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 3481
Topic: 10. Pathology and Oncology
A 16-year-old male complains of dull, aching pain in his vastus medialis that worsens after exercise. Radiographs reveal multiple small, smooth, rounded radiopacities with radiolucent centers. MRI shows a lobulated mass with high signal on T2-weighted images and a "bag of worms" appearance. What is the most appropriate initial management?
Correct Answer & Explanation
. Observation and NSAIDs
Explanation
Intramuscular hemangiomas are benign vascular malformations that often present with pain following activity due to vascular engorgement. Radiographs may show phleboliths (calcified thrombi), and the initial management is observation, activity modification, and NSAIDs.
Question 3482
Topic: 10. Pathology and Oncology
A 68-year-old female presents with a new, rapidly growing purple-red nodule on her right arm. She has a history of right mastectomy and axillary lymph node dissection for breast cancer 10 years ago, complicated by chronic severe lymphedema of the arm. What is the most likely diagnosis?
Correct Answer & Explanation
. Angiosarcoma
Explanation
Stewart-Treves syndrome is the development of an angiosarcoma in the setting of chronic lymphedema, classically occurring years after radical mastectomy with axillary node dissection. These are aggressive, high-grade vascular malignancies with a poor overall prognosis.
Question 3483
Topic: 10. Pathology and Oncology
What is the most common significant complication associated with harvesting autogenous iliac crest bone graft?
Correct Answer & Explanation
. Chronic donor site pain or sensory nerve injury
Explanation
Chronic donor site pain at the iliac crest harvest site is the most common significant complication of autogenous iliac crest bone grafting, often accompanied by sensory nerve injury (e.g., to the lateral femoral cutaneous nerve). While infection and hematoma are possible, chronic pain is a more persistent issue, affecting a substantial percentage of patients. Allergic reactions are not relevant for autograft.
Question 3484
Topic: 10. Pathology and Oncology
A 12-year-old boy presents with thigh pain and a periosteal 'onion skin' reaction on X-ray. Biopsy shows small round blue cells. Which of the following chromosomal translocations is most characteristic of this lesion?
Correct Answer & Explanation
. t(11;22)
Explanation
Ewing sarcoma is characterized by the t(11;22) translocation, which results in the EWS-FLI1 fusion protein. t(9;22) is seen in CML or extraskeletal myxoid chondrosarcoma, t(X;18) in synovial sarcoma, t(12;16) in myxoid liposarcoma, and t(2;13) in alveolar rhabdomyosarcoma.
Question 3485
Topic: 10. Pathology and Oncology
A 55-year-old patient has a large, aggressive-appearing lytic lesion in the proximal femur with endosteal scalloping and 'popcorn' calcifications. Biopsy confirms grade II conventional chondrosarcoma. What is the preferred primary treatment?
Correct Answer & Explanation
. Wide surgical resection
Explanation
Conventional chondrosarcomas (Grades II and III) are highly resistant to both chemotherapy and radiation therapy. The gold standard for treatment is wide surgical resection. Intralesional curettage is only appropriate for benign lesions (enchondromas) or very select low-grade (Grade I) tumors in appendicular locations.
Question 3486
Topic: 10. Pathology and Oncology
A 14-year-old boy presents with severe thigh pain and intermittent low-grade fevers. Radiographs show a permeative diaphyseal lesion of the femur with an 'onion-skin' periosteal reaction. A core biopsy confirms a small round blue cell tumor. Which of the following translocations and resulting fusion genes is most characteristic of this diagnosis?
Correct Answer & Explanation
. t(11;22) EWS-FLI1
Explanation
The clinical and radiographic presentation is classic for Ewing sarcoma. Over 85% of Ewing sarcomas are driven by a balanced translocation between chromosomes 11 and 22, t(11;22)(q24;q12), which results in the EWS-FLI1 fusion protein. t(X;18) is seen in synovial sarcoma; t(2;13) in alveolar rhabdomyosarcoma; t(12;16) in myxoid liposarcoma.
Question 3487
Topic: 10. Pathology and Oncology
A 60-year-old male with a history of prostate cancer (Gleason 7, stage T2N0M0, treated with prostatectomy 5 years prior) presents with new-onset severe mid-thoracic back pain, bilateral lower extremity weakness, and urinary retention. MRI of the spine shows a T7 vertebral body pathological fracture with significant spinal cord compression. What is the most appropriate initial management step?
