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10. Pathology and Oncology MCQs

Practice Set 127 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 2521

Topic: 10. Pathology and Oncology
A 19-year-old woman has a painful right knee. A radiograph, MRI scan, CT scan, and histopathologic specimen are shown in Figures 24a through 24d. What is the most likely oncologic stage of the lesion?
. 2
. 3
. IIA
. IIB
. III

Correct Answer & Explanation

. III

Explanation

The patient has a high-grade osteosarcoma of the distal femur with a skip lesion, and pulmonary metastasis is seen on the CT scan. This corresponds to a stage III lesion according to the Musculoskeletal Tumor Society System as adopted from Enneking.

Question 2522

Topic: 10. Pathology and Oncology
A 35-year-old man has had progressive right knee pain for the past 2 months. An AP radiograph, bone scan, MRI scan, and photomicrograph are shown in Figures 34a through 34d. What is the most appropriate treatment of this lesion?
. Observation
. Extended curettage with adjuvant treatment
. Wide resection
. Radiation therapy
. Multimodal treatment including chemotherapy and surgery

Correct Answer & Explanation

. Extended curettage with adjuvant treatment

Explanation

This is a classic case of giant cell tumor of bone. The radiograph and the MRI scan reveal a purely lytic lesion in the medial femoral condyle. The lesion is well-demarcated without a rim of sclerotic bone. It is eccentrically located and abuts the subchondral bone. The lesion demonstrates increased uptake on a technetium TC 99m bone scan. These imaging studies are highly suggestive of giant cell tumor arising in its most common location. The photomicrograph confirms the diagnosis of giant cell tumor. Based on these findings, the most widely accepted treatment is extended curettage plus a local adjuvant such as polymethylmethacrylate bone cement, argon beam coagulation, liquid nitrogen, and/or phenol. Lackman RD, Hosalkar HS, Ogilvie CM, et al: Intralesional curettage for grades II and III giant cell tumors of bone. Clin Orthop Relat Res 2005;438:123-127.

Question 2523

Topic: 10. Pathology and Oncology

A 25-year-old woman has had pain and stiffness in her knee following a motor vehicle accident 9 months ago. The radiograph, CT scan, MRI scan, and biopsy specimen are shown in Figures 53a through 53d. What is the most likely diagnosis?

. Osteochondroma
. Osteoblastoma
. Osteomyelitis
. Heterotopic ossification
. Parosteal osteosarcoma

Correct Answer & Explanation

. Heterotopic ossification

Explanation

Heterotopic ossification may occur spontaneously or following trauma. The imaging studies and histology reveal mature fatty bone marrow and trabecular bone. Osteochondromas are cortically based with the medullary canal extending into the lesion. This is not evident in this patient. Also, no obvious cartilage cap is present. Parosteal osteosarcoma commonly occurs in the posterior distal femoral cortex but is ruled out by the lack of the typical fibrous stromal cells forming the low-grade malignant osteoid. The histology and clinical presentation eliminate osteomyelitis and osteoblastoma. Horne LT, Blue BA: Intra-articular heterotopic ossification in the knee following intramedullary nailing of the fractured femur using a retrograde method. J Orthop Trauma 1999;13:385-388. Stannard JP, Wilson TC, Sheils TM, McGwin G Jr, Volgas DA, Alonso JE: Heterotopic ossification associated with knee dislocation. Arthroscopy 2002;18:835-839.

Question 2524

Topic: Bone Tumors

A 27-year-old man has had pain in the right index finger for the past 9 months. The pain is completely relieved with ibuprofen. An AP radiograph and CT scan are shown in Figures 80a and 80b. What is the most likely diagnosis?

. Brodie's abscess
. Hyperparathyroidism
. Stress fracture
. Enchondroma
. Osteoid osteoma

Correct Answer & Explanation

. Osteoid osteoma

Explanation

Osteoid osteoma is a round or oval, well-circumscribed lesion with a radiolucent nidus. A small area of calcification may be present within the center of the nidus. The radiolucent nidus is surrounded by a thick rim of sclerotic bone. These diagnostic features are frequently better seen on CT. An increase in cyclooxygenase activity has been demonstrated within osteoid osteomas, which may explain why aspirin and other nonsteroidal anti-inflammatory drugs classically relieve the pain associated with these lesions. Kneisl JS, Simon MA: Medical management compared with operative treatment for osteoid-osteoma. J Bone Joint Surg Am 1992;74:179-185.

