncology

What is the primary role of high-dose corticosteroids in the initial management of acute spinal cord compression due to metastatic disease?

. To directly shrink the tumor size
. To improve motor function via direct nerve regeneration
. To reduce peritumoral edema, thereby alleviating compression
. To act as a primary chemotherapeutic agent
. To prevent infection post-surgery

Correct Answer & Explanation

. To reduce peritumoral edema, thereby alleviating compression

Explanation

High-dose corticosteroids, such as Dexamethasone, are given for acute spinal cord compression primarily to reduce the inflammatory response and vasogenic edema surrounding the metastatic tumor. This reduction in edema can temporarily relieve pressure on the spinal cord, potentially preserving neurological function while definitive treatment (surgery or radiation) is planned. They do not directly shrink the tumor, regenerate nerves, or act as primary chemotherapy.

Question 5456

Topic: 10. Pathology and Oncology

Which of the following primary spinal tumors is most radiosensitive?

. Chordoma
. Chondrosarcoma
. Osteosarcoma
. Ewing's Sarcoma
. Giant Cell Tumor of Bone

Correct Answer & Explanation

. Ewing's Sarcoma

Explanation

Ewing's Sarcoma is known to be highly radiosensitive, and radiation therapy often plays a significant role in its treatment, either as definitive therapy or as an adjuvant to surgery. Chordomas and chondrosarcomas are generally considered radioresistant or require very high doses (e.g., proton therapy) for local control. Osteosarcoma and Giant Cell Tumor of Bone are also generally considered radioresistant in comparison to Ewing's.

Question 5457

Topic: 10. Pathology and Oncology

In a patient with a known history of breast cancer presenting with spinal metastasis and impending pathological fracture, what factor is most critical in determining the need for surgical intervention over non-operative management?

. Patient's age
. Size of the primary breast tumor
. Extent of cortical destruction and spinal instability
. Chemotherapy regimen currently being used
. Duration of symptoms

Correct Answer & Explanation

. Extent of cortical destruction and spinal instability

Explanation

The extent of cortical destruction, particularly involvement of the posterior column or pedicles, and the overall spinal instability are the most critical factors guiding surgical decision-making for metastatic spinal disease. Impending or actual pathological fractures, combined with instability, significantly increase the risk of neurological compromise and pain, thus warranting surgical stabilization. While other factors might influence overall management, instability is the primary driver for surgical intervention in this scenario.

Question 5458

Topic: Soft Tissue Tumors & Metastasis

A 25-year-old male presents with recurrent acute attacks of severe back and leg pain, followed by periods of remission. MRI reveals multiple well-circumscribed, enhancing intradural-extramedullary lesions in the lumbar spine, some with a cystic component. These lesions are T1 isointense and T2 hyperintense. What is the most likely diagnosis?

. Multiple Meningiomas
. Multiple Schwannomas
. Spinal Neurofibromatosis Type 1
. Spinal Hemangioblastomatosis
. Disseminated Ependymomatosis

Correct Answer & Explanation

. Multiple Schwannomas

Explanation

Multiple schwannomas (schwannomatosis) can present with recurrent attacks of pain and are typically intradural-extramedullary, well-circumscribed, and enhancing. The cystic component is also common in schwannomas. While neurofibromatosis can involve multiple nerve sheath tumors, schwannomatosis specifically refers to multiple schwannomas without evidence of NF2. Multiple meningiomas are rare in young adults without NF2. Hemangioblastomas are often intramedullary and associated with VHL disease. Disseminated ependymomatosis is rare and would typically be intramedullary in origin or CSF spread from a primary ependymoma.

Question 5459

Topic: Bone Tumors

What is the typical imaging appearance of an osteoid osteoma in the spine on CT?

. Purely lytic lesion with soft tissue mass
. Expansile 'soap bubble' appearance
. Central lucent nidus surrounded by dense reactive sclerosis
. Homogeneous blastic lesion
. T1 hyperintense, T2 hyperintense lesion

Correct Answer & Explanation

. Central lucent nidus surrounded by dense reactive sclerosis

Explanation

Osteoid osteomas are benign bone-forming tumors characterized by a small, radiolucent nidus (typically < 1.5 cm) surrounded by a zone of dense reactive sclerosis. This appearance is best seen on CT. The nidus is the metabolically active part and often shows intense uptake on bone scan. The other options describe different types of lesions: Ewing's/metastasis (lytic with soft tissue), aneurysmal bone cyst ('soap bubble'), blastic metastasis (homogeneous blastic), and hemangioma (T1/T2 hyperintense).

Question 5460

Topic: 10. Pathology and Oncology

A patient with a vertebral body collapse due to metastatic disease undergoes posterior instrumentation for stabilization. Which of the following is considered a relative contraindication for surgery in this context?

. Severe intractable pain
. Rapidly progressive neurological deficit
. Extremely short life expectancy (e.g., < 3 months)
. Single-level disease with good performance status
. Radiosensitive tumor type

Correct Answer & Explanation

. Extremely short life expectancy (e.g., < 3 months)

Explanation

Surgical intervention for metastatic spinal disease, especially complex stabilization, carries significant risks and morbidity. An extremely short life expectancy (e.g., less than 3 months) is often considered a relative contraindication, as the potential benefits of surgery may not outweigh the risks and recovery time. In such cases, palliative measures, including radiation and pain management, may be more appropriate. Severe pain, neurological deficits, and single-level disease are generally indications for considering surgery, not contraindications. Radiosensitive tumors might favor radiation but don't preclude surgery if stability is paramount.

Test Yourself

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

On this Page