Correct Answer & Explanation
. Immediate high-dose corticosteroids.
Explanation
This patient presents with acute onset neurological deficits (lower extremity weakness, urinary retention) due to suspected spinal cord compression from a pathological fracture secondary to metastatic prostate cancer. The immediate priority is to reduce spinal cord edema and prevent further neurological deterioration. High-dose corticosteroids (e.g., dexamethasone) are crucial for this purpose and should be administered immediately upon suspicion of cord compression. While urgent surgical decompression and stabilization (B) may be indicated, corticosteroids are the first step. Radiation (C) is a definitive treatment but is not immediate enough for acute cord compression. Biopsy (D) is important for diagnosis but must follow corticosteroids, especially if the primary is unknown or atypical presentation. Chemotherapy (E) is a systemic treatment and not for acute cord compression.
Question 3488
Topic: 10. Pathology and Oncology
A 14-year-old male presents with intermittent knee pain. Radiographs show an eccentric, lucent lesion with a sclerotic rim in the proximal tibia metaphysis, consistent with a non-ossifying fibroma (NOF). The lesion measures 3 cm in greatest dimension and occupies less than 50% of the cortical diameter. What is the most appropriate management?
Correct Answer & Explanation
. Observation with serial radiographs.
Explanation
Small, asymptomatic or mildly symptomatic non-ossifying fibromas (NOFs) occupying less than 50% of the cortical diameter are typically managed with observation due to their high rate of spontaneous regression. Surgical intervention (curettage and grafting) (B) is generally reserved for large, symptomatic lesions (e.g., >50% cortical diameter, risk of pathological fracture, persistent pain). En bloc resection (C) is overly aggressive for an NOF. Sclerosing agents (D) are not standard for NOFs. Radiation therapy (E) is not used for benign bone lesions due to risks. Therefore, observation with serial radiographs is the most appropriate initial management for this small, mildly symptomatic lesion.
Question 3489
Topic: 10. Pathology and Oncology
A 28-year-old female presents with knee pain and a lytic lesion involving the distal femur metaphysis/epiphysis, confirmed by biopsy as a Giant Cell Tumor (GCT). She has no evidence of metastatic disease. The lesion is Campanacci Grade III, with cortical breakthrough and soft tissue extension. Which of the following is the most appropriate surgical management strategy?
Correct Answer & Explanation
. Intralesional curettage with high-speed burr, followed by adjuvant therapy (e.g., cryosurgery or phenol) and bone graft/cement reconstruction.
Explanation
For Campanacci Grade III Giant Cell Tumor (GCT) without metastasis, the standard of care remains aggressive intralesional curettage (using a high-speed burr to remove microscopic remnants) combined with an adjuvant local therapy (such as cryosurgery, phenol, or argon beam coagulation) to decrease recurrence rates. Reconstruction is typically performed using bone cement (often preferred for its thermogenic effect on residual tumor cells and ease of monitoring for recurrence) or bone graft. While en bloc wide resection is an option for very aggressive, recurrent, or pathologically fractured lesions, it is associated with significant morbidity (e.g., higher rates of complications, limb shortening, prosthetic failure) and is generally reserved for cases where intralesional treatment is not feasible or has failed. Denosumab is useful pre-operatively to reduce tumor vascularity and solidify the rim, or for unresectable/recurrent GCT, but not as sole definitive management for a resectable Grade III lesion. Radiation therapy is generally reserved for unresectable or recurrent GCT in critical locations due to its risk of sarcomatous transformation.
Question 3490
Topic: 10. Pathology and Oncology
A 19-year-old female is diagnosed with an osteosarcoma of the proximal tibia. After neoadjuvant chemotherapy, she undergoes wide resection of the tumor. Given her age, activity level, and the bone defect size, which reconstructive option offers the best long-term functional outcome and durability?
Correct Answer & Explanation
. Endoprosthetic reconstruction.