Question 2525

Topic: 10. Pathology and Oncology

A 44-year-old man has right hip pain. Radiographs reveal a radiolucent lesion of the femoral head and neck. An MRI scan shows no extraosseous tumor extension. A histopathologic photomicrograph of the biopsy specimen is shown in Figure 5. The chance of metastatic disease developing from this lesion is approximately what percent?

General Orthopedics Board Review 2026: High-Yield MCQs (Set 14) - Figure 20

. 0
. 5
. 25
. 50
. 75

Correct Answer & Explanation

. 5

Explanation

The risk of pulmonary metastasis from a benign giant cell tumor is estimated to be 5%.

Question 2526

Topic: 10. Pathology and Oncology

A 13-year-old patient has foot drop and lateral knee pain. AP and lateral radiographs and an MRI scan are shown in Figures 49a through 49c. A biopsy specimen is shown in Figure 49d. What is the preferred method of treatment?

. Wide resection alone
. Chemotherapy and radiation therapy
. Chemotherapy and wide resection
. Above-knee amputation
. Through-knee amputation

Correct Answer & Explanation

. Chemotherapy and wide resection

Explanation

The "sunburst" radiographic appearance suggests an osteosarcoma, and the histologic findings confirm the diagnosis with malignant cells surrounded by pink osteoid. MRI scans are not particularly helpful in the diagnosis of osteosarcoma but are mandatory for surgical planning. Osteosarcomas are high-grade sarcomas that are best treated with chemotherapy and wide resection. Even though the peroneal nerve is involved, limb salvage is indicated. Survival after limb salvage is equivalent to amputation, with better function. Goorin AM, Abelson HT, Frei E: Osteosarcoma: Fifteen years later. N Engl J Med 1985;313:1637. Link MP, Goorin AM, Miser AW, et al: The effect of adjuvant chemotherapy on relapse-free survival in patients with osteosarcoma of the extremity. N Engl J Med 1986;314:1600.

Question 2527

Topic: 10. Pathology and Oncology

Which of the following conditions is transmitted by an autosomal dominant trait?

. Multiple hereditary exostosis
. Ollier's disease
. Li-Fraumeni syndrome
. Maffucci's syndrome
. Retinoblastoma

Correct Answer & Explanation

. Multiple hereditary exostosis

Explanation

Multiple hereditary exostosis is transmitted by an autosomal dominant trait. Li-Fraumeni syndrome and retinoblastoma are autosomal recessive or associated with autosomal recessive mutations. No genetic predisposition to Ollier's disease or Maffucci's syndrome has been identified. Mirra J (ed): Bone Tumors: Clinical, Radiologic and Pathologic Correlations. Philadelphia, PA, Lea and Febiger, 1989, p 1627.

Question 2528

Topic: 10. Pathology and Oncology

An 18-year-old man has had an enlarging mass in his hand for the past 3 months. Radiographs, an MRI scan, and biopsy specimens are shown in Figures 54a through 54d. What is the most likely diagnosis?

. Bizarre parosteal osteochondromatous proliferation (BPOP)
. Osteosarcoma
. Ewing's sarcoma
. Enchondroma
. Infection

Correct Answer & Explanation

. Bizarre parosteal osteochondromatous proliferation (BPOP)

Explanation

Also known as Nora's lesion, BPOP is a benign osteocartilaginous tumor that almost always occurs in the hands and feet; one occurrence each in the femur and tibia has been reported. Although local recurrence is common after excision, metastases have not been reported. Abramovici L, Steiner GC: Bizarre parosteal osteochondromatous proliferation (Nora's lesion): A retrospective study of 12 cases, 2 arising in long bones. Hum Pathol 2002;33:1205-1210.

Question 2529

Topic: 10. Pathology and Oncology

A 38-year-old woman has a lesion on her left foot that has increased in size over the past 6 months. The clinical photograph is shown in Figure 17a, and a photomicrograph of the biopsy specimen is shown in Figure 17b. What is the most likely diagnosis?

. Kaposi sarcoma
. Squamous cell carcinoma
. Pigmented basal cell carcinoma
. Melanoma
. Basillary angiomatosis

Correct Answer & Explanation

. Melanoma

Explanation

Melanoma comprises 25% of lower extremity lesions and is the most common malignant tumor of the foot. The preferred treatment is wide resection. Hughes LE, Horgan K, Taylor BA, Laidler P: Malignant melanoma of the hand and foot: Diagnosis and management. Br J Surg 1985;72:811-815.

Question 2530

Topic: 10. Pathology and Oncology

A 7-year-old girl has pain and a mass in the left scapula. A MRI scan and biopsy specimen are shown in Figures 30a and 30b. After staging studies, initial management should consist of

. radiation therapy to the scapula.
. systemic chemotherapy.
. total scapulectomy.
. partial scapulectomy.
. intravenous antibiotics.

Correct Answer & Explanation

. systemic chemotherapy.

Explanation

The histology shows small round blue cells that are uniform in appearance; these findings are consistent with Ewing's sarcoma. The MRI scan shows infiltration of the marrow and a large surrounding soft-tissue mass. Based on these findings, the management of choice is systemic chemotherapy. Local control of the primary lesion is addressed by either surgical resection or radiation therapy or a combination of the two after the patient receives systemic chemotherapy. The clinical, radiographic, and histologic presentation of Ewing's sarcoma often can be confused with osteomyelitis. The histology shows an absence of inflammatory cells. Grier HE: The Ewing family of tumors: Ewing's sarcoma and primitive neuroectodermal tumors. Pediatr Clin North Am 1997;44:991-1004.

Question 2531

Topic: 10. Pathology and Oncology

A 60-year-old female with metastatic breast cancer presents with progressive back pain. The Spinal Instability Neoplastic Score (SINS) is utilized to evaluate her need for surgical stabilization. Which of the following factors is incorporated into the SINS calculation?

. Spine location, pain characteristics, and bone lesion type (lytic vs. blastic)
. Systemic tumor burden and overall patient survival expectancy
. Number of extraspinal metastases and visceral involvement
. Chemosensitivity and radiosensitivity of the primary tumor
. Patient age and American Society of Anesthesiologists (ASA) class

Correct Answer & Explanation

. Spine location, pain characteristics, and bone lesion type (lytic vs. blastic)

Explanation

The SINS criteria assess spinal stability in neoplastic disease based on 6 parameters: location of the lesion, pain characteristics, bone lesion type (lytic/blastic), radiographic spinal alignment, degree of vertebral body collapse, and posterolateral involvement of spinal elements.

Question 2532

Topic: 10. Pathology and Oncology

A 45-year-old woman has had right wrist pain for the past 2 months. A radiograph, bone scan, and MRI scan are shown in Figures 66a through 66c, and a photomicrograph is shown in Figure 66d. What is the most likely diagnosis?

. Osteomyelitis
. Giant cell tumor
. Osteosarcoma
. Chondroblastoma
. Histiocytosis

Correct Answer & Explanation

. Giant cell tumor

Explanation

The radiograph shows a purely radiolucent lesion without matrix mineralization in the epiphysis of the distal radius. The lesion is "hot" on bone scan, and the MRI scan reveals cortical destruction with a soft-tissue mass. These findings are most consistent with giant cell tumor. The distal radius is a common location for giant cell tumors. The other options would be very uncommon in this location in a 45-year-old patient. The photomicrograph demonstrates multinucleated giant cells in a sea of mononuclear cells. The nuclei of the giant cells and the nuclei of the mononuclear stromal cells are identical. This feature helps distinguish giant cell tumor from other lesions that might contain giant cells. Cheng CY, Shih HN, Hsu KY, et al: Treatment of giant cell tumor of the distal radius. Clin Orthop Relat Res 2001;383:221-228.