Explanation
For a young, active patient with a large bone defect after wide resection of a tumor (like osteosarcoma of the proximal tibia), endoprosthetic reconstruction offers excellent early functional results and good long-term outcomes, particularly with modern designs. It allows for immediate weight-bearing and early mobilization, preserving joint function. While segmental allograft reconstruction (Option A) can be used, it carries higher rates of complications such as non-union, fracture, and infection, especially in active patients, and may require longer periods of protected weight-bearing. An articular spacer (Option B) is typically used for infection management or as a temporary measure. Arthrodesis (Option D) creates a stiff joint, significantly limiting function and impacting quality of life compared to joint-sparing reconstruction. Van Nes rotationplasty (Option E) is a viable and highly functional option, particularly for distal femoral tumors, where the ankle joint is rotated 180 degrees and serves as a knee joint. While functional, for a proximal tibia tumor, an endoprosthesis often offers a more 'normal' appearing limb and direct knee function, and is generally considered to provide excellent durability in this scenario.
Question 3491
Topic: 10. Pathology and Oncology
A 55-year-old male presents with persistent shoulder pain. Imaging reveals a large, lobulated, calcified mass in the proximal humerus with cortical destruction and soft tissue extension. Biopsy confirms a Grade II conventional chondrosarcoma. There is no evidence of metastatic disease. What is the cornerstone of definitive treatment for this tumor?
Correct Answer & Explanation
. Wide surgical en bloc resection.
Explanation
Chondrosarcomas, particularly conventional chondrosarcomas like Grade II, are typically resistant to both chemotherapy (Option B) and radiation therapy (Option A). Therefore, the cornerstone of definitive treatment for resectable chondrosarcoma is wide surgical en bloc resection with clear surgical margins. This aims to remove the entire tumor to prevent local recurrence. Intralesional curettage (Option D) with or without adjuvant therapy is generally reserved for low-grade, well-contained lesions (e.g., Grade I enchondromas or atypical cartilaginous tumors) where the risk of recurrence is low and wide resection would cause undue morbidity, but it is insufficient for a Grade II lesion with cortical destruction and soft tissue extension. Denosumab (Option E) is primarily used for Giant Cell Tumors and occasionally chordomas, but not typically for chondrosarcoma.
Question 3492
Topic: 10. Pathology and Oncology
A 58-year-old patient presents with a pathological fracture of the proximal humerus. Biopsy confirms metastatic renal cell carcinoma. Staging scans reveal multiple bone metastases, but no visceral involvement. He has good performance status. What is the most appropriate management strategy to prevent further pathological fractures and optimize quality of life?
Correct Answer & Explanation
. Denosumab and EBRT to painful or threatened sites
Explanation
Renal cell carcinoma metastases are notoriously resistant to conventional chemotherapy and often require higher doses of radiation, making a prophylactic approach with EBRT to threatened sites more effective than just treating an existing fracture. Denosumab (a RANKL inhibitor) is highly effective in preventing skeletal-related events (SREs) in patients with bone metastases, particularly from renal cell carcinoma, and has shown superiority over bisphosphonates in some studies for this indication. Surgical stabilization (e.g., IM nailing) would be indicated for an existing pathological fracture of a weight-bearing bone, but the question asks aboutpreventing furtherfractures and optimizing QOL with multiple sites. Radical nephrectomy is for primary tumor control if appropriate but doesn't directly address the widespread bone metastases for prevention of future fractures and QOL in this context.
Question 3493
Topic: 10. Pathology and Oncology
A 30-year-old immigrant from an endemic region presents with chronic back pain, night sweats, and weight loss. Imaging reveals a collapsed vertebral body at T10 with a large paravertebral abscess extending into the psoas muscle. A biopsy of the lesion shows granulomatous inflammation with caseating necrosis. What is the most appropriate initial management for this condition?
Correct Answer & Explanation
. Rifampicin, isoniazid, pyrazinamide, and ethambutol (RIPE therapy)
Explanation
The clinical presentation (chronic back pain, night sweats, weight loss in an immigrant from an endemic region) and imaging findings (collapsed vertebral body, paravertebral abscess, psoas involvement) with biopsy showing granulomatous inflammation and caseating necrosis are classic for Pott's disease (spinal tuberculosis). The cornerstone of treatment for spinal TB is multi-drug anti-tubercular therapy (e.g., RIPE therapy), typically for 9-12 months. Surgery (debridement, decompression, fusion) is reserved for neurological deficits, severe deformity, spinal instability, or failure of medical treatment, but medical therapy is always the initial and primary treatment. Broad-spectrum antibiotics alone are insufficient for TB.