Question 2533

Topic: 10. Pathology and Oncology

Osteopetrosis is characterized by dense, brittle bones due to defective osteoclastic bone resorption. Mutations in which of the following genes are most commonly responsible for the malignant infantile form of this disease?

. COL1A1
. FGFR3
. RUNX2
. TCIRG1
. COMP

Correct Answer & Explanation

. TCIRG1

Explanation

Malignant infantile osteopetrosis is most commonly caused by mutations in the TCIRG1 gene. This gene encodes the a3 subunit of the vacuolar proton pump (V-ATPase) essential for acidifying the resorption lacunae.

Question 2534

Topic: 10. Pathology and Oncology

A 15-year-old girl has had a painful mass on the medial aspect of her left thigh for the past 5 years. The pain is present only when she is performing athletic activities and is completely relieved with rest. A radiograph and MRI scan are shown in Figures 29a and 29b. The patient and her parents would like to have the mass removed. What further diagnostic studies are required prior to considering surgical resection?

. Bone scan
. CT
. Needle biopsy
. Incisional biopsy
. No further tests are needed

Correct Answer & Explanation

. No further tests are needed

Explanation

The radiograph and MRI scan show a pedunculated lesion arising from the medial aspect of the distal femoral metaphysis. The cortex of the lesion is contiguous with the cortex of the underlying normal bone. Similarly, the medullary canal of the lesion is contiguous with that of the normal bone. These findings are diagnostic of osteochondroma. Rarely a secondary chondrosarcoma can arise in a preexisting osteochondroma. This diagnosis is suggested by identifying a cartilage cap that is greater than 1.5-cm thick in a skeletally mature patient. MRI is the best study to rule out a secondary chondrosarcoma. CT also may be used for this purpose but is not indicated in this patient because an MRI has already been obtained. A bone scan is not useful to identify a secondary chondrosarcoma. Similarly, there is no role for biopsy in this patient. No further tests are needed. Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 103-111.

Question 2535

Topic: 10. Pathology and Oncology

Figures 52a and 52b show the radiographs of a left proximal femoral lesion noted serendipitously following minor trauma to the left hip. The patient has no thigh pain and is fully active without limitation. What is the most likely diagnosis of this bony lesion?

. Chondroblastoma
. Enchondroma
. Giant cell tumor
. Fibrous dysplasia
. Osteoblastoma

Correct Answer & Explanation

. Fibrous dysplasia

Explanation

The radiographs reveal a geographic lesion of the proximal femur with the classic "ground glass" appearance noted in fibrous dysplasia. This intramedullary lesion is modestly expansile, demonstrates some minimal cortical thinning, and has no aggressive features. Chondroblastoma, giant cell tumor, and osteoblastoma are more lytic in appearance, and the location is not typical for giant cell tumor or chondroblastoma. While enchondroma may be considered, the uniform ground glass appearance, lack of punctuate mineralization, and distinct margination of the lesion make that diagnosis less likely.

Question 2536

Topic: 10. Pathology and Oncology

An orthopedic oncologist is performing a resection of a soft tissue sarcoma located within the femoral triangle. Which of the following defines the lateral border of this anatomic region?

. Adductor longus
. Sartorius
. Inguinal ligament
. Pectineus
. Tensor fasciae latae

Correct Answer & Explanation

. Sartorius

Explanation

The femoral triangle is bordered superiorly by the inguinal ligament, medially by the medial border of the adductor longus, and laterally by the medial border of the sartorius muscle.

Question 2537

Topic: 10. Pathology and Oncology

A patient experiences sudden cardiovascular collapse and malignant arrhythmias shortly after a regional nerve block using bupivacaine. Advanced cardiac life support is initiated. Which of the following is the most critical initial targeted antidote for systemic toxicity from this medication?