Question 3494
Topic: 10. Pathology and Oncology
A 45-year-old presents with a recurrent giant cell tumor of the tendon sheath (GCTTS) in the flexor sheath of the index finger, previously excised twice. Imaging shows involvement of the A2 pulley and proximity to the neurovascular bundles. What is the most appropriate next step in management to minimize recurrence while preserving function?
Correct Answer & Explanation
. En bloc excision of the lesion including involved pulley, followed by A2 pulley reconstruction if necessary.
Explanation
Recurrent giant cell tumor of the tendon sheath (GCTTS), especially with involvement of critical structures like the A2 pulley and proximity to neurovascular bundles, requires meticulous and often aggressive excision to minimize recurrence. An en bloc excision, removing the tumor in one piece, including any involved adjacent structures (like the A2 pulley), and then reconstructing the pulley if needed, offers the best chance for local control while preserving digital function. Simple marginal excision carries a high recurrence risk in this scenario. Adjuvant radiation is not standard for benign GCTTS, and amputation is overly aggressive unless truly unavoidable.
Question 3495
Topic: 10. Pathology and Oncology
A 60-year-old presents with a high-grade pleomorphic undifferentiated sarcoma (PUS) in the proximal thigh, 8 cm in size, deep to fascia. No distant metastases are detected on staging imaging. What is the most critical component of the local treatment strategy for this tumor?
Correct Answer & Explanation
. Wide surgical excision with negative margins.
Explanation
For high-grade soft tissue sarcomas, wide surgical excision with achieving negative (R0) margins is the single most critical component for local disease control and improving patient survival. While neoadjuvant/adjuvant radiation therapy (often used to shrink the tumor and sterilize the surgical field, improving margin rates) and chemotherapy (for systemic control) play important roles in multimodal treatment, successful surgical removal with clear margins is paramount for preventing local recurrence. Regional lymph node dissection is not routinely indicated unless there is clinical evidence of lymph node involvement.
Question 3496
Topic: 10. Pathology and Oncology
A 4-year-old boy presents with a firm, fixed, non-tender mass in the distal femur. Radiographs show a lytic lesion with a narrow zone of transition, well-defined sclerotic margins, and a central nidus. The child complains of localized pain that is worse at night and consistently relieved by aspirin. What is the most likely diagnosis?
Correct Answer & Explanation
. Osteoid Osteoma
Explanation
The classic presentation of an osteoid osteoma includes nocturnal pain relieved by NSAIDs (especially aspirin), a small lytic lesion with sclerotic margins, and a central nidus visible on radiographs or CT. This distinguishes it from Ewing's sarcoma (Option A) and osteosarcoma (Option C), which are malignant, typically larger, and have more aggressive radiographic features without the classic pain response to aspirin. Brodie's abscess (Option D) is a subacute osteomyelitis, which can cause pain and lytic lesions but typically does not respond so dramatically to aspirin. Enchondroma (Option E) is usually asymptomatic unless fractured or very large.
Question 3497
Topic: 10. Pathology and Oncology
A 45-year-old male chronic smoker presents with a painful wrist mass that has gradually increased in size over 1 year. Radiographs show a lytic lesion in the distal radius with a 'soap bubble' appearance and an eccentric location. Biopsy confirms a giant cell tumor of bone. After extended curettage and local adjuvant therapy (e.g., cryosurgery or phenol), what is the most significant risk of local recurrence and what factor significantly influences it?
Correct Answer & Explanation
. Risk of recurrence is highest with intralesional curettage alone; local adjuvants reduce it but recurrence is still linked to the extent of surgical resection.
Explanation
Giant cell tumor of bone (GCTB) is a benign, locally aggressive tumor with a significant rate of local recurrence, particularly after intralesional curettage alone. While local adjuvant therapies (e.g., cryosurgery, phenol, argon beam coagulation) improve recurrence rates compared to curettage alone, recurrence remains a concern and is highly dependent on the completeness of the surgical resection (i.e., how thoroughly the tumor is removed). The extent of intralesional vs. en bloc resection significantly influences recurrence rates. Age (Option A) and smoking history (Option C) are not primary determinants of local recurrence. Radiation therapy (Option E) is generally reserved for unresectable or recurrent GCTB, or specific spinal lesions, due to the risk of sarcomatous transformation. Option D is incorrect as recurrence is a major concern.
Question 3498
Topic: 10. Pathology and Oncology
A 3-year-old child presents with a rapidly growing, painful mass in the distal femur. Biopsy confirms high-grade osteosarcoma. Staging studies reveal lung metastases. According to standard treatment protocols, what is the most critical component of therapy for this patient's long-term survival?
Correct Answer & Explanation
. Neoadjuvant chemotherapy followed by definitive surgery and adjuvant chemotherapy.
Explanation
Osteosarcoma is a highly aggressive malignant bone tumor. For patients with metastatic osteosarcoma (especially to the lungs, as is common), neoadjuvant (pre-operative) chemotherapy, followed by definitive surgical resection of both the primary tumor and metastatic lesions (if resectable), and then adjuvant (post-operative) chemotherapy, is the standard of care. This multimodal approach has significantly improved survival rates. Immediate amputation (Option A) without neoadjuvant chemotherapy would miss the opportunity to treat micrometastases and improve local control. Radiation therapy (Option B) is generally not the primary treatment for osteosarcoma, which is often radiation-resistant, and chemotherapy is crucial for systemic disease. Surgical resection of the primary tumor first (Option D) is generally not done without neoadjuvant chemo, and radiation to metastases is not the first line. Immunotherapy (Option E) is still largely experimental for osteosarcoma and not a standalone treatment.
Question 3499
Topic: 10. Pathology and Oncology
In a patient with a pathological fracture of the femur secondary to metastatic disease, what is the primary goal of intramedullary nailing?
Correct Answer & Explanation
. C. To provide immediate pain relief and restore function for palliation.
Explanation
For pathological fractures, especially in the context of metastatic disease, the primary goal of intramedullary nailing is palliation. This involves providing immediate pain relief, restoring stability to the limb, and allowing the patient to maintain or regain mobility and function for their remaining lifespan. While some healing may occur, definitive healing (A) is often not the primary objective, nor is promoting primary healing (D). Nailing does not prevent metastatic spread (B) or allow early discontinuation of cancer treatment (E).
Question 3500
Topic: 10. Pathology and Oncology
A 68-year-old male with a history of prostatic adenocarcinoma presents with progressive bilateral lower extremity weakness and new-onset urinary retention over 48 hours. MRI spine shows metastatic lesion at T8 causing severe spinal cord compression. His preoperative ECOG performance status is 2. Biopsy confirmed metastatic prostate cancer. He has a predicted survival of more than 6 months based on his oncology assessment. Which of the following surgical strategies offers the best balance of neurological preservation/recovery and local tumor control in this scenario?
Correct Answer & Explanation
. Posterior decompression, circumferential tumor resection via a single-stage posterior approach, and long-segment instrumentation (T6-T10).
Explanation
The patient has acute neurological deficit (motor weakness, urinary retention) due to spinal cord compression from a metastatic tumor, with a good prognosis (ECOG 2, >6 months survival). Decompressive laminectomy alone is largely considered inadequate for metastatic spine disease as it destabilizes the spine without providing sufficient decompression or tumor control and can lead to kyphosis and progressive instability. Steroids and radiation therapy are crucial but may be too slow for acute, severe neurological deficits, and radiation alone offers less robust local control for high-grade compressions. Posterior decompression and short-segment stabilization (C) might provide some stability but often fails to achieve wide enough decompression or adequate local control for aggressive tumors or those with significant anterior column involvement. Anterior corpectomy (E) addresses the anterior compression but is a separate surgery, and often requires a posterior stabilization in conjunction for optimal stability, and this option states 'alone'. The optimal strategy for a patient with severe spinal cord compression from metastatic cancer with good prognosis isposterior decompression, circumferential tumor resection (vertebral column resection or total en bloc spondylectomy if feasible and indicated), and long-segment instrumentation.This approach, often performed as a single-stage posterior surgery (separating posterior elements, corpectomy via a transpedicular or costotransversectomy approach, followed by reconstruction), offers the most comprehensive decompression, allows for the best chance of obtaining adequate surgical margins (local control), and provides robust immediate stability to prevent further neurological compromise and facilitate early mobilization and adjuvant therapies. Long-segment fixation (extending two levels above and two levels below the affected vertebral body) is generally preferred for metastatic disease to ensure durable stability and prevent construct failure.
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