. Intravenous calcium gluconate
. Intravenous lipid emulsion 20%
. Flumazenil
. Naloxone
. Intravenous glucagon

Correct Answer & Explanation

. Intravenous lipid emulsion 20%

Explanation

Local anesthetic systemic toxicity (LAST), particularly severe with bupivacaine, is primarily treated with an intravenous lipid emulsion 20% bolus and infusion. The lipid emulsion acts as a 'lipid sink' to draw the highly lipophilic local anesthetic out of the cardiac tissue.

Question 2538

Topic: 10. Pathology and Oncology



A 56-year-old woman with a history of metastatic breast cancer presents with progressive paraparesis and hyperreflexia in her lower extremities over the last 3 days. Her systemic disease is otherwise well-controlled, and her expected survival is greater than 1 year. MRI reveals a pathological fracture at T8 with high-grade epidural spinal cord compression caused by tumor mass. Based on the Patchell trial criteria, what is the most appropriate initial treatment?

. High-dose systemic chemotherapy
. Emergent primary radiotherapy alone
. Intravenous bisphosphonate therapy
. Surgical decompression and stabilization followed by radiotherapy
. Palliative observation with high-dose corticosteroids

Correct Answer & Explanation

. Surgical decompression and stabilization followed by radiotherapy

Explanation

According to the landmark randomized trial by Patchell et al., patients with high-grade epidural spinal cord compression from solid tumors (like breast cancer), who have a life expectancy > 3 months and neurologic deficit, have significantly better functional outcomes with direct surgical decompression and stabilization followed by radiotherapy compared to radiotherapy alone.

Question 2539

Topic: 10. Pathology and Oncology

A previously healthy 13-year-old girl has had thigh pain for the past 3 weeks. The radiograph shown in Figure 47a reveals a lesion in the right femur. A bone scan and CT scan of the chest show no evidence of other lesions. A biopsy specimen is shown in Figure 47b. What is the most likely diagnosis?

. Ewing's sarcoma
. Lymphoma of bone
. Metastatic neuroblastoma
. Langerhans cell histiocytosis
. Osteomyelitis

Correct Answer & Explanation

. Langerhans cell histiocytosis

Explanation

The patient has Langerhans cell histiocytosis that may be solitary (eosinophilic granuloma) or associated with systemic illness (Hand-Schuller-Christian disease and Letterer-Siwe disease). The solitary form of the disease, eosinophilic granuloma, typically affects patients in the first three decades of life. Radiographically, it is characterized as a well-defined, lytic, "punched out" intramedullary lesion. Histologically, two cell types, eosinophils and Langerhans cells, are seen. The Langerhans cells are seen as mononuclear histiocyte-like cells with oval nuclei with well-defined round or oval cytoplasm. A prominent nuclear groove can be seen in most of the nuclei (coffee bean nuclei). A mixture of inflammatory cells and lipid-laden foam cells with nuclear debris may be present as well. The lack of nuclear atypia and atypical mitoses excludes malignant conditions such as Ewing's sarcoma, lymphoma of bone, and metastatic neuroblastoma. The lack of acute inflammatory cells excludes the diagnosis of osteomyelitis. The eosinophils have bi-lobed nuclei and granular eosinophilic cytoplasm. Dorfman H, Czerniak B: Bone Tumors. St Louis, MO, Mosby, 1988.

Question 2540

Topic: 10. Pathology and Oncology

Figures 56a through 56c show the radiograph, CT scan, and biopsy specimen of a 44-year-old man who underwent chemotherapy and radiation therapy for lymphoma of the distal femur 20 years ago. His current problem is most likely related to

. steroid-induced osteonecrosis.
. radiation therapy with secondary malignancy.
. recurrence of the lymphoma.
. radiation osteitis.
. a primary lung tumor.

Correct Answer & Explanation

. radiation therapy with secondary malignancy.

Explanation

The patient has changes consistent with radiation therapy to the femur, including osteopenia and an aggressive appearing neoplasm. The tumor is most likely a radiation-induced sarcoma. This is more likely than recurrent lymphoma at this late date. It is not related to steroid use or a primary lung tumor. Mirra J (ed): Bone Tumors: Clinical, Radiologic and Pathologic Correlations. Philadelphia, PA, Lea and Febiger, 1989, p 353.

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